GIS BASED GEOMORPHOLOGICAL ANALYSIS OF DEWANA BASIN, SULAIMANI GOVERNORATE, KURDISTAN REGION, NE IRAQ
A Thesis Submitted to the Council of Faculty of Science and Sciences Education School of Science at the University of Sulaimani in Partial Fulfillment of the Requirements for the Degree of Master of Science in Geology
BY Lanja Hossain Abdullah Ahmed B.Sc. Geology (2005), University of Sulaimani
Supervised By Dr. Basim A. J. Al-Qayim Professor
Jozardan, 2712
May, 2012
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اَل َّالر ْ لْحنِ َّالرحيِ بِ ْسمِ ل ّ ِ ت ِ¤لوإ لَلِ ون ِإ لَل ِاإلبل ِ لك ْي لف ِ ُخلقل ِْ ألفلالِي ل ُنظ ُر ل ت ِ ¤لوإ لَل ِالْج لبال ِ لك ْي لفِ الس لماء ِ لك ْي لف ُِرف لع ِْ َّ ت ِ¤لوإ لَل ل تِ¤فل لذكِّ ْرِ ِاأل ْرض ِ لك ْي لف ُِسط لح ِْ نُصب ل ِْ إن َّ لماِأل ل نتِ ُم لذكِّرِِ¤ صدقِاَلِالعظي ّ سورةِالغاش يةِ,اآلايتِ(ِ)ِ17-71
Do they not look at the Camels, how they are created? ¤ And the sky how it is raised? ¤ And at the mountains how they are fixed firm? ¤ And at the earth how it is spread out? ¤ So remind you are only a reminder¤
Dedicated to: * My dears Father and Mother * My beloved husband *My brothers and sisters
LANJA
ACKNOWLEDGEMENTS Thanks to Allah who supported me to carry out my research work as well as my course studies. Much appreciation to my supervisor, professor Dr. Basim Al-Qayim for his continuous supervision, kindness and valuable help during this study. My sincere thanks and appreciations are due to the presidency of Sulaimani University, especially the deanery of Science faculty and head of Geology department, namely Dr.Kamal Haji and Dr.Diary Ali for their facilities and administrative support. My endless thanks to Dr. Hussein Darwesh, in Sulaimani Technical College, for all of his time, energy, and assistance with all the GIS work in my study. I’d like to express my gratefulness for Swedish research center for sponsoring a part of the field work and supplying facilities. I am greatly indebted to the State Company of Geological Survey and Mining in Baghdad for their various support and highly cooperative in providing some of the data used for this study, with special thanks to Mr.Varoujan K. Sissakian, Dr.Saffa A. Fouad, Mr.Younus Alsaadi, Mrs.Rand Al-Saati, Mr.Talal Hassan, Mr.Ahmed Faeq, Mr.Taha yaseen. My great thanks also to Dr.Hekmat Daghstani in Mousil University for his suggestion and support. Special thanks for Dr.Saad Al-Saadi in University of Baghdad for providing maps and references. Special thanks to Dr. Ghafor Ameen, Dr.Ibrahem Mohammed, Dr.Fazil Lawa, Mr.Musher Mustafa, Mr.Azhar Khalil, Mr.Soran Othman, Mr.Sanaw Salih, Mr.Fahmy Othman, Mr.Jabar in the University of Sulaimani-Faculty of Science-Geology department for their help during this research. I extend my deepest gratitude and appreciation to my beloved husband, Ballanbo, as well as my entire family for all of their love, continuous moral support, encouragements and care during this study which without their assistance would have been much more difficult. Thank to anyone who helped me. I
Abstract This research utilizes the integrated remote sensing and geographic information systems (GIS) in geomorphological study of Dewana drainage basin, Sulaimani Governorate of the northeastern part of Iraq, which is located between longitudes (45o14’00”, 45 o43’00”) E and latitudes (35o03’00”, 35o26’00”) N, and covers about (606 km²). It is bounded to the northeast by the ridge of Baranan mountain and to the southwest by Sagerma mountain. Satellite images as well as Digital Elevation Model with topographic, geologic, and structural maps were used in addition to field investigations to perform a geomorphological analysis and classification. The study is mainly based on quantitative and descriptive approaches; both integrate a number of different methods and data to reach the goals of this study. Arc GIS 9.3 was used to digitizing, measuring and drawing the spatial data of the different analyses. Detailed morphometric analysis was applied to the Dewana basin, using variable geomorphological and hydrogeomorphological parameters, by calculating network aspects from two sets of topographic maps at scale of 1:20,000 and 1:50,000. All groups of morphometric parameters were used such as: linear, relief and aerial parameters. Morphometric analysis results are discussed and correlated with each other and to standard value to evaluate fluvial-geomorphic evolution of the basin. The study shows that the Dewana basin of the 6th order drainage basin, with relatively, high values of drainage density and basin relief values. This implies that surface runoff is not rapidly removed from the basin, making it susceptible to sheet flooding, gully erosion and landslides. According to the elongation ratio and circularity ratio of the basin, it is elongated in shape, which reflects strong structural controls on the morphology of the basin. Drainage pattern is dominated by dendritic, sub-
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parallel, sub-trellis types which reflect structural controls in addition to variable lithologic characters of the basin rocks. General geomorphic mapping and classification of the studied basin using genetic origin as a base for the grouping show that it includes several groups of landforms which are classified into five major units. These units are: structural origin unit, denudational origin unit, structural-denudational origin unit, fluvial origin units, and anthropogenic origin unit. These units with their subunits were mapped on a 1:150,000 scale to show special distribution and relation between the different landforms. Discussion of five units and description of its landforms were given in term of their relation to geology, topography, drainage network as well as originating geomorphic process. The dominating geomorphic processes over the basin area is fluvial which generates the most pronounced landform groups and subunits such as: Dry valley deposits, Flood plain, Valley fills, River terraces, Alluvial fans, Gulleys, Badlands. Mild weathering and strong erosion processes shape the details of these landforms. The impact of the geomorphological features and processes on the human activity of the Dewana basin community is evaluated to show the application value of such study. Geohazards of the basin are discussed which include mass wasting effect on high and moderate slopes. Evaluation of slope stability was attempted through mapping of slope classes. Unstable slopes are confined to the major ridges which surround the basin from northeast and southwest. Other applied aspects such as flooding, water resources management, irrigation planning and soil erosion are discussed and evaluated in the light of the results of the geomorphic analysis and available data.
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CONTENTS Acknowledgements ......................................................................................................... I Abstract ........................................................................................................................... II Contents ......................................................................................................................... IV List of Figures ................................................................................................................ VI List of Tables ................................................................................................................ IX Chapter One: Introduction 1.1 1.2 1.3 1.4 1.5
Research Problems …………………………………………………………………….1 Previous Works………………………………………………………………………...1 Location of Study Area………………………………………………………………...2 Aim of the Study……………………………………………………………………….4 Data and Research Methods……………………………………………………………4
Chapter Two: Components of Geomorphological Environment 2.1 Topography…………………………………………………………………………….7 2.2 Geology………………………………………………………………………………...7 2.2.1 Tectonic and Structural Setting……………………………………………………....7 2.2.2 Stratigraphy………………………………………………………………………....10 2.3 Climate………………………………………………………………………………..22 2.4 Soil…………………………………………………………………………………….25 2.5 Vegetation Cover……………………………………………………………………...27 2.6 Water Recourses………………………………………………………………………29 Chapter Three: Drainage Basin Analysis 3.1 Dewana Basin…………………………………………………………………………33 3.2 Network Analysis …………………………………………………………………….35 3.3 Morphometric analysis………………………………………………………………..42 3.3.1 Linear Morphometric Relationship………………………………………………….44 3.3.2 Areal Morphometric Relationship…………………………………………………...50 3.3.3 Relief Morphometric Relationship…………………………………………………..54 3.4 Longitudinal Profiles of Dewana Stream……………………………………………..55 3.5 Interpretation of Results……………………………………………………………….57
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Chapter Four: Geomorphic Analysis 4.1 Introduction………………………………………………………………………...…60 4.2 Geomorphic Classification and Mapping …………………………………………….60 4.2.1 Units of Structural Origin…………………………………………………………...62 4.2.2 Units of Dunudational Origins……………………………………………………...65 4.2.3 Units of Structural-Dunudational Origin …………………………………………...67 4.2.4 Units of Fluvial Origin ……………………………………………………………..70 4.2.5 Units of Anthropogenic Origin………………………………………………….......73 4.3 Geomorphic Processes………………………………………………………………...75 4.3.1 Endogenetic processes……………………………………………………………….76 4.3.2 Exogenetic processes………………………………………………………………...76 Chapter Five: Geomorphic application 5.1 Preface…………………………………………………………………………………87 5.2 Water Resources Management………………………………………………………...89 5.3 Slope Stability Evaluation……………………………………………………………..92 5.4 Geohazard of Dewana Basin…………………………………………………………..96 Conclusions and Recommendations......................................................................…...100 References ………………………………………………………...…………………103
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List of Figures Figure No. Figure Title Page No. 1.1 Location map of the the study area ......................................................... 3 2.1 Digital Elevation Model of Dewana basin……………………………… 8 2.2 Tectonic map of northern Iraq showing location of the study area (after Jassim and Goff, 2006) ……………………………………………… 9 2.3 Lineament map of Dewana basin (stream network based on digitizing 1:50,000 scale topographic map). …………………………………… 11 2.4 Geological map of Dewana basin (modified after Ma’ala, 2008)…….. 13 2.5 Geological cross section of Dewana basin passing through Kalosh anticline from A to B (modified after Stevanovic and Markovic, 2003).. 14 2.6 Kolosh and Sinjar formations in the core of Sagrma anticline………… 15 2.7 Kolosh and Sinjar formtains outcrops, in kalosh anticline……………. 15 2.8 Pila Spi Formation in the NE limb of Sagerma anticline……………... 15 2.9 Fatha Formation in the northestern limb of Sagerma anticline………. 17 2.10 Gypsum lenses in Fatha Formation…………………………………. 18 2.11 Successive protruding strike ridges forming a common ridge and valley landscape in Injana Formation, estern Kalosh anticline, center of Dewana basin………………………………………………………………….. 18 2.12 Sandstone caped the siltstone in Injana Formation, near Astel village, west of Dewana basin…………………………………………………. 18 2.13 Alternating sandstone and pebbly sandstone of Mukdadiyah Formation, Dewana basin………………………………………………………….. 19 2.14 Conglomerate in Bi Hassan Formation, north of Qara Dagh………….. 19 2.15 River terraces along Dewana stream, near Dewana village…………….. 21 2.16 Flood plain Deposit, near Kalosh village………………………………. 21 2.17 Morphogenetic region of Peltier’s (1950) diagram (red: climatic parameters Darbandikhan station, blue: climatic parameter Sulaimani station)…… 23 2.18 Distributions of soil classes in the study area (compiled from Buring, 1960 and Hadad et al., 2009)…………………………………………….…… 26 2.19 Oak trees in the Sagerma anticline NW of study area…………………. 28 2.20 Dense bushes along Dewana Stream………………………………….. 28 2.21 Location of wells and springs related to the villages in Dewana basin (wells from Ground water directorate/Sulaimani, springs from digitizing 1:20,000 topographic maps)……………………………………………. 30 3.1 Dewana basin drainage network and sub-basins (Stream from digitizing 1:50,000 scale topographic map). ………………………………………. 34 3.2 Chamy Gora networks prepared from different scales A. 1:20,000, B. 1:50,000………………………………………………………………….. 36 3.3 Chamy Wara Qarawagh network prepared from different scale A. 1:20,000 , B. 1:50,000……………………………………………………………….. 37 3.4 Drainage network and their relation to the bed attitude…………………. .. 38 VI
Figure No. Figure Title Page No. 3.5 Different types of drainage patterns of Dewana Basin……………… 40 3.6 Satellite image showing dendritic drainage pattern in northern part of Dewana basin………………………................................................... 41 3.7 Satellite image showing Sub-parallel drainage pattern in the southwestern side of Baranan ridge, Dewana basin……………………………….. 41 3.8 Showing relationships between stream order and stream numbers of studied basin and two sub basins…………………………………… 47 3.9 Relationship between mean stream length and stream order and whole Basin………………………………………………………………. 49 3.10 Longitudinal profile of Dewana stream……………………………… 57 4.1 Geomorphological map of Dewana basin……………………………. 63 4.2 Show satellite image and topographic profiles of Kalosh anticline…… 64 4.3 Flatiron on northeastern limp of Sagerma anticline………………….. 65 4.4 Wind gap across Qara Dagh mountain………………………………… 65 4.5 Sattelite image shows ridges and furrows in Gullan mountain foot slope. 66 4.6 Badland landscape in the study area……………………………………. 67 4.7 Erosional core of Sagerma anticline……………………………………. 68 4.8 Erosional escarpment flanked the Sagerma anticlinal core…………… 68 4.9 Gully erosion on Barzy Dolan mountain, northern of Dewana basin…. 69 4.10 Structural benches in denudation hill area, Dewana basin…………….. 69 4.11 Flood plain near Tazade village between Baranan and Kalosh mountain. 70 4.12 Channel deposits, Dam site location southern of study area……………. 72 4.13 Lower river terrace of Dewana stream, near Dewana village………… 72 4.14 High level of river terraces with rock fans in the lower most part of the scarp, near Dewana village……………………………………………. 72 4.15 Satellite image of old alluvial fan near Balkha village southeast of Qara Dagh mountain…………………………………………………………. 73 4.16 Constructing a dam project along Dewana downstream………………. 74 4.17 Terraces farming, Dukan village,Dewana basin………………………. 74 4.18 Naramsyn sculpture on Pila Spi limestone Formation, Darbandi Gawr.. 75 4.19 Peilter’s diagrams show weathering regions, red point is study area (Peilter, 1950)………………………………………………………… 77 4.20 Rounded and sub-rounded gravels in a stream bed in lower reach of Dewana stream……………………………………………………….. 78 4.21 Claystone between limestone beds in Fatha Formation promotes sliding when it becomes wet, road to Qopy Qara Dagh northwestern part of the studied area…………………………………………………………….. 78 4.22 Rock shattering and disintegration by thermal expansion (A) and growth of tree roots (B)…………………………………………………………. 79 4.23 Development of spheroidal weathering of sandstone of Injana Formation. 79 4.24 Karren, formed due to water solution by rain water………………… 80 4.25 Alveoli developed in limestone of Pila Spi Formation………………… 81 4.26 Well-developed eroding tafoni in Injana sandstone ………………… 81 VII
Figure No. Figure Title Page No. 4.27 Rock slide on detritus Limestone of Fatha Formation, along the road to Qopy Qara Dagh, NW of study area……………………………… 82 4.28 Rock fall along Pila Spi cliff, Sagerma mountain……………………. 83 4.29 Down slope creep as evidenced by bend of tree, near Qaraman village.. 83 4.30 Active rill erosion, near Dukan village……………………………….. 85 4.31 Bottle neck showing head ward erosion near Wlyan village…………. 85 4.32 Panorama view of down cutting by Dewana stream branch………….. 86 4.33 Bank erosion of Dewana stream along its meander way……………… 86 4.34 Channel deposits (point bar) at the convex side of Dewana stream, near Kalosh Village…………………………………………………………. 86 5.1 Land use map of Dewana basin (compiled from land use map, scale1:1,000,000, General Directorate of Forest/Sulaimani)…………. 88 5.2 Plastic houses in fertile bed, Daluja village…………………………….. 89 5.3 Show cross section of Karez (by Samuel Bailey in www.Wikipedia.org). 91 5.4 Weir as irrigation project near Daluja village…………………………….. 92 5.5 Slope map of Dewana basin……………………………………………… 93 5.6 Hazard map of Dewana basin (Sissakin et al., 2008). …………………… 97 5.7 Possible land slide in Fatha Formation along bedding plane…………….. 98 5.8 Rock fall in Injana Formation at river bank………………………………. 98
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List of Tables Table No. 2.1
2.2
2.3
2.4
3.1 3.2 3.3 3.4 5.1 5.2
Table Title Average maximum and minimum temperature and mean annual temperature ° C in Sulaymani station for years (2000-2010) (Sulaimani Metrological Directorate)………. … Average maximum and minimum temperature and mean annual temperature °C in Darbandikhan station for years (2007-2009) (Sulaimani Metrological Directorate)…………… Average monthly and mean annual rainfall in (mm) over Sulaimani metrological station for years (2000-2010) (Sulaimani Metrological Directorate)………………………… Average monthly and mean annual rainfall in (mm) over Darbandikhan metrological station for years (2007-2009) (Sulaimani Metrological Directorate)………………………. … Formula adopted for the computation of morphometric parameters of Dewana basin…………………………………. Linear Morphometric parameters of Dewana Basin and subbasins based on maps of scale 1:50,000……………………… Areal morphomertic parameter of Dewana basin and subbasins based on maps of scale 1:50,000……………………… Relif Morphometric parameter of Dewana basin and subbasins based on maps of scale 1:50,000…………………...... Zink (1988-1989) classification for earth slope with geomorphic sub-units……………………………………………………… … Showing area covered by each class in the study area…………. …
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CHAPTER ONE
INTRODUCTION
CHAPTER ONE INTRODUCTION 1.1 Research Problems Dewana basin as a part of Sulaimani area lacks detailed geomorphological studies that include geomorphological mapping and evaluation. As the area faces rapid development and growth, similar kind of studies become important and necessary to establish a comprehensive background for any environmental, agricultural and even urban developments. Contemporary researches on Kurdistan’s river basins have yet to compile a comprehensive database of each stream’s geographical and geomorphological attributes. A preliminary application of morphometric analysis will aid in forming such a compilation of data into a GIS-based format that is both usable and applicable to modern future researches and studies in the similar field.
1.2 Previous Works Relating to geomorphological studies there are no such studies, except few paragraphs that they are unpublished reports in different fields like soil, ground water, geology and hydrology. Because of the importance of structural geology and rock types and their relation to geomorphological phenomena, a review of the most of the geological studies in the study area and NE of Iraq was carried out. These studies can be summarized as follows: Buringh (1960), classified Iraqi soil and give a general review for soil in the study area. Al Omary and Sadiq (1977), provide general review of the geology of Northern Iraq. They emphasize that the folds are formed during upper cretaceous because of compressional force which reaches it’s minimum at Pliocene, these are responsible for most of the geomorphological landform in the area. Majed (1988), used remote sensing technique in finding the relation between lineament and earthquake activities in north eastern Iraq. She confirmed that there are good relations between surface lineament and subsurface structures, such as faults extending to basement rocks.
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CHAPTER ONE
INTRODUCTION
Al -Jabory (1991), studied hydrology and geomorphology of Diyala river basin, and he studied morphometric analysis of important sub-basins in the area. He recognized some geomorphological unit within the basin. Armaghani (1992), studied morphotectonics of Darbandikhan area by using remote sensing (including study area). Stevanovic and Maran (2002), studied the karst and cave of northwestern Zagros (northern Iraq) including the study area. Markovic and Stevanovic (2003), conducted an environmental study of north Iraq covering analysis of geology, hydrology, geomorphology and climate as a part of FAO works/Sulaimani and Arbil sections, that they mentioned our study area. Lawa (2004), had studied
sequence stratigraphy of Middle Paleocene-Midle Eocene
in the Sulaimani district, with sections selected nearby the study area. He discussed in details facies associations and biostratigraphic correlations of paleogene Formation of the area. Karim and Ali (2005), studied the origin of dislocated limestone blocks on the slope side of Baranan (Zirgoez) homocline. Working group (2009 a), in State Company of Geological Survey and Mining, did a survey study of geologically and geophysically for constructing a dam along Dewana perennial stream. Hamamin (2011), studied the hydrology of Basara basin, and developing a vulnerability map of ground water of the basin north of the study area.
1.3 Location of Study Area Dewana basin is located in Sulaimani Governorate, NE Iraq along Dewana perennial stream that flows between Qara Dagh and Baranan mountains and drain to Diyala river. The area is located between 45o14’00” E and 45 o43’00” E longitudes, 35o03’00” N and 35o26’00” N latitudes, with a total area of 606 Km 2. Most of the study area is characterized by mountain ranges stretching from southeast to northwest with general altitude ranging from 1878 m a.s.l at the highest point in Qala Gila Nawa peak to 360 m a.s.l at the confluence with Diyala river (Fig. 1.1).
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Figure 1.1: Location map of the study area.
CHAPTER ONE INTRODUCTION
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CHAPTER ONE
INTRODUCTION
1.4 Aims of the Study The current study aims at: 1. To conduct a preliminary geomorphological evaluation and analysis of Dewana basin in hope to establish a physical environmental data base for future projects or development in the area. The geomorphological analysis is to be conducted through:
Field studied of landforms and their relation to different geologic features.
Classification and grouping of landforms of the study area, according genetic origin.
Evaluating lineaments and their relation to the geomorphological development of the area.
Basin geomorphological mapping using remote sensing data.
2. To present a way in which computer tools such as Geographic Information System (GIS) to be used together with remote sensing data, to contribute to the analysis and representation of the information required for geomorphological analysis of Dewana basin. Developing a GIS digital data base for the area containing geographical orientation, properties and relations, that can be easily update or integrate with other new data, and reusing those data in the different applications in the futures. 3. Evaluating the geomorphological process impacts on environmental and other human activities in the area such as:
Water resources development of the basin.
Soil erosion and flood hazards.
Slope stability and mass wasting assesment
Agricultural land use and irrigation applications for the basin.
1.5 Data and Research Methods 1.5.1 Data The data sets used in this study consist of: Quick Bird satellite image (0.6, 0.6 Cell size). DEM from ASTER image (30, 30 Cell size). Landsat TM images (7-bands). Finished digital image anaglyph in order to carry out the stereo-observation through the computer screen by using red and blue glasses.
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CHAPTER ONE
INTRODUCTION
Topographic maps (scale 1:100,000, 1:50,000 and 1:20,000 from Directorate of General Surveys, Baghdad). Geological map of the Sulaimani Quadrangle sheet N-38-j (scale 1:250,000) by Ma’ala (2008). Geomorphological map of Iraq (Scale 1:1000,000) by Hamza (1997). Climate data, such as temperature, rainfall from (Sulaimani and Darbandixan metrological stations). Auxiliary data such as soil and vegetation map by Buringh (1960) and Hadad et al., (2009). Field information’s; photographs, measurements, observations, structural and stratigraphical data were collected during a long term field work along the basin. 1.5.2 Research Methods Study methods that used here can be broadly classified into two categories: Field work: field work is begun during Autumn in 2010 for 5 months in 18 field trips, using topographic map and satellite images to determine the boundary of the study area. The field works, were conducted along transverses selected across important segments of the study area. Field work was conducted through using topographic map (1:100,000) and (1:250,000) geological map, using compass, GPS in the field, beside taken photographs of different landforms, landscape and features in the study area. Office work: The second step which is involved the followings: 1. Data preparation:
Topographic maps of scale 1:20,000 were scanned and georefrenced in Arc GIS 9.3 software with acceptable minimum RMS, projected all map to Universal Transverse Mercator Projection (UTM) coordinate system, with WGS-84 datum, zone 38N. Creating mosaic for 13 top sheets by ERDAS imagine 8.2 software, then digitizing and editing all data wanted such as streams and springs.
Drainage network was generated from Digital Elevation Model (DEM) by using the Arc-hydro tool within Arc GIS software.
Contour lines in 50m intervals and hill shade were extracted automatically from the DEM by Spatial Analyst-surface analysis toolbar in Arc GIS.
Slope zones are created from DEM, slopes are classified for 5 class according to Zink classification (Zink, 1988-1989). 5
CHAPTER ONE
INTRODUCTION
Band combination of Landsat TM image was created in ERDAS Imagine 8.2 software, for visual interpretation of landforms and geological units.
2. Analysis and Interpretation: Treatment of collected data includes the following analyses:
Drainage basin analysis:
After digitizing stream networks according to Strahler system of ordering (Strahler, 1957), the attributes were assigned to create digital data base for Dewana basin. Some geometric characteristics such as length, area, elevation and perimeter for all streams and sub-basins are measured in GIS environment in order to calculate
morphometric
parameters such as: stream order (Nu), bifurcation ratio (Rb), stream length (Lu) , drainage density(D), stream frequency (Fs), texture ratio (T), elongation ratio (Re), form factor ratio (Rf), etc. (For more detail in chapter three). The linear aspects, areal aspects and relief aspects of drainage basin are studied using the methods of Horton (1932, 1945), Strahler (1957, 1964), Schumm (1956) and Miller (1953).
Geomorphic analysis:
Dewana basin had been geomorphologically analyzed and classified into geomorphic units and sub-units as assign by ITC (International Institute for Geo-Information Science and Earth Observation) and IGU (International Geographical Union) classification system. Medium scale geomorphological map of 1:150,000 was constructed (For more detail in chapter four).
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CHAPTER TWO
COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
CHAPTER TWO COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
2.1 Topography The study area located in the mountainous area so the topography characterized by rugged terrain and high gradient. The slope degree ranges between 2° and 74° (see chapter five). The Dewana basin is composed of elongated shape which is surrounded by high mountain ridges, from northestern part by Bararanan homoclinal ridge with elevation, reaches 1500 meters, and from northwestern side by Sagrma and Gwllan mountain with elevation exceeds 1800 meters. The central part of the study area composed of Kalosh mountain which it is elevation reaches 1400 meters (Fig. 2.1).
2.2 Geology 2.2.1 Tectonic and Structural Setting The Dewana basin is located near the southwestern margin of the High Folded Zone of the Zagros Orogenic Belt of northern Iraq (Fig. 2.2). It is represented by a low terrain located within a syncline that extends between Sagerma anticline and Baranan homoclinal ridge. The obvious basin is developed as a synclinal valley shape bounded by two anticlines and has NW – SE trend. The syncline is generally symmetrical, with SE plunge to NW of the studied area. The synclinal axis extends out of the area, in a slightly northwards direction. This structural setting would help in contributing accumulation of the surface and subsurface water, including those which are located to the north of Dewana perennial stream. Major structural trend follows the Zagros Folded Belt of NW-SE regional orientation. The geology of the basin is controlled by two major structural features which bound the basin from NE and SW. The first known as Darbandikhan anticline which bound the basin at NE, that diverges and splits in to the Baranan homocline ridge by Baranan back thrust fault (Ibrahim, 2009), that bound the basin at NE. Dip at this ridge ranges between (20 – 40) °.The second ridge known as Sagerma anticline which bounds the basin at SW, the eastern flank known as the Qara Dagh mountain and the western flank as the Sagerma mountain.
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COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
Figure 2.1: Digital Elevation Model of Dewana basin.
CHAPTER TWO
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CHAPTER TWO
COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
Figure 2.2: Tectonic map of northern Iraq showing location of the study area (after Jassim and Goff, 2006). Dip angle of strata in the flanks of Sagerma anticline could reach 70 degrees in some cases. These ridges are the surface expression of a main basement involved longitudinal fault named as Zagros Mountain Front Fault, which separates the High Folds Zone from the Low Folds Zone of the Zagros Orogenic Belt (Ibrahim, 2009) .The central part of the basin is controlled by the low terrain of the Qaradagh syncline which slopes southeast wards. This regional low terrain includes most of the Dewana basin area and is characterized by sub-horizontal strata of the clastic strata of Injana Formation. The only disturbing structural feature within this syncline is located in the middle of the basin, and represented by a local doubly plunging anticline known as the Kalosh anticline. Its axis trending
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CHAPTER TWO
COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
parallel to the major structural strike of the area, its cap rock consists of hard resistant limestone of the Pila Spi Formation. Other important structural features are; Transverse fault system, which dissect the main ridges developing gorges of significant valleys. These valleys represent the main catchment source to the Dewana basin. Some of these faults have displacement in the northern and southern part of Sagerma anticline. Reverse fault at Kalosh anticline is also reported (Stevanovic and Markovic, 2003). Streams networks controlled by main geological structure (plunge of the anticline in the north, ellipse shape of Kalosh anticline in the middle part of basin and homoclinal ridges of both (NE-SW) part (Fig. 2.3)
2.2.2 Stratigraphy The stratigraphic successions of the Dewana basin are dominated by the exposures of Tertiary rocks mainly of Pila Spi, Sinjar, Fatha, and Injana formations. The rock types exposed along the bounding ridges of the basin consists of hard erosion-resistant limestones of the Sinjar and Pila Spi formations. The flanking rocks are composed of the relatively soft Fatha Formation, and the extensive depression of the Dewana syncline is covered mainly by the clastic rocks of the Injana and Mukdadiyah formations (Figs. 2.4 and 2.5). Her in after is a brief review of the characters of the successions. 2.2.2.1 Kolosh Formation The Kolosh Formation sediments are of Paleocene- Late Eocene age (Bellen et al., 1959), but according to Lawa (2004) the formation is of Paleocene age. The formation represents the distal flysch sequence of the early Zagros foreland basin of northeast Iraq (Al-Qayim, 1994). Kolosh Formation represents the oldest rock unit exposed in the Dewana basin, where limited outcrop is exposed at the core of the Kalosh and Sagerma anticlines (Figs. 2.4 and 2.6). Only the upper part of the formation is exposed and consists of soft greenish gray silty shale alternating with medium to thin-bedded sandstone and lenses of conglomerate. The thickness of the exposed section may reach 50 meters. Due to its soft nature, it forms the deeply eroded valleys of the crestal part of the Kalosh Mountain (Fig. 2.7).
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Figure 2.3: Lineament map of Dewana basin (stream network based on digitizing 1:50000 scale topographic map).
CHAPTER TWO COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
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2.2.2.2 Sinjar Formation Sinjar Formation is believed to have an Upper Paleocene- Late Eocene age (Bellen, et al., 1959 and Lawa, 2004). The formation represents a reefal-shoal limestone of the shoaling basin, and thus alternate with the upper part of the Kolosh Formation (Buday, 1980). It is exposed at the core of the Kalosh mountain (Fig. 2.7), and crop out in the core of the sagerma anticline, and Baranan mountains.The formation also consists of buff to gray, thick to massive fossiliferous limestone (Figs. 2.4 and 2.6). Thickness of the formation is variable and reaches 50-60 meters. Due to its stratigraphic position over the soft strata of the Kolosh Formation. 2.2.2.3 Gercus Formation The age of Gercus Formation is Middle Eocene age and overlay the Sinjar Formation unconformablly (Bellen et al., 1959), The thickness of the formation varies between 255320m (Figs. 2.4 and 2.5). This formation is composed of alternatinf beds of mudstone, sandstone, shales, marlstones, marly limestone and conglomerate lenses or beds. These rocks are red to reddish color. Sandstones are well-bedded, fractured and are rich in iron content. The Gercus Formation forms steep dip and is dissected by drainage networks due to structural control. (Buday, 1980) believed that Gercus Formation deposited in abroad sinking molasses trough. 2.2.2.4 Pila Spi Formation The age of the Pila Spi Formation is considered to be Middle-Late Eocene (Bellen, et al., 1959). It often overlies the Gercus Formation unconformabilly. It has no significant exposures in the study area. The Pila Spi Formation is developed as elongated belts of high ridges surrounding the depression of the Dewana basin. Other area of exposure is in the flanks of the Kalosh anticline forming the carapace of the anticline (Fig. 2.4). It consists of whitish gray to milky white, hard, crystalline medium to thick bedded limestone and dolomitic limestone. Sometimes thin gray marl interlayers can be recognized (Fig. 2.8). Due to the high dip angle of these strata in the study area, they display frequent sliding phenomena over major slopes of the area.
12
Figure 2.4: Geological map of Dewana basin (modified after Ma’ala, 2008).
CHAPTER TWO COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
13
Figure 2.5: Geological cross section of Dewana basin passing through Kalosh anticline from A to B,(modified after Stevanovic and Markovic, 2003).
a.s.l .
CHAPTER TWO COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
14
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COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
Pila Spi Formation
Kolosh Formation Sinjar Formation
Figure 2.6: Kolosh and Sinjar formations in the core of Sagerma anticline.
Sinjar Formation Kolosh Formation
Figure 2.7: Kolosh and Sinjar formtains outcrops, in Kalosh anticline.
Figure 2.8: Pila Spi Formation in the NE limb of Sagerma anticline. 15
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COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
2.2.2.5 Fatha Formation (Lower Fars) The age of the Fatha Formation is considered to be Middle Miocene (Bellen et al., 1959). It usually overlays the Pila Spi Formation with unconformity marked by widely distributed conglomerate horizon known as “Basal Fars Conglomerate” (Buday, 1980). It flanks both ridges which surround the Dewana basin and thus forms an elongated belt of exposure. It often forms the lower slope below high limestone forming ridges, with gentle dip of 20-30 degrees. Other area of exposure is around of the Kalosh Mountain where it forms the middle slopes of the anticline (Fig. 2.4) .The rocks of the Fatha Formation in the studied area are limited, and rarely reach 50 meters. They consist of alternating reddish brown clay stone with limestone and gypsum (Fig. 2.9), the gypsum often occurs as local pockets or lenses (Fig. 2.10). 2.2.2.6 Injana Formation (Upper Fars) The Injana Formation is of Late Miocene in age (Bellen et al., 1959). The formation has extensive exposure in most of the synclinal trough of the Dewana basin (Fig. 2.4). The strata of the formation are generally horizontal to sub horizontal especially along the central part of the trough. Dipping strata of the formation can be seen flanking the surrounding ridges of the basin forming the toes of these ridges slopes. The Injana Formation consists of cyclic deposits. Each cycle consists of sandstone, siltstone and claystone, representing fining upwards cycles. The claystones are reddish brown in color. The sandstones are gray to brown, medium to coarse grained; hard, calcareous, usually form persistent ridges (Working Group, 2009 a). The siltstones are fine grained, soft to friable, clayey, thinly bedded and massive to thick bedded. It usually forms the lower part of each cycle. The claystones are soft, rarely silty and conchoidally fractured, occasionally papery. They form the shorter fore slope of the cuestas, which is capped by hard sandstone of the next cycle. The thickness of the claystones and siltstones units together ranges from 10 – 15 m (Working Group, 2009 a). The sandstones form 2 to 7 meters thick horizons. They display channeling and crossbedding structures indicating fluvial influence. Due to their hard nature and near the margins of the synclinal trough, they often form a successive protruding strike ridges forming a common ridge and valley landscape (Fig. 2.11). In other cases they form the protected cover of isolated cuestas. At the central part of the trough, horizontal sandstone beds forms the protection carapace of the remnant erosional hills (Fig. 2.12).
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COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
The thickness of the formation may reach 500 meters. The Injana Formation is overlain conformably by the Mukdadiyah Formation. 2.2.2.7 Mukdadiyah Formation (Lower Bakhtiari) The age of the formation is determined to be Pliocene (Bellen et al., 1959). It is exposed at the northwestern part of the basin at the central trough of the syncline (Fig. 2.4). The Mukdadiayh Formation exhibit cyclic depositional pattern of coarse clastic sequence. The sandstones are coarse grained, occasionally pebbly. Pebbles are (0.5 – 2) cm in size, subrounded to rounded, mainly of limestone, chert, and igneous and metamorphic rocks fragments (Fig. 2.13). They are fairly hard, massive to thickly bedded, cemented by calcareous cement, usually form persistant strike ridges .The siltstones are fine grained, clayey, thinly bedded, soft to friable, usually form the lower part of the slopes of each cycle (Working Group, 2009 a). The Mukdadiyah Formation is not fully exposed, however the sequence is fairly thick and may exceeds 250 meters. 2.2.2.8 Bi Hassan Formation (Upper Bakhtiari) The age of this formation is determined to be of Pliocene –pleistocene (Bellen et al., 1959). It is exposed at the northern part of the basin at the northern part of the central trough of the syncline (Figs. 2.4 and 2.5). The sequence is composed mainly of conglomerates, sandstone and siltstones. Conglomerates are massive, irregular bedded and coarse grained forming high ridges (Fig. 2.14).
Figure 2.9: Fatha Formation in the northestern limb of Sagerma anticline. 17
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COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
Figure 2.10: Gypsum lenses in Fatha Formation.
Figure 2.11: Successive protruding strike ridges forming a common ridge and valley landscape in Injana Formation, estern Kalosh anticline, center of Dewana basin.
Figure 2.12: Sandstone caped the siltstone in Injana Formation, near Astel village, west of Dewana basin. 18
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COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
Figure 2.13: Alternating sandstone and pebbly sandstone of Mukdadiyah Formation, Dewana basin.
Figure 2.14: Conglomerate in Bi Hassan Formation, north of Qara Dagh.
19
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COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
2.2.2.9 Quaternary Sediments The following types of Quaternary sediments were recognized in the Dewana basin covering older rock units in low areas and depressions. 2.2.2.9.1 River terraces Different levels of sandstones and conglomerate horizons are exposed along the major Dewana stream. Relation with older strata indicates their origin as old flooding episodes.These sediment are composed of different size, the detrital grain with diameters range from few millimeters to 20 cm, they are rounded shape, which means transported for long distance and the velocity of water was high (Aqrawi, 1990). Some of these horizons recognized along Dewana stream near Dewana village (Fig. 2.15). 2.2.2.9.2 Flood plain deposits (Holocene) These are low altitude horizons of sandy to silty terraces developed recently in more than one level, and next to the Dewana river course or its major tributaries, especially around mature meanders of the river during flooding seasons. Flood plain deposits consist of a mixture of coarse grains gravel and sand sediments plus fine grains clay and silt developed on the banks of the Dewana stream. They are partly lithified to lose sediment with flat upper surfaces (Fig. 2.16). 2.2.2.9.3 Valley fills sediments They are well developed in Dewana perennial stream as well as other major tributaries, with poorly cemented clastics. They are mainly of Holocene age. They are composed mainly of white limestone or gray sandstones, gravels filling main channel of the valleys, and are different in shape and size, most of them subrounded, with poorly cemented or loose sediment with fine grain matrix. 2.2.2.9.4 Slope sediments These are mixed clastic sediments of variable size and origin developed at slopes, foot hills, and slope toes especially at areas bounding ridges in the upper reaches of the basin. These sediments forms cone shape or wedge shape of mixed gravel and fine sediments. In some cases these cones are dissected by entrenching down channels.
21
CHAPTER TWO
COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
River terraces
Figure 2.15: River terraces along Dewana stream, near Dewana village.
Figure 2.16: Flood plain Deposit, near Kalosh village.
21
CHAPTER TWO
COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
2.3 Climate Climate is a part of the discipline that seeks to explain the form and distribution of landforms. Climate is a leading factor in determining chemical, mechanical, and biological weathering rates. Past and present climate have influenced the evolution of the landscape to present time. Climate impact on the dynamics of geomorphological and sedimentological systems (Vandenberghe, 2003). Climate has a significant impact on the formation of geomorphological phenomena on the ground surface, through the importance of the different structures and nature of lithology where the various climate elements affect type and speed of weathering and erosion.
2.3.1 The Paleoclimate Climate was changed few times during the Pleistocene. It is proved that north Iraq was subjected to periods with a much more humid climate alternated with much drier periods; these are called pluvial and interpluvial phases in the Pleistocene, respectively (Buringh, 1960). It could be noticed from river terrace levels, old drainage system, depth of gully systems, and older Holocene deposits, that the climate was changed. According to Buringh (1960), the climate was changed at least three times. During the pluvial phases of the Pleistocene, the climate was more humid than at the present time and the higher parts of the Zagros mountains were more permanently covered by snow and glaciers but during the inter-pluvial phases the climate was drier and warmer. Voute (1960), proved that creep, solifluction and slumping down slope in Sulaimaniyah valleys in the Zagros mountains indicate cold and very humid (rainy) climate while gullying and badland erosion down slope indicates semi- arid condition at this time. 2.3.2 Present Climate Cold winters, warm and dry summers are characteristic of the climate of the studied area. During summer, the studied area falls under the influence of mediterranean anticyclones and sub-tropical high pressure belts moving from the south-west to north. In the winter, the region is invaded by Mediterraneas cyclones moving east to north-east of the region. The autumn and spring are very short with mild temperatures (Aziz, 2001 in Stevanovic and Markovic, 2003). Because of this difference in seasons, the climate plays
22
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COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
big role in geomorphological activity in the studied area. According to the diagram of Peltiers (1950), the area under the influence of semi-arid climatic condition (Fig. 2.17). According to the data recorded by the Sulaimani metrological station for the years 2000-2010 (Tables 2.1 and 2.3) and Darbandikhan metrological station for the years 20072009 (Tables 2.2 and 2.4). The present climate is characterized by mean annual rainfall (657.37 and 455.33) mm and mean annual temperature (19.9 and 21.3)°C for Sulaimani and Darbandikhan stations respectively, mean annual evaporation (279577)mm. The mean wind speed was 2.3 m/sec. June, July and August are the months with the highest wind speeds and mean annual sunshine duration (8.12) hrs/year. From Tables (2.1and 2.2), it could be noticed that there is a great difference between seasons in amount of rainfall and air temperature. In winter season there is high precipitation, low air temperature and short sun shine duration while no or less amount of rainfall, high temperature and long sun shine duration during summer season. These differences in parameters between seasons will affect the geomorphologic process along the basin.
Figure 2.17: Morphogenetic region of Peltier’s (1950) diagram (red: climatic parameters Darbandikhan station, blue: climatic parameter Sulaimani station).
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COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
Table 2.1: Average maximum and minimum temperature and mean annual temperature °C in Sulaymani station for years (2000-2010) (Sulaimani Metrological Directorate).
Autum Summer Springe Winter
Seasons
Monthly Minmum Maximum Temperature Average Months Temperature Temperature range °C Temperature °C °C °C December 5.2 13.5 9.4 8.3 January 2.7 10.6 6.6 7.9 3.7 12.3 8 8.6 February March 7.1 17.6 12.7 10.5 April 11.8 22.2 17 10.4 May 18 29.5 23.7 11.5 June 23.7 35.8 29.8 12.1 July 26.9 39.4 33.2 12.5 26.6 39.6 33.1 13 August September 22.2 34.6 28.4 12.4 October 16.5 28.3 22.4 11.8 November 9.3 19.1 14.4 9.8 Annual 14.5 25.2 19.9 10.7
Table 2.2: Average maximum and minimum temperature and mean annual temperature °C in Darbandikhan station for years (2007-2009) (Sulaimani Metrological Directorate).
Autumn Summer Springe Winter
Minmum Maximum Monthly Temperature Seasons Months Temperature Temperature Average range °C °C °C Temperature December January February March April May June July August September October November Annual
6.0 2.0 4.8 8.4 12.8 19.8 25.9 28.6 27.3 23.5 16.9 10.0 15.5
14.6 11.7 14.6 20.1 24.7 32.7 39.3 42.3 42.2 34.6 30.3 20.1 27.3 24
10.3 4.5 9.7 14.3 18.8 26.2 32.6 35.1 34.8 30.4 23.7 15.1 21.3
8.6 9.7 9.8 11.7 11.9 12.8 13.4 13.7 14.9 11.1 13.4 10.1 11.8
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COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
Table 2.3: Average monthly and mean annual rainfall in (mm) over Sulaimani metrological station for years (2000-2010) (Sulaimani Metrological Directorate). Winter
Seasons Monthes Rain fall (mm)
Spring
December January February March April
Summer May
Jun
Autumn
July August September October November
114.02 132.17 127.21 77.88 80.38 34.16 0.24 0.00
0.02
1.73
34.09
55.47
Mean annual 657.37
Table 2.4: Average monthly and mean annual rainfall in (mm) over Darbandikhan metrological station for years (2007-2009) (Sulaimani Metrological Directorate). Winter
Seasons Monthes Rain fall (mm)
Spring
December January February March April
29.80
Summer May
Jun
Autumn
July August September October November
65.87 106.03 44.63 85.27 8.43 0.97 0.00 0.00
3.50
41.80
69.03
Mean annual 455.33
2.4 Soil Buringh (1960) has studied and classified Iraqi soils, and then followed by (Hadad et al., 2009) who had modified the soil classification of Sulaimani soils according to the modern classification system (soil taxonomy). These classes are present in the study area and shown in figure (2.18): 2.4.1 Vertisols These soils are rich in clay minerals more than (30%) until 50 cm of depth. They consist of silt loam mixed with some gravels, grading into brown silt loam at 14 cm, with lime accumulation beginning at a depth of 30 cm. This soil has been named by Buringh as brown soil. This soil covered Qaradagh Syncline in the study area. 2.4.2 Aridisols These soils are of arid and semi-arid environments. Salinization is important soil forming processes acting in these soils which lead to inhibition of root penetration in soil (Hadad et al., 2009). It consists of rough, broken, stony and mountainous land and classified as rough broken and stony land. According to Buringh (1960) these types are distributed in ridges and foot slopes surrounding the Dewana basin and over Kalosh mountain (Fig. 2.18).
25
Figure 2.18: Distributions of soil classes in the study area (compiled from Buring, 1960 and Hadad et al., 2009).
CHAPTER TWO COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
2.5 Vegetation Cover
26
CHAPTER TWO
COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
Vegetations are the product of reaction of climate, water and soil type; they determine type, growth and density of vegetation cover. Depending on the type of climate of the study area is semi-Arid, covered by different type of vegetation such as trees, shrubs, crops, and herb. Because most of the study area is badland so vegetation covers are not dense and scattered in the area. The vegetation has a great effect on geomorphologic process, especially in erosion process, that increasing in vegetation cover will lead to decrease erosion processes (rill erosion, gully erosion, soil creep), while sometimes the roots of the trees play a role in acceleration of the mechanical erosion. Generally the study area is covered by four types of vegetation covers these are: 2.5.1 Forest Trees These types of vegetation are common in the study area. The size and the density of these trees depend on many factors, including their position relative to the winds that bring rain and to the sun direction. They are less dense on the western slopes and south-western front of the wind from the mountains of Sagerma and more intense on the slopes of the northeast of them. Running waters as well as springs have a great impact on growth of trees density and distribution, such as crowded trees and extending along the course of those streams and springs, and the gradient has also an effect on trees, that less trees are found on the steep slopes, that lead to exposing the soil and facilitate the process of erosion by running water and snow. Oak trees represent the most common type in those areas, they represent %95 of natural trees in this area (Fig. 2.19).The remaining %5 are represented by Turpentine tree, Iron wood, etc. (Jabbar, 2007). Oak trees grow on elevated area generally between (600 1800 m) above sea level. 2.5.2 Shrubs Generally shrubs grow in the study area, some of them are short of papers leaves such as Olender and Red raspberry, and some of them are forklift such as Figs and Sumaq (Jabbar, 2007).We find some of these types near the water or grow away from it like the rest of the bushes, and another are found in groups such as chaste tree. 2.5.3 Vegetation along rivers Also called Bush trees, it grows on the banks of rivers in the steppe, as well as in the valleys. They extend along the banks of major streams like Cane plant of all types, which are locally called Qamish (Jabbar, 2007) (Fig. 2.20). 27
CHAPTER TWO
COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
2.5.4 Grasses herbs and polychaetes In the study area some type of grasses and herbs are grown during the spring and continue their life during the summer time. Some of them grow during spring and summer then dry up and die in the end like: Oats, Barley and Rye which grows in the humid parts of the region (Jabbar, 2007). While some of them are toxic weeds and others represent medicinal herbs.
Figure 2.19: Oak trees in the Sagrma anticline NW of study area
Figure 2.20: Dense bushes along Dewana Stream.
2.6 Water Recourses Because the study area hase a mountaneous charecters, the relief and the trends of mountain ridges controls the limit and quantity of precipitations, as it determine the direction of precipitation and flow direction. Also the slope direction in the area determines 28
CHAPTER TWO
COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
the nature and direction of flow water. Because the semi- arid climate of the area, the ground remains moist and fed by water for a long period of over eight months. It does not dry up in some place throughout the year. Permeable soil type (gravel, cracks and fractures as spreading in the region ), act to reduce the surface runoff, as well as the natural vegetation or crops of the cultivated area, especially in dense vegetation cover (areas which the interwoven grass and polychaetes). All of these factors will help in recharging ground water storage by additional source renewed annually. The exploitation of the human use of water resource in the region is a key factor in controlling the amount of water. A water resource in study area includes: 2.6.1 Surface water Surface water can be classified in two types: intermittent and ephemeral streams. These are related to the terms influent and effluent. The first are those in which the stream feeds the ground water as compared to effluent in which the stream receives water from it (Gordon et al., 2004). There is no clear demarcation between surface runoff and an ephemeral stream on the climate, geology and vegetation in the studied area. It could be seen that the surface water is basically intermittent for some parts and others are perennial. Dewana Stream is considered as perennial stream. So total surface water in the study area is represented by intermittent and perennial streams in which snow and rain represent its source of recharge. Surface water is responsible for carving and shaping some landscapes in the study area because water is the most active process. Most features are formed by water erosion or deposition, gully, rills, channel and karst are most developed features by surface waters. Figure (3.1) shows stream network of the study area, from the springs that are coming from Pila Spi, Bi Hassan, Injana and Fatha formations, figure (2.21) show location of springs in the study area, for example the minimum discharge of Astel xwaro spring which is located at northwestern of Dewana basin is 87 L/sec and maximum discharge is 554 L/sec (Directory of Irrigation and Water Resources/Sulaimani).
29
Figure 2. 21: Location of wells and springs related to the villages in Dewana basin (wells from Ground water directorate/Sulaimani, springs from digitizing 1:20,000 topographic maps).
CHAPTER TWO COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
31
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COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
The Dewana stream peak discharge is 500m 3/sec(Working group, 2009 b) These major streams in the study area that feed Dewana basin are; Chamy Darawyan ,Wady Kany Gora ,Wady Loghmaka, Wady Jafaran. In N part of basin, Chamy Dary Zard ,Chamy Wshk ,Wady Hazrkany, in NW of basin,Chamy Gora in NE of basin, Chamy Wara Qarawax in SW part of basin, Chamy Dewana )(see chapter three ) 2.6.2 Ground water The ground water represents the second water resource in the studied area; rain and snow compose its main recharging sources. According to nature of rocks and its topography the studied area contains amount of ground water that can be extracted naturally or artificially. Several parameters affect in forming and detecting its type and distribution, like climate, topography and type of rock and their permeability. Air temperature, wind speed, precipitation (type and amount), and humidity all together have great influence in determining amount of the ground water. There is a great relation between ground water and topography, convex topography (hill and mountain) bonding concave topography (valley and plain), lead to accumulation of part of mountain water beneath valley and plain (Jabbar, 2007). Aquifers in the study area are of the type unconfined aquifers, among which Sinjar Formation has large area for collection water more than Pila Spi, Fatha, Injana and Quternary deposits respectively in the susceptibility in water saving . Pila Spi and Sinjar Formations have fissured and karstic aquifers and inter granular aquifer of Muqdadya and Bi Hassan, Formations (Lawa, 2003). Different types of ground water are present in the study area which are:
2.6.2.1 Springs Many springs in the study area (especially in the mountain foot) slope are of fractures, and vallyes types, where water tables intersect the earth’s surface. The distribution will depend on amount of rainfall, permeability of rocks, rock slopes and erosional factor that will help in removing upper bed and appearing springs into the earth surface, as well as faults and weak zones have a great affects of the springs locations. Around (44) springs are existing in the study area (based on 1:20,000 topographic map) most of them are concentrated in foot slopes of the main ridges around the basin. Astel spring is an important discharge point, which is located at the NW plunge of Kalosh anticline with high discharge, from Pila Spi aquifer (Fig. 2.21). 31
CHAPTER TWO
COMPONENTS OF GEOMORPHOLOGICAL ENVIRONMENT
2.6.2.2 Wells People may be forced to extract ground water due to the lack of rain and surface water for using it in different purposes (irrigation, human consumption and animals). Since ground water in the area exist, people digged wells specially in synclinal trough, which help in collecting water from surrounding ridges. From figure (2.21) appears that each village has one or more wells. For example in Swerraw village, they drilled an artisan well with more than 25 l/s discharge, which is from Pila Spi fissured and karstified aquifer. Regarding those wells that are drilled in Muqdadya and Bi Hassan Formation (inter granular aquifer) it’s of very low discharge due to the unconfined condition of the aquifers. Only Bakhan well of good discharge, several wells drilled in Awi Hami Karam and others villeges are of very low discharge (Lawa, 2003).
32
CHAPTER THREE
DRAINAGE BASIN ANALYSIS
CHAPTER THREE DRAINAGE BASIN ANALYSIS
3.1 Dewana Basin Dewana basin includes the Dewana perennial stream and its main tributaries passing along the elongated basin, which covers an area of (606 km2) from upper Darawyan village to Diyala river. Its boundaries are surrounded by many mountains, which separate it from the surrounding basins; Baranan range located to the NE of the basin that separates Dewana basin from Tanjero basin and Sagrma mountain with Gullan mountain separate it from Awa Spy basin. While in the north it is separated from Basara basin by Barzy Dolan mountain, and from the south all channels drain to Diyala river (Fig. 3.1). Kalosh Mountain is located in the middle of the Dewana basin. The maximum altitude of the basin is 1878 m, above sea level at Qala Gila Nawa peak, while the minimum altitude is 365m, above sea level near Dewana stream before it reaches Diyala river. The basin area is covered by several carbonate and clastic deposits of tertiary sequence. Since carbonate rocks are dominant in the basin, a considerable amount of surface water recharges the aquifers. All the water courses of this basin flow eventually toward the Diala river. Dewana stream flows through tens of villages and farms, which makes it an important source for water need for agricultural project and encourage the planning of Dewana dam and reservoir downstream. The Dewana basin is delineated from surrounding basins based on location of water divide line by using 30m grid DEM and vector stream network following (Dillabaugh, 2002; Lin et al., 2005; Korkalainen et al., 2007; Mendas, 2010 ;Graves, 2001 and Djokic, 2008) by using Arc hydro tool (Dartiguenave,2007) and Spatial Analyst extension following (Johnson, 2009) in Arc GIS 9.3. This model is calibrated by using topographic maps of different scales. Two sub-basins were extracted from Dewana basin to show local variation in these two sub-basins, depending on their major tributaries of Dewana stream and their different geological setting. It is divided by water divide line into Chamy Gora and Chamy Wara Qarawagh basins. The sub-basins are named based on the local name of streams. The coverage areas of these basins are 99 and 131 Km2 respectively (Fig. 3.1).
33
Figure 3.1: Dewana basin drainage network and sub-basins (Stream from digitizing 1:50000 scale topographic map).
CHAPTER THREE DRAINAGE BASIN ANALYSIS
34
CHAPTER THREE
DRAINAGE BASIN ANALYSIS
3.2 Network Analysis The shape of the stream network reflects the hydrologic processes that prevail in the area and in turn determines the hydrological efficiency of the basin. Stream network in each area depends on topography, rock nature, structural position and tectonics of that area (Thornbury, 1954). The drainage network of the Dewana basin has been automatically extracted from 30m grid DEM according to Lin et al. (2005) and also digitized from topographic map of scale 1:20,000 and 1:50000. A variety of hydromorphometric parameters have been measured, such as drainage basin length, perimeter, and drainage area in GIS environment as an integrated watershed analysis following (Dietz, 2000), (Yusuf et al., 2011).Two different scales are chosen for detail network analysis of Chamy Gawra sub-basin and Chamy Wara Qarawagh sub-basin in figure (3.2 and 3.3). There is a great difference between these two scales because of scale variation, especially in stream number, length of streams and stream ordering, which affect morphometric parameters such as bifurcation ratio, drainage density and so on. This has great significance on geomorphological interpretations, therefore, it is recommended for more detail work a larger scale maps, should be used. The prominent drainage basin under the study covers the network of the main stream, which is Dewana basin. The Dewana main channel starts from the Tavan village; in the northwestern part of the basin and joins the other main tributaries from northeastern part of the basin and northwestern part behind Kalosh Mountain. The name of main branches that collect water from their catchment areas are: Chamy Darawyan, Wady Kany Gora, Wady Loghmaka, Wady Jafaran, in the northern part of the basin, Chamy Dary Zard, Chamy Wshk, Wady Hazr kany in the northwestern part of the basin, Chamy Gora in the northeastern part of basin, and Chamy Wara Qarawagh in the southwestern part of the basin (Fig. 3.1). The general flow direction of Dewana stream is parallel to the main direction of the structures in the area. It is subsequent type, where the major flow lines coincide with the direction of formations boundary (strike line), their tributaries are consequent, obseqeuent and inseqeuent types, as shown in figure (3.4).
35
Figure 3.2: Chamy Gora networks prepared from different scales A. 1:20,000, B. 1:50,000
CHAPTER THREE DRAINAGE BASIN ANALYSIS
36
Figure 3.3: Chamy Wara Qarawagh network prepared from different scale A. 1:20,000, B. 1:50,000.
CHAPTER THREE DRAINAGE BASIN ANALYSIS
37
Figure 3.4: Drainage network and their relation to the bed attitude.
CHAPTER THREE DRAINAGE BASIN ANALYSIS
38
CHAPTER THREE
DRAINAGE BASIN ANALYSIS
The Drainage system shows several patterns in the studied area (Fig. 3.5), which in turn reflect mainly structural or lithologic controls of the underlying rocks (Al-Saud, 2009). From drainage pattern the type of landform and its morphometry can be indicated (Burberry et al., 2008). Dendritic drainage pattern is the most common type in the studied area and it is characterized by a tree like branching system in which the tributaries join the gently curving main stream at acute angle. The occurrence of this drainage system indicates homogeneous uniform soil and rock materials and it is typified by the landforms of soft sedimentary rocks (Way, 1973). It can be seen in the southwestern part of study area in special(Figs. 3.5 and 3.6) Sub-parallel drainage system is developed on a homogeneous, gently, uniformly sloping surfaces who’s the main collector indicate a fault or fracture, tributary join the main stream approximately at same angle (Way, 1973).In the studied area this pattern can be seen in the southwestern side of Baranan Range(Figs. 3.5 and 3.7). Sub trellis pattern is modified dendritc form, with parallel tributaries and short parallel tributaries occurring at right angles. This pattern indicates bed rock structure and alternating hard and weak roks; unusually indicates tilted, inter bedded, sedimentary rock in which the main channel flows parallel to the strike of the beds (Way, 1973).This pattern can be seen in Qara Dagh Anticline, where the rocks are affected hard by structural deformation and fractaring(Fig 3.5). Radial drainage pattern, which is a radiating network of almost diverging channels flowing away from a central elevated area .A major collector stream is usually found in a curvilinear alignment around the bottom of the elevated topographic texture, isolated hills, dome like landforms exhibit this type of drainage network (Way, 1973), this pattern can be seen in the middle of basin at the boundary of Kalosh mountain (Fig. 3.5).
39
Figure 3.5: Different types of drainage patterns of Dewana Basin.
CHAPTER THREE DRAINAGE BASIN ANALYSIS
41
CHAPTER THREE
DRAINAGE BASIN ANALYSIS
Figure 3.6: Satellite image showing dendritic drainage pattern in northern part of Dewana basin.
Figure 3.7: Satellite image showing Sub parallel drainage pattern in the southwestern side of Baranan ridge, Dewana basin. 41
CHAPTER THREE
DRAINAGE BASIN ANALYSIS
3.3 Morphometric Analysis The drainage basin is the fundamental unit of the fluvial landscapes, which has been the focus of researches aimed at understanding the geometric characteristics of the master channel and its tributary network. This geometric character of a drainage basin is referred to as the basin morphometry (Ritter et al., 2002). A drainage basin is not a simple linear or areal (spatial) unit, but it is the dynamic system which is engaged in transfer of energy and sediments from one point to other in the whole course. The drainage basin acts as an open dynamic system (Howard, 1965). Direct measurement of the inputs and outputs in the drainage system are most complicated, but the nature of the measurement of various dimentional and dimensionless parameter are conspicuous. Prior to 1945 geographic studies were concentrated mainly on qualitative and deductive aspects. The new era of quantitative analysis was initiated by Horton (1945) who first applied the techniques of quantitative analysis of the drainage basins. Following Horton's led; Schumm(1956), Strahler (1957) and others developed quantitative methods by adding new parameters and investigating regional variations in morphology in a wide range of geologic and climatic environments. In the present study of the Dewana basin, numerical quantitative analysis (morphometry) have been applied to describe the linear, areal, and relief characteristics of the watershed (Table 3.1) to infer the interrelation between various parameters of drainage basin and their impact on the development of the evolution of the stage of the basin. Morphometric analysis of drainage basins thus provides not only an elegant description of the landscape, but also serve as a powerful means of comparing the form and process of drainage basins that may be widely separated in space and time (Ajibade et al., 2010). Estimation of two types of measurement had shared out: First type is a linear scale measurement, like: length of streams of any order, length of basin perimeter, relief and other measurement that result in a tedious and time consuming process. In order to mechanize this process and time saving, an attempt has been made to make use of digitized map by application of GIS technology according to Dinesh (2008) and Christopher et al., (2010). The second type consists of dimensionless numbers often derived as ratio of length parameters like: length ratio, bifurcation ratio, relief ratio.etc.). Table 3.1 shows the most commonly used linear, areal, relief equations.
42
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Table 3.1: Formula adopted for the computation of morphometric parameters of Dewana basin. Sl.N Mophrometric Parameters Formula o. linear Morphometry 1 Stream order(u) Hierarchical rank 2 Stream length (Lu) Length of the stream 3 Mean stream length (Lsm) Lsm =∑Lu / Nu Where, Lsm = Mean stream length ∑ Lu = Total stream length of order 'u' Nu = Total no. of stream segments of order 'u' 4 Stream length ratio (RL)
5 Bifurcation ratio (Rb)
RL = Lu / Lu – 1 Where, RL = Stream length ratio Lu = The total stream length of the order 'u' Lu – 1 = The total stream length of its next lower order Rb = Nu / Nu + 1 Where, Rb = Bifurcation ratio Nu = Total no. of stream segments of order 'u' Nu + 1 = Number of segments of the next higher
6 Mean bifurcation ratio (Rbm) Rbm = ∑Rb/Total No. of orders where, Rbm=Average of bifurcation ratios of all orders 7 Length of over land flow(Lo) Lo = 1/ 2 D Where, Lo = Length of overland flow D = Drainage density 8 Basin length (Lb) 9 Basin Perimeter (p) 10 Drainage Area (A) 11 Drainage Density (D)
12 Stream Frequency (Fs)
13 Drainage texture (T)
14 Circularity Ratio (Rc)
15 Elongation Ratio (Re)
16 Form Factor (Rf)
17 Basin relief (H) 18 Relief ratio (Rh) 19 Ruggedness number (Rn)
length of the basin length of basin boundary Areal Morphometry Area of drainage basin D = Lu / A Where, D = Drainage density Lu = Total stream length of all orders A = Area of the basin (km²) Fs = Nu / A Fs = Stream frequency Nu = Total no. of streams of all orders A = Area of the basin (km2) T = Nu / P Where, T= Drainage texture Nu = Total no. of streams of all orders P = Perimeter (km) Rc = 4 * Pi * A / P² Where, Rc = Circularity ratio Pi = 'Pi' value i.e., 3.14 A = Area of the basin (km2) P² = Square of the perimeter (km) Re = 2 √(A /Pi²)/ Lb Where, Re = Elongation ratio A = Area of the basin (km2) Pi = 'Pi' value i.e., 3.14 Lb = Basin length Rf = A /Lb² Where, A = Area of the basin (km2) Lb² = Square of basin length Relief Morphometry Hmaxi-H mini where H=elevation (m) Rh=H/Lb where H=Basin relief , Lb=Basin length Rn=H*D where H=Basin relief, D=Drainage density
43
Reference Strahler (1945) Horton (1945)
Strahler (1964)
Horton (1945)
Schumm (1956)
Strahler (1957)
Horton (1945) Schumm(1956) Smith (1950)
Horton (1932)
Horton (1945)
Horton(1945)
Miller (1953)
Schumm(1956)
Horton (1932)
Bhawan(1998) Schumm(1956) Verstappen(1983)
CHAPTER THREE
DRAINAGE BASIN ANALYSIS
The morphometric analysis of Dewana Basin has been carried out using the digitized stream network from topographic maps of 1:50,000 and 1:20,000 scale and Quick-bird satellite image. The measurement of morphometric parameters are presented in the following sections can be broadly classified into three categories: linear morphometric relationship, areal morphometric relationships, and relief morphometric relationships. 3.3.1 Linear Morphometric Relationship The establishments of stream ordering led by Horton (1945) to realize that certain linear parameters of the basin are proportionately related to stream order and that these could be expressed as basic relationships of the drainage composition (Ritter et al., 2002). Below are the measured morphometric parameters and interpretation.
Basin length (L) This is the straight line from the mouth of the basin to the farthest point on the basin
perimeter (Schumm, 1956)(Table 3.1). In this study the farthest point on the ridge on basin perimeter is determined visually and the calculation of the distance between this point and the mouth is done by measure tool in Arc GIS 9.3 environment. The Dewana basin length is 50 Km but for Chamy Gora and Chamy Wara sub basins the length are equal to, 17 and 18 Km, respectively (Table3.2).
Stream Orders (u) Horton (1945) and Schumm (1956) and others discussed the relationship between
stream order and factors composing a drainage basin. The most important results are as follows: As stream order increases, the number and the mean gradient of streams decrease in an inverse geometric ratio. As stream order increases, the mean length of streams and the mean area of drainage basin increase. The shortest and the steepest streams have the smallest drainage basins. In the present work Strahler’s stream ordering system is followed because it is convenient in computing various parameters and variables of the drainage basin. He defined each finger-tip channel as a segment of the first order, at the junction of any two first order segments, channel of the second order is produced and extends down to the point where it joins another second order channel, upon which a segment of third order
44
CHAPTER THREE
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resulted, and so forth. However, should a segment of the first order joint a second or third order segment, no increase in order occur at that point of junction (Strahler, 1975). The channel segment is ranked according to Strahler’s stream ordering system in two different scales using Arc GIS 9.3 software. The main Dewana basin represents a 6th order drainage basin according to 1:50,000 scale on digital topographic map, and 7th order according to 1:20,000 scale on paper topographic map. This difference in the number of order is due to the difference in scale of detailed mapping between the two maps. The ordering of the network is presented with different color for each order. The sub basin ordering are: Chamy Gora and Chamy Wara Qarawagh sub basin falls in 4 and 5 orders ,respectively on scale 1:50,000 and 6 orders stream on scale 1:20,000 (Figs. 3.3, 3.2)(Table 3.2) .
Stream Number (Nu) The count of stream channels in each order is known as “stream numbers”. According
to Horton,(1945) law of stream numbers expresses the relation between the number of streams of a given order and the stream order in terms of an inverse geometric series. A total of 1116 stream segments were identified, among them 181 and 264 are located in Chamy Gora and Chamy Wara Qarawagh sub basins, respectively in scale 1:50,000 and 931 and 1316 in Chamy Gora and Chamy Wara Qarawagh sub basin, respectively in scale 1:20,000 (Table 3.2) (Figs. 3.2 and 3.3) The differences in the stream number are expressing morphometic relation such as bifurcation ratio, length ratio, etc. In this study, we chose 1:50,000 scale for all parameters because there is no much difference and digitizing on scale 1:20,000 needs more time, so we just digitized Chamy Gora and Chamy Wara Qarawagh basin for comparison. According to Horton’s method the relationship between the stream order and the stream number is represented graphically. The stream order is shown on ordinary scale and stream number on log scale. It shows straight line that indicates a progressive decrease in the number of streams as there is progressive increase in the stream order. Thus the relationship between the two parameters behaves in harmony with the law of stream order and stream number of Horton (1945) (Fig. 3.8). This relationship between the two parameters reveals that the streams in all sub basins and whole basin are gradually entering the maturarity stage (Ghareeb, 1983).
45
CHAPTER THREE
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Table 3.2: Linear Morphometric parameters of Dewana Basin and sub-basins based on maps of scale 1:50,000.
Stream Name of order basin (U) 1
Stream Length of Stream Bifurcati Mean Stream Stream mean Cumilative Basin over land number on ratio bifurcation length length length mean perimeter flow in (Nu) (Rb) ratio (Rbm) in Km(Lu) ratio (RL) (L¯u) in length in Km(P) Km Km 134
3.622
147.103
1.098
1.098
1.393
2.490
2.789
5.279
18.186
23.465
1.046
1.046
1.126
2.172
3.057
5.230
2.437
7.666
16.672
24.339
1.072
1.072
1.345
2.417
2.687
5.104
5.459
10.563
26.257
36.821
24.238
61.059
Basin length (Lb) in Km
Chamy Gora
0.350 2
37
4.111
51.526 0.452
3 4
9
9.000
5.578
23.301 0.780
1
18.186
Total
181
240.115
1
198
0.206
45
17
0.204
48
18
0.266
132
50
Whole Dewana basin
Chamy Wara Qarawagh
5
3.960
207.104 0.272
2
50
4.167
56.312 0.652
3 4
12 3
4.000
3.782
3.000
36.688 0.199 7.310 2.281
5
1
16.672
Total
264
324.087
1
841
3.912
902.261
2
215
4.300
289.205
0.321 0.465 3
50
7.143
4
7
3.500
5
2
2.000
134.372 4.171
0.284 38.215 1.374 52.515 0.462
6
1
24.238
Total
1116
1440.806
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CHAPTER THREE
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1000
Chamy Gora Subbasin 100 Stream numbers
Chamy Wara Qarawagh Subbasin
Dewana whole basin
10
1 0
1
2 Stream 3 orders
4
5
6
Figure 3.8: Showing relationships between stream order and stream numbers of studied basin and two sub basins.
Bifurcation Ratio (Rb) The term bifurcation ratio is used to express the “ratio of number of streams of any
given order to the number of streams in next higher order” (Schumm, 1956). Strahler, (1957) had demonstrated that the bifurcation ratio shows a small range of variation for different regions or for different dominate environments. The irregularities of the bifurcation ratio from one order to the next order are mainly dependent upon the lithological and geological development of the drainage basin (Rudraiah et al., 2008). Bifurcation ratio characteristically that ranges between 3.0 and 5.0 with value of 2 as minimum for basin in which the geologic structures do not distort the drainage pattern (Christopher et al., 2010), bifurcation ratios that ranges between 3 and 4 indicate universal range of maturally dissected drainage basins(Subramanyan,1974). High Rb is due to the effect of local geological structure is dominant, but the shape of basin also has important effect, Rb tends to be high value when the shape is elongated (Verstappen,1983). In the present work the bifurcation ratios and mean bifurcation ratios are calculated for all studied sub basins (Table 3.2). The bifurcation ratio of Chamy Wara Qarawagh sub basin lie between 3 and 4.1, but the exception are in in Chamy Gora sub basin lie between 47
CHAPTER THREE
DRAINAGE BASIN ANALYSIS
3.622 and 9, the bifurcation ratio for hole dewana basin is range between 2 to 7.1. These increasing in Rb value in 3/4 orders may reflect tectonic control (neo-tectonic) in the northern part of the basin (Fig. 3.1)
Stream Length (Lu) The stream length is one of the most significant hydrological features of the basin; as it
reveals surface runoff characteristic of the areas. Generally the total length of stream segments is maximum in first order streams and decreases as stream order increases (Christopher et al., 2010). The total lengths of streams of each order are measured by a measuring tool in Arc GIS 9.3 environments and some of them are verified by curvemeter manually and saved in attribute table, by calculating geometry option, the length of all segments can be obtained. The existence of high Lu value is due to structural complexity, high relief and impermeable bedrock (Reddy et al., 2004). From table 3.2, it can be noticed that the total lengths of streams (Lu) for a selected basin range between 240.115 to 1440.806 km, that have direct relation with the basin area,indicating increase in stream length with increasing of basin area, because the action of erosin and drainage growing. It could be noted that the 1st order segment is shorter than the higher order, because lower order stream flow over slopping area and as stream order increase, slope become gentler and the streams almost lay on plain surface. In the table (3.2) it can be seen that the total length of 4 th order streams in the basins is much less than the 5th orders the reason is that due to accelerated headward erosion along zones of structural weakness and the higher order stream collect water from lower orders stream all around the basin which extends their length over most of the basin so the total length of higher order streams is more than that of normal.
Mean stream length (L-u) Mean length of a stream segment of order u is a dimensional property revealing the
characteristic size of components of drainage network and its contributing basin surface. To obtain the mean length L-u of order u, the total cumulative length of the ‘u’ order stream is divided by the number of segments Nu of that order (Chow,1964), it is observed that mean stream length increases with the increase in the stream order (Table 3.2). Mean stream length is plotted on log scale versus stream orders on ordinary scale (Fig. 3.9).The plot shows the increasing trend in average length with increasing order following Horton’s 48
CHAPTER THREE
DRAINAGE BASIN ANALYSIS
law of stream length, which states that “The average length of streams of different orders in a drainage basin tends closely to approximate a direct geometric series in which the first term is the average length of streams of the first order”.
length
100.000
10.000 stream
Chamy Gora sub basin
Mean
Chamy Wara Qarawagh sub basin Dewana whole basin
1.000 1
2 Stream 3 orders
4
5
6
Figure 3.9: Relationship between mean stream length and stream order and whole basin.
Length of over land flow (Lo) It is the length of flow of water over the ground before it becomes concentrated into
definite stream channels (Table 3.1). Length of over land flow is approximately equal to half the reciprocal of the drainage density (Horton, 1945). Overland flow is sustained by a relatively thin layer of surface detention, these disappear quickly often in few minutesthrough absorption by soil or infiltration after rain ends. This factor basically relates inversely to the average slope of channel and is quite synonymous with the length of the sheet flow to the large degree. From table 3.2, it could be noticed that the length of overland flow for Chamy Gora and Chamy Wara Qarawagh sub basins are 0.206 and 0.204 km, respectively, but for whole Dewana basin is 0.266 km it mean that the rain water has to run over these distances before getting concentrated in stream channels.
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CHAPTER THREE
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Stream Length Ratio (RL) This is the ratio of length Lu of segments of order u to length of segments of the next
lower order Lu-1 (Table3.1). Horton (1945) stipulated that RL tend to be constant throughout the successive orders of a watershed. Its value is normally between 1.5 and 3.5, in natural drainage networks (Bhawan, 1998). From Table 3.2, it could be noticed that most of the length ratio values are almost less than 1, except in some orders, this is due to lithological and topographic control on the different parts of the basin.
Basin perimeter (P) Basin perimeter is the total length of the basin boundary to length measured along the
divide between basins. It was emphasized by Smith (1950) and may be used as an indicator of basin size and shape, the perimeter of whole Dewana basin, Chamy Gora and Chamy Wara Qarawagh sub basins equal to 132, 45 and 48 Km, respectively (Table 3.2).
3.3.2 Areal Morphometric Relationship
Drainage Area (A) Drainage area is defined as the collecting area from which water would go to a stream
or river. The boundary of the area is determined by ridge separating water flowing in opposite directions (Bhawan, 1998). With increasing the basin size the peak flow decreases and hydrograph tends to be smoother if compare to smaller size (Verstappen, 1983). In this study, the catchment area has been delineated on 1:50,000 topographic map with field checks and verified by DEM analyzing. The areas of basins are measured by Arc GIS measuring tool. The area of whole Dewan basin, Chamy Gora and Chamy Wara Qarawagh sub basins are 606, 99 and 131 km2, respectively (Table 3.3).
Drainage Density (D) The drainage density is the average length of stream within the basin per unit area
(Horton, 1945),(Table 3.1).Beside rainfall and relief in determining drainage density there are three important factors, these are; infiltration –capacity of the soil or terrain and initial resistance of the terrain to erosion which means rock type and climatic condition. Horton (1932) suggested that the low drainage density indicates that the basin is highly permeable subsoil with thick vegetative cover and where relief is low. High drainage density is the 51
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resultant of weak or impermeable subsurface material, sparse vegetation and mountainous relief. Heavy rain fall, annual and seasonal are largely responsible for high value of D (Aqrawi, 1990). Low drainage density leads to coarse drainage texture while high drainage density leads to fine drainage texture (Strahler, 1964). The low D indicates of high permeable surface material and is under dense vegetation cover and low relief. In contrast, high D values may be due to the presence of impermeable surface material, sparse vegetation and high relief (Reddy et al., 2004). Low drainage density is associated with run-off processes dominated by infiltration and subsurface flow (Christopher et al, 2010). It has been observed from drainage density measurements made over a wide range of rock types that the drainage densities of whole Dewana basin, Chamy Gora and Chamy Wara Qarawagh sub basins are 2.378, 2.425 and 2.455 1/km, respectively (Table 3.3).
Table 3.3: Areal morphomertic parameter of Dewana basin and sub-basins based on maps of scale 1:50,000.
Whole Chamy Chamy Dewana wara Gora basin qarawa
Daringe Name of area (A) basin in km2
Total stream length in km
Drainge Basin Stream Density length Frequency (D) (Lb) in (Fs) km/km2 Km
Drainage texture (T)
Circularity Elongation Form factor ratio ratio (Re) (RF) (Rc)
99
240.115
2.425
1.828
17
4.022
0.614
0.373
0.343
132
324.087
2.455
2.000
18
5.500
0.720
0.405
0.407
606
1440.806
2.378
1.842
50
8.455
0.437
0.314
0.242
Stream Frequency (Fs)
The stream frequency has been defined as the number of streams per unit area (Horton, 1945) (Table 3.1). Stream frequency also is an indication of dissection that depends on climate and rock type. The values of stream frequencies are 1.842/km2, 1.828/km2 and 2 /km2 for the whole Dewana basin, Chamy Gora and Chamy Wara Qarawagh sub basins, respectively (Table3.3).
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Drainage texture (T) Drainage texture is the total number of stream segments of all orders per perimeter of
that area (Horton, 1945) (Table 3.1). It is one of the important concepts of geomorphology, which indicate the relative spacing between drainage lines. According to Horton, (1945), infiltration capacity is a single important factor, which influences drainage texture and is considered drainage texture, which includes drainage density and stream frequency. According Horton’s scale for texture: Texture ratio
Scale
4 and below
Coarse
4 to 10
Intermediate
10 to 49
Fine
50 and above
Ultra fine.
The drainage textures of stream network are evaluated in the study area, and was found that all basins have the intermediate texture ratio, which are 4.022 and 5.5 /km for Chamy Gora and Chamy Wara Qarawagh sub basins respectively, and 8.455 /km for whole Dewana basin. This reflects the lithology and infiltration capacity of the area (Table 3.3). Because of the stable condition of climate and geology in the area, this medium texture indicates of that runoff rate is low in general due to low precipitation rate over most of the variable lithologic units.
Circularity Ratio (Rc) The circularity ratio is the ratio of the area of a drainage basin to the area of a circle
having the same perimeter as a drainage basin (Miller, 1953 in Bhawan, 1998), and it is a dimensionless index to indicate the form of outline of drainage basins (Strahler, 1964). Miller (1953) in Bhawan, (1998) described the basin’s circularity ratios range between (0.4 and 0.5), which indicate strongly elongated and highly permeable homogenous geologic materials. The circulatory ratio (Rc) is influenced by the length and frequency of streams, geological structures, land use/land cover, climate, relief and slope of the basin (Vijith and Satheesh, 2006). Elongated basin has smoother curve of hydrograph because greater time lag for the water from the upper catchment to reach the outlet. In circular basin water in upper and middle of
52
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catchment reach water the outlet in less time and causes higher discharge during short period (Verstappen, 1983). In this study Dewana basin has value of (Rc=0.437) indicating that it is more elongated in shape, whereas Chamy Gora and Chamy wara Qarawagh sub basin are 0.614 and 0.720 have greater than 0.5 values suggesting that they are sub circular in shape (Table3.3). Circularity bears an inverse relation to basin area (Yusuf et al., 2011), but the correlations is not followed in the present study and hence indicates drainage system of Dewana basin generally structurally controlled by elongated parallel ridge surrounding the basin and forced flow to go in elongated pattern.
Elongation Ratio (Re)
Schuum, (1956) used an elongation ratio and defined it as the ratio of diameter of a circle of the same area as the basin to the maximum basin length (Table 3.1). It is a very significant index in the analysis of basin shape, which helps to give an idea about the hydrological character of a drainage basin. Values near to 1.0 are the characteristics of the region of very low relief, while values in the range of 0.6 - 0.8 usually occur in the areas of high relief and steep ground slope (Chow, 1964) (Nageswara et al., 2010). The elongation ratio values generally ranges between 0.6 and 1.0 over a wide variety of climatic and geologic types. Values are further categorized as circular (>0.9), oval (0.9-0.8) and less elongated (<0.7) (Yusuf et al., 2011). The Re value for Dewana basin is 0.314 but for Chamy Gora and Chamy Wara Qarawagh sub basins are 0.373 and 0.405, which indicates high relief and steep ground slope, so the basin has elongate shape (Table 3.3).
Form Factor (RF) The form factor is defined as the” ratio of the area of the basin and square of basin
length” (Horton, 1932 in Rudraiah et al., 2008) (Table 3.1). It expresses an idea of the width and shape of the basin. It means comparison of basin shape to the triangle shape, the amount of form factor decreases if the shape of basin is wide in upstream of the basin and narrow in the outlet. This shape factor may be interpreted in reference to basin flooding potential in a comparative analysis as low values of form factors are associated with fern shaped basin with large time of concentration and long lag time. If the basins have low Rf
53
CHAPTER THREE
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have less side flow for shorter duration and high main flow for longer duration and vice versa (Reddy et al., 2004). In the study area, the form factor of Dewana basin is equal 0.242 but for Chamy Gora, Chamy Wara Qarawagh sub basin are 0.343 and 0.407, respectively (Table 3.3).This is confirms the triangle shape of Dewana basin. Such shapes depict delayed hydrograph peaks; however elongated basins are unlikely to realize uniform rainfall over the entire basin at same time. Flood flows of such elongated basins are easier to manage than of the circular basin (Christopher et al., 2010). 3.3.3 Relief Morphometric Relationship A third group of parameters shown in Table (3.4) indicates the vertical dimension of drainage basin, these are:
Basin Relief (H) Basin relief is the elevation difference between reference points defined in any one of
the several ways. Total relief within a region of given boundary is simply the elevation difference between the highest and lowest points (Bhawan, 1998) (Table 3.1). The high H value indicates the gravity of water flow, low infiltration and high runoff conditions (Reddy et al., 2004). From table (3.4) we can see that Dewana basin has 1506 m, which is high relief than Chamy Gora and Chamy Wara Qarawagh sub basins, have 685 and 1280 m, respectivly. Steep slopes surface generally have high surface run-off values and low infiltaration rates, and high peak discharge, which lead to sheet, rill and gully erosion(Verstappen,1983).
Relief Ratio (Rh) The relief ratio is defined as the “ratio between the total relief of a basin (elevation
difference of lowest and highest points of a basin) and the maximum measured length of the drainage basin” (Schumm, 1956) (Table 3.1). Relief ratio has direct relationship between the relief and channel gradient. The relief ratio normally increases with decreasing drainage area and size of watersheds of a given drainage basin, high relif ratio indicates high slope area and vice versa , it strongly depends on rock type and rock system (Rudraiah et al., 2008).
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Relief ratio is an indicator of rates of erosion operating along the slope of a basin (Schumm, 1956). From Table (3.4) it can be noticed that Dewana basin has (Rh=0.030), while Chamy Gora and Chamy Wara Qarawagh sub basins are 0.04 and 0.071 respectively.
Ruggedness Number (Rn)
It is the product of maximum basin relief (H) and drainage density (D) (Verstappen, 1983), where both parameters are in the same unit. An extreme high value of ruggedness number occurs when both variables are large and slope is not only steep but long as well (Yusuf et al., 2011). Ruggedness number indicates the structural complexity of the terrain and high values are highly susceptible to erosion (Reddy et al., 2004). In the present study, the ruggedness number are computed as shown in (Table 3.3) , which are 1.661 and 3.143 for Chamy Gora and Chamy Wara Qarawagh sub basins respectively and whole Dewana basin has a value of 3.581. Table 3.4: Relif Morphometric Parameter of Dewana basin and sub-basins based on maps of scale 1:50,000.
Whole Chamy Chamy Dewana wara Gora basin qarawa
Name of Maximum Minimum Basin relif(H) Relief ratio basin Elevation Elevation in m (Rh) in m
Ruggedness number (Rn)
1370
685
685
0.040
1.661
1790
510
1280
0.071
3.143
1871
365
1506
0.030
3.581
3.4 Longitudinal Profiles of Dewana Stream Long profile is the reflections of the major geomorphic factors within a watershed, which includes: climate, rock type, structure, time, and process. All streams that show the same concave-up profile result from balance of erosion and deposition, and base level controls the elevation of the longitudinal profile. Whithin alluvial channels it is generally accepted that a concave –up longitudinal profile is associated with rivers in equilibrium (Ritter et al.,2002)(Rantitsch et al., 2009)
55
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and abrupt discontinuities in the gradients indicate the presence of knick points, which may be interpreted as profile disequilibria. Longitudinal profile of major streams takes several tens or several hundreds of years to respond fully to a climatic change, to variation of drainage basin base level, or to other disturbance to stream regimen (Howard, 1965). Thus evidence about the stage of stream must be informative about the regime changes extending over such interval of time, may be completely in equilibrium with geologic controls and long term climatic average, the some parts like stream cross section will vary in short term climatic fluctuations. Longitudinal stream profiles were constructed for major Dewana stream by plotting the horizontal distance of the stream channels from the source to the mouth, against the drops in elevation (elevation was extracted from DEM in Arc GIS environment by Spatial analyst tools) on arithmetic paper (Fig. 3.10 ). From longitudinal profile of Dewana stream it could be noticed that it has generally smooth linear graph in the upper part but when confluence with Chamy Gora stream and path beside Kalosh mountain it shows little convex-up shape till confluence with Chamy Wara Qara Wagh stream at the plunging of Kalosh anticline, it becomes gradually dropping down till it reaches Diyla river at mouth. From measuring of the slope of the profiles in different location it show that there is change in it in zone of Kalosh anticline (Fig. 3. 12) which shows evidence that stream profile affected by anticline. The shape of profile indicates that the stream doesn’t reach a stage of equilibrium(concave- up curve) and valley development is in young state and erosional processes are still active, similar conclusions have been drived from the result of morphometric analysis of selected sub basins from Dewana valley.
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800 Confluence with Chamy Gora stream
750 700
S=0.5
650 Chamy Waraqarawagh stream Confluence
600
Elevation (m)
S
550
S=0.8
500 Zone of Kalosh anticline
450
S=0.6
400 350 0 Source
10000
20000 30000 Distance (m)
40000
50000 60000 Mouth
Figure 3.10: Longitudinal profile of Dewana stream.
3.5 Interpretation of Results The Dewana stream catchment has a perimeter of 132 km (Table 3.2). The catchment covers an area about 606 km2 and is drained by stream network of the 6th order made up of 1116 streams with 1440.806 km long. The total length of Dewana basin is 50 km. The natural stream has a dendritic, sub trellis, sub parallel and radial patterns which are attributed to the different resistance of rocks and structural control in the basin. Linear morphometric parameter analysis as shown in (Table 3.2) Analysis of bifurcation ratio (Rb) shows local high value (7.1 and 9) in Dewana basin and Chamy Gora sub basin in 3/4 order streams which located in the northern part of the basin indicate that part are structurally controlled, but in Chamy Wara Qarawgh sub basin Rb show low values which range between 3 and 4, attributed to the characteristics of less structural disturbances in this part. Analysis of total length of streams (Lu) shows that Dewana basin has 1440.806 km. The relation between mean stream length and stream order satisfies Horton’s law of stream length except in Chamy Wara Qarawagh sub basin that show decreasing of mean stream length in 4th order stream,possibly due to variation in the slope and topography in this sub basins.
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The length of over land flow (Lo) value of Dewana basin has 0.266 km, if we compare it with 606 km2 basin area it is a short distance so may the surface run off reach the trunk stream channels within a short period and may be responsible in developing storm hydrograph within the basin. Stream length ratio (RL) analysis show that most of the length ratio values are near to eachother,this follos Horton’s law, except in some orders, this is due to lithological and topographic control on the different patrs of the basin.
Areal Morphometric parameter analyzed as shown in (Table 3.3) Area of Dewana basin and its sub basins has been computed and show that Dewana basin is small basin which has an area of 606 km2. The size of basin will controll catchment runoff pattern (discharge) and hydrograph shape (Verstappen, 1983). This is because, the larger the basin, the greater the volume of rainfall it intercepts, and the higher the peak discharge that results. According to this Dewana basin has low Peak discharge and smooth hydrograph will be produced. The analysis of drainage density (D) show that Chamy Gora and Chamy Wara Qarawagh sub basins have 2.425 and 2.455 1/km respectively, and Dewana basin has 2.378 1/km , the high (D) exists in Dewana basin indicates that the region is composed of impermeable surface materials, sparse vegetation and high mountainous relief. The stream frequency of (Fs) for the Dewana basin is 1.842/km2 but 1.828/km2 and 2 /km2 for the Chamy Gora and Chamy Wara Qarawagh sub basins respectively. Analysis of drainage texture (T) show that Dewana basin has medium texture according Horton’s scale for texture which is 8.455 /km. Because of the stable condition of climate and geology in the area, this medium texture indicates of that runoff rate is low in general due to low precipitation rate over most of the variable lithologic units. Circularity ratio (Rc) of the area are computed and show that Dewana basin is more or less elongated in shape, whereas Chamy Gora and Chamy wara Qarawagh sub basins are more or less sub circular in shape. The elongation shape of Dewana basin is lead smoother curve of hydrograph because water needs more time from the upper catchment to reach the outlet, which further depend on the existing geology, which elongated parallel ridge surrounding the basin and forced flow to go in elongated pattern. From this we can conclude that Dewana basin still in young stage of erosional process because it doesn’t have circular shape.
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Elongation ratio (Re) has computed and shows that Dewana basin is elongated in shape while Chamy Gora and Chamy Wara Qarawagh sub basins are sub circular in shape. The form factor (Rf )analysis of the Dewana basin show that it has low value which is 0.242 it show its shape are somewhat fern like or triangle, wider in upstream and narrow in outlet, need more time to reach the outlet so it is less danger for flooding. Relief Morphometric parameter analyzed as shown in (Table 3.4) Basin relief (H) difference of Dewana basin is 1506 m which is high value of basin gradient which indicates high gravity of water flow, low infiltration and high runoff conditions of the study area which lead to sheet, rill and gully erosion. Relief ratio (Rh) determined for the Dewana basin are consederably medium which is 0.030 m, this is the interference that the erosional development of drainage basin is still in young stage. Ruggedness number (Rn) also computed, Dewana basin has value 3.581 indicative structural complexity of the terrain in association with relief and drainage density. It also implies that the area is susceptible to soil erosion. Longitudinal profile of Dewana stream was computed it shows that the stream doesn’t reached a stage of equilibrium(concave- up curve) and valley development is in young state and erosional process are still active.The profile show some evidence of structural control of Kalosh anticline on stream profile.
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CHAPTER FOUR GEOMORPHIC ANALYSIS
4.1 Introduction The geomorphological analysis emphasizes the morphogenetic aspects which is based essentially on assumption that each part of the land surface is the end product of an evolution governed by parent geological material, geomorphological processes, past and present climate, and time (Pavlopoulos et al., 2009). The distinction between cause and effect in the development of landforms is a function of time and space, because the factors that determine the character of landforms can be either dependent or independent variables as the limits of time and space change (Schumm and Lichty, 1965). Geomorphology and particularly geomorphological mapping, provides the ability to identify, impress, and analyze landforms and to associate them with the evolution processes of both superficial and underground relief .The separation of the distinct associations of landforms into the constituent parts is essential for the study of morphology of the Earth. It opens the way to investigate the nature, origin and development of the individual landforms in relationship with the underlying rocks and the geological changes as recorded by them (Oosterom, 1988). Geomorphology, through mapping techniques and as well as understanding of geomorphic processes, contributes to the issues of water resources management, and to issues related both to the hydrological and hydrogeological cycle. Geomorphological mapping is necessary in order to understand climatic changes, and is also the basis for the development of protection and preservation program for these environments (Pavlopoulos et al., 2009).
4.2 Geomorphic Classification and Mapping The Dewana basin has been influenced by various processes which prevail in the shaping of a landform like material removal, fluvial action (erosion and accumulation), structures (endogenetic processes), these processes have in the past and are still acting on soft, competent sedimentary rocks to develop the present landscapes.
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The geomorphological setting of the Dewana basin area was resulted from a close interaction between tectonic activities and lithologic variations, which led to the landform evolution. The most prominent topographic features are often related to the nature of the outcropping resistant rocks. It means that beside the prevailing processes in the area and also rock formations have a great role in shaping of landforms. New research methods for mapping is introduced by using satellite images, aerial photographs, digital photography, 3D anaglyph and digital mapping methodologies will provide high accuracy and spatial resolution which enable modern geomorphologists to produce geomorphological maps, both in print and digital format. Even with all technological advances at our disposal, geomorphological mapping still begins with the identification of the fundamental units that compose the landscape. However, there is no single agreed-upon unit that meets research mapping needs of all types and scales, so it have great complexity. Basic geomorphic units in this study contain two fundamental features of classification which are homogeneity(genetic or structural pattern) and indivisibility at the chosen scale, which is the approach followed by the IGU (International Geographical Union) and most European geomorphologists (Pavlopoulos et al., 2009). The map fall under basic geomorphological map types, which is produced by simple graphic transfer of data directly collected from field survey or image interpretation (Smith et al., 2011). The map was drawn digitally instead of traditional map construction (Condorachi, 2011). The most recent refinement of geomorphological mapping is by using GIS platform which allow correlations with other spatial data (Griffiths and Abarahm, 2008; Hartvich and Vilímek, 2008; Paron and Vargas, 2007; Galve et al., 2009; Gustavsson et al., 2008; Vozenílek, 2003 and Vicente et al., 2009). Digital gemorphological mapping has direct benefits which are: accuracy of position of mapped objects, speediness of data captures and directs using in map creation. There is also indirect benefit which is easily access to that area which is steeps and easily updated data (Longley et al., 2005). In this study the geomorphological mapping is done by following ITC (International Institute for Geo-information Science and Earth Observation) scheme (Zuidam and Zuidam, 1979), and IGU (International Geographical Union) guide, to medium-scale geomorphological mapping (Pavlopoulos et al., 2009).
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The geomorphological map was drawn digitally by using Arc GIS 9.3 software which is verified in the field using mapping scale of (1:150,000); which represents a medium scale according to (Demek and Embleton 1978 in Verstappen, 1983), at which considerable generalisation is required, using both color and symbols to convey information. Major morphogenetic units are colored according to (Verstappen, 1983). Colored area which is purple for units of structural origin, brown is for unit of denudational origin and dark blue for unit of fluvial origin. Minor forms are colored according to major units color but using different hues. Because GIS software lacks suitable symbols for geomorphologic landforms and processes, it is difficult to adopt standard geomorphological symbols. As we know full standardization is only required in the case of the production of a map series at a national or international level (Smith et al., 2011), many new symbol set has been created in GIS environment (Gustavsson et al., 2006) (Mihai et al., 2008). In order to carry out the geomorphological mapping in the Dewana basin in GIS environment, it was necessary to interpret the available data, by locating geomorphic unit and subunit and distinguished each by tracing it as a polygon and line. Each feature was assigned to a unique code and attribute, and was classified according to their origin (Fig. 4.1). Based on the origin and the genetic relations the study area is characterized by five basic geomorphic units which combined exogenetic with endogenetic process and these units are: unit of structural origin, unit of denudational origin, unit of structural and denudational, unit of fluvial origin, origin and unit of anthropogenic origin. Below is general review of the basic characters, association and distribution of each unit and their subunit and landforms.
4.2.1 Units of Structural Origin These are structural landforms of regional extent. The origin and evolution of these landforms are related to the tectonic movements, in addition to the role of structural evolution, structural system of strata and external factors. These are formed as results of folding, faulting, inter bedding of sedimentary rock of different resistance to erosion and its situation (tilted or horizontal strata) in the study area.
62
Figure 4.1: Geomorphological map of Dewana basin.
CHAPTER FOUR GEOMORPHIC ANALYSIS
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4.2.1.1 Central structural ridge This unit represented by most of the Kalosh mountain carapace, which is located in central part of the study area. It is characterized by a high altitude (1400 m.a.s.l) relative to the surroundings. The Pila Spi rocks of this ridge are more resistant to erosion than the easily eroded surrounding rocks, such as Fatha and Injana formations. It is basically formed on limestone and dolomitic limestone of Pila Spi Formation (Fig. 4.1). It represents a asymmetrical anticline, with northestern limb is the steeper side (Fig. 4.2). Both limbs are dissected by parallel valleys. Cutting deep into the hard Pila Spi limestone and the flanking softer rocks of the Fatha and Injana formations.
1
2
3
Figure 4.2: Show satellite image and topographic profiles of Kalosh anticline.
4.2.1.2 Outer homoclinal structures ridges These are major structural ridges surrounding the study area from both side of the basin. They are composed of resistant limestone of the Pila Spi Formation, the dip angle of these ridges are relatively high and critical to the angle of repose of the rock slide of its slopes (Bloom, 1998). They form hogback in the southwestern site of the study area, the interfluves remnant of dissected hogback is called Flatiron topography (Fig. 4.3). The dissection will be along fault lines, stream cutting steep gorges that erode headward; progressively, or wind gap were stream piracies have produced wind gaps in the ridges 64
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through which transverse streams formerly flowed (Thornbury, 1969) (Fig. 4.4). There is a rapid change in the dip amount because of weathering of incompetent rock of Fatha Formation along the lower parts of the slopes (Fig. 4.1).
Flatiron
Figure 4.3: Flatiron on northeastern limp of Sagerma anticline
Figure 4.4: Wind gap across Qara Dagh mountain.
4.2.2 Units of Dunudational Origins This group of landform is formed by the active and continuous process of erosion on the original landscapes by repeating action of denudation with the operating geomorphic agents like water, wind, and climatic components; like rainfall, temperature change. Etc. (Roy et al., 2010). Denudation which is the meaning of joint action of weathering and erosion, that processes simultaneously wear away the land surface (Huggett, 2007). This group includes the following landforms; Foot slopes, badlands. 65
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4.2.2.1 Foot slopes Foot slopes are usually erosional, but may also be depositional, foot slopes are between mountain fronts and valley or basin’s bottoms. They commonly form extensive bedrock surface over which the weathering products from the retreating maountain fronts are transported to the basin (Zuidam and Zuidamm, 1979). Erosional foot slopes have gently inclined erosion surface, they are carved in bedrock by weathering and erosional processes, they can be recognized from rapid slope change of structural ridges of anticlines, they represent transitional stage between erosion and deposition and regression of the structural ridges. Foot slope in the study area are divided in two sub units (Fig. 4.1): A. Foot slope with residual ridges: This sub-unit is developed on foot slopes of Qaradagh mountain and Baranan ridge in the northwest and northeast of Dewana basin respectively, over Fatha and Injana formations. This form represents residual strike ridges left on foot slopes as a remanents of dissection and erosion. B. Foot slope with ridges and furrows: This sub unit is developed in the foot slope of Gwllana’s mountain in southwestern of Dewana basin, over Fatha Formation. They form a shape of successive ridge and furrows which are developed by different erosional process (Fig.4.5).
Figure 4.5: Satellite image shows ridges and furrows in Gullan mountain foot slope. 66
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4.2.2.2 Badlands Badlands are deeply dissected erosional landscapes formed in soft rock terrain commonly, but not exclusively in semi-arid regions. Badlands usually have a high drainage density of rill and gully system, which are characterized by rugged topography so do not have significant land use or vegetation cover (Fig. 4.6). Two prerequisites for badland development are important: erodible rock and high relief (Goudie, 2004). Badland topography is well developed in the study area in most of the synclinal area; consists of hard sandstones alternated with soft claystones and siltstones. Beside, the presence of strike ridges (Fig. 4.1), few area of study area are charecterized by presence of cuesta; which are composed of resistant sandstone that capped soft siltstone and claystone of Injana Formation, they are asymmetrical ridges with gentle dip slope (5°to 15°) and steep escarpment. These landforms are formed from differential erosion of the exposed rocks and the structural attitude of the strata (Aqrawi, 1990).
Figure 4.6: Badland landscape in the study area
4.2.3 Units of Structural-Dunudational Origin This group of landform is formed by tectonic movements in addition to the active and continuous process of erosion on it by repeating action of denudational processes. This unit can classified into erosional core of Sagerma anticline and structurally controlled denudational hill influenced by fluvial erosion sub units.
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4.2.3.1 Erosional core of Sagerma anticline This unit is structurally controlled and represents an eroded landscape. It represents an early observation of topographic inversion where anticlinal axes become valley, where anticlinal axes have been breached by erosional processes in the zone of weakness and fractures. This unit occupies the core of Sagerma anticline in the northwestern part of the study area and is surrounded by escarpments of the Pila Spi and Sinjar formations (Figs. 4.1, 4.7 and 4.8), with core soft sediments of the Kolosh and Gercus Formation were easily eroded forming anticlines’ valley. It is also developed with step-escarpment due to Sagerma Fault along fold axis (Stevanovic and Markovic, 2003) which facilitates erosional process. Anticline core
Erosional surface
Figure 4.7: Erosional core of Sagerma anticline.
Figure 4.8: Erosional escarpment flanked the Sagerma anticlinal core.
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4.2.3.2 Structurally controlled denudational hill influenced by fluvial erosion It is a structurally controlled remnant hill located in the northestern of synclinal trough of Dewana basin, formed on Bi Hassan and Muqdadya Formations, it’s dimension around 82.2 Square Kilometers, and reach 1196 meter in elevation, It is called Barzy Dollan mountain. The attitude of beds is near horizontal with small degree of dip angle. An active gully erosion is prevailing in the area due to active fluvial erosion (Fig. 4.9), also high permeability of Bai Hassan Formation, and its weakly resistant rocks to erosion have led to form rounded crest line over it. The structural terraces are formed on Mukdadiya Formation because of differential erosion due to alternating soft and hard rock’s leading to overhanging protrusion of hard rock (Fig. 4.10) (Fig. 4.1).
Figure 4.9: Gully erosion on Barzy Dolan mountain, northern of Dewana basin
Figure 4.10: Structural benches in denudation hill area, Dewana basin. 69
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4.2.4 Units of Fluvial Origin Fluvial landforms are generated by the action of rivers or streams and the processes associated with them (Roy et al., 2010). The fluvial units in the study area include: Seasonal dry valley deposits and old alluvial fans. 4.2.4.1 Seasonal dry valleys deposits This unit forms Dewana stream bed and its major tributaries, in addition to its surrounding flood plain. They are the most easily detectable landforms on satellite images, however other associated small scale landforms and subunits are hard to be recognized from these image and often were identified from topographic maps and land survey. The stream network is well described in chapter three. The other fluvial subunits and landforms include:
Flood plain sediments: These are very locally developed along meanders or wide
channel of the Dewana perennial stream. They are irregular small plains which are covered by water during flooding seasons. These plains are composed of poorly cemented sand, silt and rarely gravels. The thickness is less than one meter. Two stages are recognized in the study area (Fig. 4.11), these areas represent a fertile land for agricultural activities.
Baranan Homocline Flood plain 2 1
Figure 4.11: Flood plain near Tazade village between Baranan and Kalosh mountain.
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Channel deposits: These are river sediments spread in the study area within
channel, characterized by filling with mixed gravel, sand and rock fragment of high mountains7 The thickness of these sediments will increase as distance increase from mountaneous area (Fathi, 2001). The size of these sediments grains on the other hand decrease in that direction they are composed of cobbles and pebbles, mainly of limestone, rounded to well rounded, rarely sub rounded, range in size from few millimeters up to (15 – 35) cm, the thickness ranges from (0.5 - 4.0) m. Morphologically, they form a string or a trial of elongated body ,sometimes shows meanders or sinuous following valley shape7 It often fill the river channel completely especially when grain size is coarse. When channel is wide, mixed sediments are recognized and partly filly river channel (Fig. 4.12).
River terraces: Are topographic surface which mark former valley floor levels or
former flood plains (Thornbury, 1969). These terraces like surfaces are formed because of responsese to fluctuations of geomorphic processes which is reflected on the fluvial system (Bull, 2007). Among these processes climatic changes and tectonic activity. They are oftenly developed in pairs and located whithin the river valley at relatively higher levels forming a terrace or a bench looking down the river channel. In the study area two certain levels of river terraces are recognized near Dewana village along the main channel. These terraces are discussed as belonging to Diyala river and belived to represent 2-3 flooding stages (Armaghani, 1992). The lower one about 2m in thickness and it is about 4 m above stream bed (Fig. 4.13), while the upper one reaches 2-3 m and is about 10m above stream bed (Fig. 4.14). The pebbles are mainly of limestone and some chert and sandstones, with subordinate amount of igneous and metamorphic rocks. Pebbles rounded to well rounded, range in size from few millimeters up to 20 cm, well cemented with sandy and calcareous materials, to the south of the right abutment of the proposed dam for Dewana river terraces also detected and described by (Working Group, 2009 a).
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Figure 4.12: Channel deposits, Dam site location southern of study area.
River terraces
Figure 4.13: Lower river terrace of Dewana stream, near Dewana village. River terraces
Figure 4.14: High level of river terraces with rock fans in the lower most part of the scarp, near Dewana village. 72
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4.2.4.2 Old alluvial fans Alluvial fans are cone-shaped bodies that form where a stream flowing out from mountains debouches onto a plain (Huggett, 2003). In the study area several locations with sediment accumulation were recognized at the foot of Qaradagh mountain, they are relatively small steep apex area with gentler and wider distal area. Generally the fans vary considerably in morphology and extent because of varying characteristics of catchment areas and different local base levels, that composed of thick deposits and some parts of the fan lost due to younger erosion processes (Figs. 4.15 and 4.1).
Figure 4.15: Satellite image of old alluvial fan near Balkha village southeast of Qara Dagh mountain.
4.2.5 Units of Anthropogenic origin The land forms of this unit are formed because of different human activities, so their origins are artificial (Al-Daghastani, 2004). Some landforms are produced by direct anthropogenic processes. In the study area and despite its semiarid climate human activities were spread over most of the Dewana basin, especially in the central depression area. Tens of villages were established along main stream and major tributaries which are connected by paved and peneplained road network. All causes, a variation in the general surface morphology of the area. Major dam project to be constructed downstream of the river near Darbandikhan has and will modify the landscape of the area (Fig. 4.16). Agricultural activities such as, Terrace farming (Fig. 4.17), channelization, irrigation 73
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channel construction, and farming ditches are considered to be important anthropogenic agents. An indication of ancient human activity in the area is displayed by sculpting of an archeological form as in Derbendi Gawr at Qara Dagh mountain. It is one of the famous archaeological rock reliefs on the Pila Spi Formation (Fig. 4.18). Other landform is affected by indirect anthropogenic work like; acidic rain, global warming which affect weathering rate.
Figure 4.16: Constructing a dam project along Dewana downstream
Figure 4.17: Terraces farming, Dukan village,Dewana basin. 74
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Figure 4.18: Naramsyn sculpture on Pila Spi limestone Formation, Darbandi Gawr.
4.3 Geomorphic Processes Geomorphic processes are consequence of a combination of natural processes acting upon earth-surface materials (Goudie, 2004) which leads to its modification. Geomorphologic processes are varying in intensity from one region to another, depending on climate ,vegetation, time, and altitude (Bloom, 1998).The influence of a past process having acted upon a geomoephic system is proportional to the intensity and duration of its action, but inversely proportional to the elapsed time since its action(Howard,1965). Several processes are responsible for the geomorphic evolution of Dewana basin that can broadly classified into two types following (Holmes,1965) classification; these are: Endogenetic / processes of internal origin which act within or through the earth’s crust such as earth movement(mountain building by folding and over thrusting of rocks and uplift of land area), and exogenetic / processes of external origin which act on the 75
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earth surface, as a result of mechanical and chemical activity of air, water and living organism. The later processes operate under the control of gravitations. 4.3.1 Endogenetic processes: The processes, which are responsible for mountain building in the study area such as orogenic movement, which include most tectonic deformation and structural development of landforms. It is usually the result of late Cenozoic land movement (Bloom, 1998). The study area of Dewana basin represents part of the Zagros mountain of northeast Iraq. It is developed during the evolution of the Zagros Orogeny and represent part of the folded belt of that orogeny (Jassim and Goff, 2006). It is resulted from the collision of Sanandaj-Sirjan block and Arabian plate during Late Eocene or beginning of the Oligocene which is represented on the surface by formation of the NW-SE trending folds and faults in the Zagros Foreland High Folds Zone. They are represented by Baranan-Darbandikhan anticline which is assumed to be Middle to Upper Oligocene 28.4 Ma. Baranan Homocline was formed by backthrust fault ranges between ~ 23 Ma and 20 Ma, Sagrma anticline Lower Miocene younger than 23 Ma, and Kalosh anticline which is younger than Sagrma anticline (Ibrahim, 2009). These deformational processes were responsible for the regional geomorphic buildup of the area and its major structural units such as ridges, homoclines .etc. 4.3.2 Exogenetic processes: The processes are responsible in forming those landforms that had developed by agents active on the earth surface such as: denudational and depositional processes by river, wind, glaciers, wave.etc. However most landforms are affected by both processes simultaneously. 4.3.2.1 Denudational processe: Is an umbrella word covering three main types of rock change and removal processes; these are weathering, mass wasting, and erosion. 4.3.2.1.1 Weathering Is the decomposition and disintegration of rocks and minerals at the Earth’s surface that involves little or no movement. All types of weathering are active in the study area, but according to Peilter (1950) diagram and climatologically data (Fig. 4.19), it show that very slight weathering ; weak chemical weathering and moderate mechanical weathering but because chemical weathering is much more subtle than mechanical weathering it could be seen in the field rather than second one. The study area characterized by minimum mass 76
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movement, maximum wind action and moderate fluvial erosion. The influence of the climate on the intensity of chemical weathering depends on the availability of moisture and high air temperatures but mechanical weathering depends upon the presence of water but is very effective where repeated freezing and thawing occurs (Huggett, 2007). Weak chemical weathering in the study area are referenced to the semi-arid condition and limited rain fall (moisture) and temperature in the area, while moderate mechanical weathering in the study area are due to medium range of temperature (Tables 2.1 and 2.2).
Some features had been seen during the field work and were photographed they illustrate weathering processes actions in the area among these processes are:
Abrasion: is mechanical weathering where many rock fragments along a stream
are rounded and smooth edges particles collide, their sharp edges and corners wear them away and grinding them by friction impacts (Thompson and Turk, 1997). Roundness of these rocks will increases with increasing of transportation distance and particle size will decrease with decrease in hardness (Bourke and Viles, 2007). Along Dewana stream (especially in downstream) this process can be seen, were edges rounded and sub-rounded gravel are common as a result of abrasion (Fig. 4.20)
Figure 4.19: Peilter’s diagrams show weathering regions, red point is study area (Peilter, 1950)
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Figure 4.20: Rounded and sub-rounded gravels in a stream bed in lower reach of Dewana stream.
Slaking: It occurs when minerals absorb water molecules on their edges and
surfaces, hydration is transitional between chemical and mechanical weathering and some time say Wet–dry weathering causes disintegration of rocks. Studies have demonstrated the importance of surface swelling developed in mudstone; nonetheless, clay-rich rocks are susceptible to slaking with or without the presence of salts (Goudie, 2004). The effect of this process can be seen in claystone in Fatha Formation which during increasing moisture in wet season, start to swell and shrink; when they are dry out then act as lubricant surface for sliding (Fig. 4.21).
Figure 4.21: Claystone between limestone beds in Fatha Formation promotes sliding when it becomes wet, road to Qopy Qara Dagh northwestern part of the studied area.
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Shattering and rock splitting: It is rock disintegration by thermal expansion and
contraction during daily and seasonal changing in temperature or by growth of tree roots down into the cracks and facilitates the rock fragmentation or disintegration (Fig. 4.22).
A
B
Figure 4.22: Rock shattering and disintegration by thermal expansion (A) and growth of tree roots (B).
Spheroidal weathering: In the weathering process, there is a universal tendency
for rounded (or spherical) surfaces to form on a decaying rock body regardless of the original shapes of the rock fragments. A rounded shape is produced because weathering attacks an exposed rock along joint planes, and rapid decomposition along the joint planes. Examples of spheroidal weathering can be seen in Injana Formation sandstone bed and edges (Fig. 4.23). On each block weathering proceeds inward from the joint face
A
The corners of the block are soon completely decomposed so the rock assumes a spherical or ellipsoidal shape.
B
Figure 4.23: Development of spheroidal weathering of sandstone of Injana Formation. 79
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Karren or lapies: Are grooves or rills produced by chemical weathering through
carbonation or simple solution by acidic water, most carbonate rocks are sensitive to this type of weathering,when carbon dioxide dissolves in rainwater it form carbonic acid (CO2 + H2O →H2CO3) which dissolves carbonate sedimentary rocks like limestone or other carbonate-rich rocks (Williams, 2005). Any increases in acidity increase the rate of weathering reactions (Holmes, 1965), while calcite has modest solubility in pure water if saturation concentration about 13 mg/l at 16◦C and about 15 mg/l at 25◦C (Huggett, 2007). These forms can be seen in Sagerma mountain on the limestone of Pila Spi Formation (Fig. 4.24).
Alveoli: Alveoli are small cavernous weathering features which usually occur in
groups. Individual alveoli are separated from their neighbors by narrow, intricate walls, creating an overall honeycombed surface (Bourke and Viles, 2007). This feature can be seen in the study area in Darband Gawr gorge (Fig. 4.25).
Tafoni: Are large (usually over 1m in diameter) cavernous weathering features,
often developed towards the base of large boulders, they are characterized by having a flaking back wall and an overhanging lip in front. The opening of the tafoni is often nearcircular, and the occurrence of tafoni on sandstone surfaces has frequently been documented (Goudie, 2004). In the study area these feature can be seen on sandstone of Injana Formation (Fig. 4.26).
Figure 4.24: Karren, formed due to water solution by rain water
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Figure 4.25: Alveoli developed in limestone of Pila Spi Formation.
Figure 4.26: Well-developed eroding tafoni in Injana sandstone. 4.3.2.1.2 Mass wasting Is the collective term for all gravitational or down slope movements of weathered rock debris in which water may play a role as a lubrication (Bloom, 1998). These processes are noticed in the studied area in different form and type as follow:
Slide: Where mass of rock or weathered debris moved down hill along discrete
shear surface which are usually bedding joint or fault surface (Thornbury, 1969)(Bloom, 1998). The material always rock bodies, and the reason of sliding is related to the special geological setting (Ghareeb,1983) and friction angle. Transitional rock slide detected in the study area which happened where steeply dipping strata slided parallel to the bedding planes down slope, it is noticed along road cut rock sliding had occurred on bedding plane
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of claystone bed in Fatha Formation in the flanks of both ridges of Dewana basin due to removing supporting rocks (Fig. 4.27).
Figure 4.27: Rock slide on detritus Limestone of Fatha Formation, along the road to Qopy Qara Dagh, NW of study area
Rock Fall: Is the downward movement of rock bodies through the air (Huggett,
2007) takes place when recently detached rock blocks, usually small, move precipitously down a steep cliff or rock face (Thornbury, 1969). It is common along slopes from accumulation of rock fragments at the toe of the slopes in the study area (Fig. 4.28).
Soil Creeping: Is barely perceptible and non accelerating down slope movement
soil creep or rock creep (Huggett, 2007). The source of rock boulders is rock fractures by the mechanical process beside secession of hard rock over soft rocks (Ghareeb, 1983). This phenomenon is noticed at slope foot of gentle degree. Evidence of this process is often bending trees and fences (Fig. 4.29).
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Figure 4.28: Rock fall along Pila Spi cliff, Sagerma mountain.
Figure 4.29: Down slope creep as evidenced by bend of tree, near Qaraman village.
4.3.2.1.3
Erosion
Is transporting and removal of weathering product over much greater distances by erosional agents such as wind and/or water. Erosion causes fine grains to travel great distances (Williams, 2005). It is often used to indicate the overall exogenic process or group of processes that are directed at leveling off earth relief in contrast with the endogenic processes that build up landforms. Landforms developed by erosional process 83
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are particularly striking features than depositional landforms (Goudie, 2004). Water is the main source of erosinal process in the study area, different types of erosional features are prevailing in the area which includes:
Rill Erosion: Rill erosion occurs as runoff begins to form small concentrated
channels over steeper slopes in relatively soft rocks or sediments. This phenomenon is frequently noticed at gentle slopes of Injana Formation where claystone is exposed on the surface (Fig. 4.30).
Gully Erosion: Gully erosion results from water moving in rills, which concentrate
to form larger and deeper channels. When rill erosion can no longer be repaired by merely tilting, it is defined as gully erosion, and become a wider in the upper reach and called head ward erosion (Fig. 4.31).
Stream Channel Erosion: Stream channel erosion consists of both stream bed and
stream bank erosion. Stream bed erosion occurs as water flow cut into the bottom of the channel, making it deeper and narrower (Fig. 4.32). In meandering channel stage where stream flow energy slowed channel erosion become lateral and cut into bank sediments forming steep cliffs (Figs. 4.33 and 4.34). 4.3.2.2 Depositional processes: This process creates landforms due to the accumulation of sediment, aggradations occurs in areas in which the supply of sediment is greater than the amount of material that the system is able to transport. The study area is dominated by fluvial deposition process which is noticed active in most parts of the basin. Depositional features associated with this process includes: alluvial fans, slope foot deposits, channel deposits flood plain, valley fill sediment and related features.
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Figure 4.30: Active rill erosion, near Dukan village.
Figure 4.31: Bottle neck showing head ward erosion near Wlyan village.
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Figure 4.32: Panorama view of down cutting by Dewana stream branch.
Figure 4.33: Bank erosion of Dewana stream along its meander way
Figure 4.34: Channel deposits (point bar) at the convex side of Dewana stream, near Kalosh Village.
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CHAPTER FIVE GEOMORPHIC APPLICATION 5.1 Preface The greatest potential for applied geomorphology exists in the investigation and prediction of geomorphic processes and their possible effects. The major problem is that little is yet known about the speed of most geomorphic processes (Beach, 1982). Applied geomorphologists are more likely today than ever before to be establishing contacts with a variety of environmental managers and technicians, engineers, farmers, planners, foresters, and politicians. In addition, his staple reading material is likely to be expanded
to
include
economics,
planning,
engineering,
management,
hazards,
environmental perception, and law. Geomorphology is applied for the solution of miscellaneous problems, especially to the development of resources and the diminution of hazards, for planning, conservation and specific engineering or environmental issues (Goudie, 2004) The applied geomorphology in the last three decades became much more central and accepted part in all disciplines in the nature because of increasing awareness of the complexity of environmental conditions and the significance of geomorphological hazards,demand from engineers for more information on ground conditions for construction purposes, and
development of more precise techniques for mapping,
monitoring and analysis. The Dewana basin involves medium size basin of perennial stream (Fig. 5.1), with limits land use and application of basin terrain as it should involve rough high-relief topographic region in the upper reaches of the basin with mountainous relief in the middle and modest to flat relief at lower part of the basin. The Dewana basin contains 63 villages, major type of activity in the area are agricultural and animal breeding, which 71282 Acre are used for forest and 67683 Acre are used for natural grazing (General directorate of forest/Sulaimani), some projects are sponsored by government such as Astel and Plastic houses (Fig. 5.2).
87
88
forest/Sulaimani).
Figure 5.1: Land use map of Dewana basin (compiled from land use map, scale1:1,000,000, General directorate of
CHAPTER FIVE GEOMORPHIC APPLICATION
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GEOMORPHIC APPLICATION
Figure 5.2: Plastic houses in fertile bed, Daluja village.
5.2 Water Resources Management Water is one of the most important renewable resources which have direct and indirect effects on the life pattern of people. The role is more serious in study area because it is semi-arid climatic condition such as most of Kurdistan region. According to the fact that most of water resources in Dewana catchment area are seasonal-mainly spring floods with very rare exceptions, therefore water uses and beneficiaries are deprived
and non
significant. Thus the needs for water increase daily as the population increases and develops that lead increasing demand for drinking, manufacturing, sanitation and agriculture. In fact, Kurdistan region is rich enough in water resources but very poor in water development projects. Presently, attention had been paid, efforts are spent and some potentials are given by the Ministry of agriculture and Water Resources, Kurdistan region as well for the preparation of an efficient plan for developing water resource and harvesting waters. Among these projects that constructed or will be constructed are:
5.2.1
Dewana dam construction
The dam will be constructed on the Dewana perennial stream, it is located in about 2km southwest of Darbendikhan town (Fig. 5.1). It is important for harvesting huge
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amount of rainy water, regulate and controlling the spring floods of Dewana valley, irrigation water supply and municipal water supply. The dam specifications are: height of 420 m a.s.l, bed level at 380 m a.s.l., dam upper length: 377 m, free board 4.40 m at 415.60 m a.s.l., crest width: 10.30 m at 420 m a.s.l., spillway crest at 415.6 m a.s.l, reservoir upper area is 1 318 000 m2 at 415.6 m a.s.l, reservoir volume 25.75 x 106 m3 at 420 m a.s.l, reservoir max-capacity is 19.2 x 106 m3 at 415.6 a.s.l.. The dam is an earth fill with central clay core and gravel shell, dam site and the reservoir cover about 6 Km2 (Working group, 2009 b). The dam reservoir will not impact on the villages around it because the water level not exceed the elevation of the surrounding villages, but will cover some agricultural land around it. The dam will impact on flow and sediment transport regimes. These processes changes induce adjustments of the size and shape of the river channel, and the form of the floodplain. These changes of the flooding and sedimentation regimes together with the changes to the morphology of the river corridor impact upon plants and wildlife by changing the habitats available for biota (Goudie, 2004).
5.2.2 Karez karezes are subterranean aqueduct are engineered to collect groundwater and direct it through a subsurface tunnel with a gradual slope, to surface canals that provide water to settlements and agricultural fields (Lightfoot, 2009) (Fig. 5.3). These aquifers are usually shallow, a few meters to tens of meters deep and located in areas of permeable rock, thus allowing regular recharge to the aquifer. Within the areas that lack natural surface water supplies and receiving 500-750 mm average annual rainfall makes karez an attractive option for water supply. All of the longer karez in Kurdistan are found in the broad alluvial plains that exceed 4 km in length around Qaradagh region. The shortest karez are 10-20 meters in length, usually found in limestone. A single karez has the potential to provide enough household water for nearly 9,000 individuals and irrigate over 200 hectares of farmland. Qaradagh region is one of the densest concentrations of karez in Iraq. Along the eastern side of the Qara Dagh range there are numerous villages with many karez. As a result developed an agricultural tradition and karez irrigation (Fig. 5.3).
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Sewsenan village contains 35 infiltration karez and 10 of these karez were still being used in 2009. Jafaran village west of Qaradagh, 44 of 52 karez became dry during the years 2008-2009; only eight still flow cause of dry up these Karez is by pumped wells and drought that reduced aquifer recharge. In other villages Faqira, Bakhan, Balkajar, Blaka, Darawyan, Daryzayan, DolanSaru,
Sarko,
Tafan,
Takya,
tilazet,
Timar,
Wlyan,
Gomata,
Qaraman,
Qamisham..etc., 65 karez are found (19 were flowing in 2009) (Lightfoot, 2009).
Figure 5.3: Show cross section of Karez (by Samuel Bailey in www.Wikipedia.org) 5.2.3
Weirs or flumes
Weir are dam like barriers or overflow structure constructed across an open channels in order to measure flow rates(discharge).The shape of the notch when viewed from upstream or downstream may be rectangular, triangular, or some other regular geometric form(Dingman,2009). The structure consists of a ponding basin, a stilling well, a V-notch "weir", a flume, and concrete "wings", which reach slightly outwards uphill to catch and direct the stream and any nearby ground water into the flume and basin. Effective use of water for crop irrigation requires that flow rates and volumes be measured and expressed quantitatively. In the study area weir was constructed which have rectangular notch and 1.65km length, near Astel village (Figs. 5.1 and 5.4).
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Figure 5.4: Weir as irrigation project near Daluja village.
5.3 Slope Stability Evaluation Ground surface slope affect directly the geographical distribution of human. Human reacts with natural environment so the style of habitation, distribution and size will be affected. There is an inverse relationship between slope angle and land use, people always used to settle and grow in those areas that have low slope angle such as plain, flood plain and valley. Peoples in Dewana basin are distributed in those areas that contain source of water, have fertile land for agricultural use and easy way for transportation. There are numerous techniques to measure slope directly by manual methods in field observations and indirect measurements from maps and aerial photographs (Goudie, 2004). Advances in computer technologies especially GIS technologies and the availability of Digital Elevation Model (DEM) have significantly applied in slope analysis in the last decades. For this study we classified slope of Dewana basin following Goudie (2004) and Longley et al., (2005) technique, by using gridded DEMs in Arc GIS 9.3 environment, five classes are distinguished according to Zink (1988-1989) geomorphological classification of slopes, that classes began with (0-1°) and finished by (30° and more) as in (Fig. 5.5). The following steps show preparation of slope map (Price, 2010): 1-Add the grid DEM to the Arc GIS environment. 2- Open 3D Analyst tool. 3- Chose surface analysis and then Slope.
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Figure 5.5 Slope map of Dewana basin.
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4-Classify the slope class according to (Zink 1988-1989) into 5 classes in symbology tab in layer properties. 5-Choosing spatial analyst then reclassify (we classify the slope into 5 class regarding Zink classification). 6-Using majority filter (5-cell-by-5) neighborhood statistics from surface analyst to eliminate small area inside their opposites that simplifies the slope class. 7-Converting raster to feature for creating polygon for slope classes (Table 5.1). Table 5.1: Zink (1988-1989) classification for earth slope with geomorphic sub-units.
Form
Slope in Degree
Classes
Valley and syncline
0-1.9
plaine
Badlands/Footslopes Peniplain, footslope
2-7.9
Simple curvature
8-15.9 16-29.9 > 30
Curvature Isolated Highly dissected
Geomorphic subunits Old alluvial fans/ Terraces
Homoclinal ridges Central ridge
Low hills high hills Mountains
From the slope map it appears that the study area has the following classes of slopes: Class 1: The slope of this area is ranged between (0_1.9°), they represent 1.32 % of study area (Table 5.2), these slopes are stable area and suitable for all human activity like agricultural and the construction of buildings, roads. Distributed in the valley bottom and in some part of the synclinal valley. Two villages are located in this range of slope (Fig. 5.5). In the bad land area influenced by fluvial erosion geomorphological sub unit, surface material of this area mostly composed of Injana Formation and Quaternary deposits. Class 2: The slope angle of this area is ranged between (2°_7.9°). They covered 41.91% of study area (Table 5.2), and it represents the most extensive class that distributed in synclinal depression in the basin, 41 villages are located in this range of slope and two towns (Fig. 5.5). In the badland area influenced by fluvial erosion and some part of foot slopes with residual ridges geomorphological sub unit, surface materials of this area are
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composed of Injana and Fatha Formation. Land use in this area is limited because there are obstacles, it is possible to be used for agriculture activity if it meets natural conditions.
Table 5.2: Showing area covered by each class in the study area 2 Class No. Slope classes in degree Area km percentage 1 (0-1.9) 8 1.32 2 (2-7.9) 254 41.91 3 (8-15.9) 182 30.03 4 (16-29.9) 127 20.96 5 (>30) 35 5.78 total 606 100.00
Class 3: The slope angle of these area is ranged between (8°_15.9°). They represent 30.03 % of study area (Table 5.2), this class is distributed in high elevated areas and some valley sides of the basin as in Barzy Dolan mountain , Kalosh mountain flanks and foot slope of ridges around the basin, 16 villages are located in this class (Fig. 5.5). In some parts of the foot slopes, structural denudational hill and erosional core of Sagerma anticline sub units, the surface materials are composed of Muqdadya, Bi Hassan and Gercus formations. These areas are more active in weathering and erosion processes, so they should not be free of vegetation, because its presence reduces the activity of processes and stabilize the soil in the study area. Class 4: The slope angles range between (16°_29.9°), they represent 20.96 % of the study area(Table 5.2), this class exists in hill side area of the ridges that bound the basin and limbs of Kalosh mountain, there are 4 villages in this class (Fig. 5.5).These slopes are distributed in foot slope with risedual ridges and outer homoclinal ridge sub units, surface materials are composed of Fatha Formation. This area is more volunarable to the denudational process than the surroundings. This area is not suitable for human activity except animal breeding, if they want to use it for agricultural purpose it must be use contour or terraces technique. Class 5: The areas when slope angles exceed (30°).They represent 5.78 % of the study area (Table 5.2), they are distributed in a high mountains such as Sagerma, baranan, Qara Dagh range and Kalosh mountain peak. There is no location of villages in this class (Fig. 5.5). In 95
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the apex of outer homoclinal ridge sub unit, surface materials are composed of Pila Spi Formation. These areas are not suitable for human activities because of high angle slope and rocky terrain.
5.4 Geohazards of Dewana Basin Determination of hazardous area or mapping of hazardous ground is another application of applied geomorphology that facilitate in choosing optimal location of engineering structures and urban planning in the future, also to protect and warn people from any disaster that may happen in the area. The Dewana basin shows some exceptions and some types of geological hazards which may occur in the study area (Sissakin et al., 2008) (Fig. 5.6). From field observations, some hazard phenomena were observed like:
5.4.1 Slope instability and mass wasting It is the down slope movement of earth material primarily under the influence of gravity. Small scale andslide is one of the problems in the study area, particularly in mountain area that they have steep slope. In those areas that are cut by road construction and destroyed the protecting side of these bedding planes. These problems occurred on Fatha Formation in northwestern and northeastern side of Dewana basin along the side roads. Slope angles in this area range between 16° and 29.9°, and therefore lower threshold of precipitation may initiate landslide in north western side (Figs. 5.7 and 5.5), removing the hazard rock part is recommended to prevent any accident along this road. Some rockfall phenomena are observed in study area on slopes of Injana Formation, especially near the proposed dam site (Fig. 5.8). These blocks up to few cubic meters are fallen down. Therefore these blocks may acts as obstacles along channels that reach water to peoples and will accumulate in the reservoir later. Few rocks fall site are observed on Pila Spi Formation in the cliff around the basin and in the core of Sagerma anticline, the slope of this area are more than 30°, because in the western side of Sagerma Anticline constructed road and this area is a place for tourism so people must pay attention on this phenomena.
96
Figure 5.6: Hazard map of Dewana basin (Sissakin et al., 2008).
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Figure 5.7: Possible land slide in Fatha Formation along bedding plane.
Figure 5.8: Rock fall in Injana Formation at river bank.
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5.4.2 Soil erosion Soil erosion is another hazard problems in the study area. The annual total soil loss volume for the whole Dewana watershed is 6.03 x 105 m3 according to (Working group, 2009 b). Knowing that analytical and experimental studies had showed that runoff which is originating from rainfall intensity is the major reason of erosion, because the majority of the slopes are formed by soft materials like claystones and siltstones and all existing slopes drain towards Dewana perennial stream, basin. Therefore the weathered and eroded soft rocks will be laid down in the reservoir, consequently increasing the siltation rate. This case is valid not only in the reservoir area, but also along the whole catchments area of Dewana perennial stream, gulley and rill erosion is another problem in the study area specially in the bad land area so preventing erosion in the area is important by: 1. Stabilizing techniques to prevent sheet erosion such as temporary and permanent vegetation, sodding, mulching, compost blankets, and rolled erosion control products absorb the impact of raindrops and protect the ground surface. By protecting the surface, soil particles are not dislodged and transported by sheet flow. Typically, sheet flow does not have sufficient volume or velocity to dislodge soil particles from a bare surface by itself. It is dependent on raindrop impacts to disturb the surface. Diversion structures may be used to reduce the volume of flow over a bare slope, and surface roughening techniques can be used to reduce the effective slope length of the surface by breaking up sheet flows. 2. Repairing rilling by tiling or discing and should be repaired as soon as possible in order to prevent gullies from forming. 3. Using utilizing earthmoving equipment for repairing gully erosion can be prevented by quickly repairing rill erosion and addressing the cause of the rill erosion. 5.4.3 Flooding Be aware of flood hazards no matter where you live, but especially if you live in a lowlying area, near water or downstream from a dam. Even very small streams, gullies, creeks, culverts, dry streambeds, or low-lying ground that appears harmless in dry weather can flood any time if we receive too much rain. Dewana stream flooding during spring is another hazard problem in the area, this problem may be finished after constructing the dam. Dewana flood has impact on its surrounding, especially lower reach to Diyala, local people saying that the flood some time reaches the bridge that constructed over it ,which has 60m length and 5m high. The Dewana name comes from its nature of dryness and flooding at different time. 99
CONCUSIONS AND RECOMMENDATIONS
.
CONCLUSIONS AND RECOMMENDATIONS 1. Conclusions: The geomorphological study of Dewana basin of Sulaimani Governorate of Kurdistan region reveals important points in relation to its geomorphic subdivision, evolution and application. These points include: 1. The methods that are introduced in this study (especially GIS-based analysis) can improve work efficiency and reduce the work load of researchers creating data base which can be easily updated on time, beside advantageous of accuracy. 2. The natural factors which control the geomorphic evolution of the basin are discussed and includes (in importance order): tectonic and structural controls, stratigraphy and lithologic characters of the exposed formation, and climatic factors (rainfall) which controls intermittent fluvial processes of the basin. 3. Morphometric analysis of the basin evaluates the linear, spatial and relief parameters of the drainage network and show that: -The basin is of 6th order and includes 4th and 5th order sub-basins of Chamy Gora and Chamy Wara Qarawagh. -Basin shape is elongated and strongly controlled by tectonic setting of the area where it is bounded by two anticlinal ridges: The Baranan mountain from the north east and Sagerma mountain from south west. - Low bifurcation ratio reflects intermittent climatic conditions and fluvial erosion. -High relief ratio of the basin resulted from active rill and gully erosion which reflect dominating fluvial erosion and differential rock resistance. -Longitudinal profile of Dewana stream shows that it does not reaches the equilibrium state and erosion is still active. - The general high drainage density of the basin indicates that the region is composed of impermeable surface materials, sparse vegetation and high mountainous relief. -Drainage patterns of the Dewana basin network dominated by dendritic, sub- parallel and Sub-trills system. 4. Geomorphological analysis and classification using different types of geological, topographic as well as satellite images supported by field investigation reveal the occurrence of five geomorphological units based on their origin. These units are: -Units of Structural origin -Units of Denudational origin 111
CONCUSIONS AND RECOMMENDATIONS
.
-Units of Structural-Denudational origin -Units of Fluvial origin -Units of Anthropogenic origin These units and their common landform groups were discussed in terms of geological and geomorphological interrelations. 5. The dominating geomorphological process in the area is fluvial erosion and sedimentation which developing the most common landforms of the basin. The other process includes mass wasting of different types, flooding, weathering and denudation 6. The impact of the geomorphologic environment on human activity of the Dewana basin’s community is evaluated and discussed in term of the operating geomorphic process and other natural factors. These impacts include: -Flooding hazards and management -Water resources evolution and management -Mass wasting process and its impact on slope stability, which include classification and mapping of slope classes in the area. -Relation of geomorphological environment to agricultural activities and irrigation project. -Other hazards such as flooding and soil erosion are discussed.
2. Recommendations: 1. Application of GIS technique should be emphasized in geomorphological study which will provide qualitative shift and it also gives the new possibility of more exact analysis and synthesis. 2. Topographic map scale 1:20,000 is found to be suitable and give more accurate in results in morphometric analysis of similar basins. 3. For future studies similar basin should treated as single basin with no further subdivisions to avoid mixed-up with lower order sub basins. 4. There are a lot of indications of strong neotectonic activities which encourage future detailed studies. 5. Geologic dating of some quaternary samples from alluvial fan and river terraces can be very helpful in evaluation quaternary geologic history as well as paleoenvironment analysis. 6. Slope hazards evaluation of the area can be greatly enhanced by adding directions to the different inferred slope classes.
111
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التحليل الجيومورفولوجي بأعتماد تقنية نظم المعلومات الجغرافية لحوض ديوانة,محافظة السليمانية ,اقليم كردستان, شمال شرق العراق
رسالة مقدمة الى مجلس فاكلتي العلوم و تربية العلوم سكول العلوم في جامعة السليمانية كجزء من متطلبات نيل شھادة ماجستير علوم في علوم األرض
من قبل له نجه حسين عبداللة أحمد بكالوريوس جيولوجي ), (2005جامعة السليمانية
باشراف د .باسم عبدالخالق جعفر القيم بروفيسور
آيار٠٢12 ,
رجب ٤١33 ,
املستخلص أستخدمت لدراسة جيومورفولوجية حوض ( ديوانه ) املائي تقنيات حتليلية حديثة منها األستشعار عن بعد وتقنية نظم املعلومات اجلغرافية ) ( GISأضافة اىل منوذج األرتفاعات الرقمي ) ( DEMو جمموعة اخلرائط الطوبوغرافية و اجليولوجية و املرئيات الفضائية أضافة اىل الربجميات الرقمية املستخدمة يف التحليل والتوزيع املكاني مثل ) . ( Arc GIS 9.3
2
يقع حوض ديوانه يف حمافظة السليمانية و يف اجلزء اجلنوبي الغربي منها و مبساحة تبلغ ( 606كم ) و بني خطي طول ( 34° 34“ 00و ) 34° 43‘ ”00شرقا وخطي عرض ( 44° ”26 00و 04“ 00 ) 44°مشاال و حتيط به حافتان جبليتان طولية هي جبل برانان من اجلهة الشمالية الشرقية و جبل قرداخ من الناحية اجلنوبية الغربية . تناولت الدراسة طرقا حتليلية خمتلفة بهدف الوصول اىل حتقيق أهدافها وذالك بتحليل األشكال اجليومورفولوجية املختلفة ملنطقة الدراسة .من بني هذه الطرق ,التحليل املورفومرتي لشبكة الصرف حلوض ديوانه و ذلك لتحديد اخلصائص اهليد روجيومورفولوجية لشبكة التصريف النهري للحوض و ذلك بأستخدام جمموعتني من اخلرائط الطوبوغرافية لغرض مقارنة النتائج و حتديد دقتها .مت حسا
معامتات التحليل املورفومرتي الطولية و املساحية و
التضاريسية ,ثم مناقشة نتائج هذا التحليل و مقارنتها بالقيم النموذجية لغرض تقييم مرحلة التطور اجليومورفولوجي النهري للحوض . أوضحت الدراسة املورفومرتية للحوض انه حوض من املرتبة السادسة و ذو كثافة تصريف و فرق تضاريس عالي القيم مما يدل على بطىء انتقال املياه السطحية اىل الشبكة الرئيسية .وبالتالي تتعرض اراضيه للفيضانات و انهيارات السفوح و التعرية الشديدة عند هطول األمطار الغزيرة .شكل احلوض طولي األمتداد ومنط التصريف الرئيسي يرتاوح بني الشجري و شبه املتوازي و الشعاعي الذي يعكس قوة تاثري العامل الرتكييب والصخري على منط و نظام التصريف املائي للحوض . التحليل و املسح اجليومورفولوجي للحوض أفرز عند اعداد خارطة جيومورفولوجية تضم مخسة وحدات جيومورفولوجية رئيسية على أساس األصل و النشأة وهي : وحدة األشكال الرتكيبية األصل ,وحدة األشكال التعروية األصل ,وحدة األشكال الرتكيبية -التعروية وحدة األشكال النهرية األصل و وحدة األشكال الناجتة عن نشاطات األنسان .مت مناقشة هذه الوحدات و األشكال اجليومورفولوجية و وصفها بالتفصيل مدعوما باملتاحظات احلقلية و القياسات امليدانية للمنطقة .كما مت ربط هذه األشكال و نشأتها بالعمليات اجليومورفوليجية السائدة يف منطقة احلوض و اليت تقع على رأسها عمليات التعرية والرتسيب النهري .و لوضع نتائج هذه الدراسة موضع التطبيق مت مناقشة تأثري هذه املظاهر و العمليات على النشاطات البشرية لسكان حوض ديوانه وعرض املخاطر اجليومورفولوجية اليت تشكل األنهيارات السطحية من ختال تصنيف أنواع السفوح و درجاتها وكذلك الفيضانات و تعرية الرتبة .كما مت تقييم أدارة املوارد املائية للحوض من ختال مناقشة أثر العامل اجليومورفولوجي على النشاطات الزراعية و مشاريع الري .
ثوختة
لةم ليَكوَلَينةوةيةدا هةردوو زانستى هةستثيَكردن لةدوورةوة و سيستةمى زانياريى جوطرافى بوَ تويَذينةوةى جيوَموَرفوَلوَجى موَذى ( ئاوز َيلَى) ئاوةرِوَى ديَوانة ,ناوضةى سليَمانى ,هةريَمى كوردستان ,باكوورى خوَرهةالَتى عيَراق بةكارهيَنراوة .موَذى ديَوانة دةكةويَتة نيَوان هةردوو ه َيلَى دريَذى (45o14’00”, 45 o43’00”) Eو هةردوو ه َيلَى ثانى (35o03’00”, 35o26’00”) Nكة رِووبةرى نزيكةى 606كيلوَمةتر دووجا دةبيَت .ئةم ناوضةية لة باكوورى خوَلرهةالَتةوة بة شاخى بةرانان و لةباشوورى خوَرئاواشةوة بة شاخى قةرةداغ دةورةدراوة. ويَنةى داتاى سةتةاليتى لة دوورةوة هةست ثيَكراو و ويَنةى ديَم لةطةلَ نةخشةكانى توَثوَطرافى و جيوَلوَجى و ثيَكهاتن ,ئ ةمانة و كارى مةيدانى بةكارهاتووة بوَ طةيشنت و دةستكةوتنى شيكارى و ثوَليَن كردنى جيوَموَرفوَلوَجى ناوضةكة. تويَذينةوةكة لة بنةمادا لةسةر دوواليةن كاردةكات ,يةكةميان برِيَيت يان ضةنديَتيية و دووةميان وةسفيية (باسكردن) .بوَ هةردوو بنةماكة رِيَطا و داتاى جياواز بةكارهاتووة لة ثيَناو طةيشنت بة ئاماجنةكانى تويَذينةوةكة .ثروَطرامى Arc GIS 9.3لةثيَناو بةدجيت كردن و ويَنةكيَشانى داتا شويَنييةكانى شيكاريية جياوازةكان بةكارهيَنراوة. شيكارى وردى موَرفوَميرتى بوَ موَذةكة ئةجنامدراوة ,ئةمةش لةرِيَطةى بةكارهيَنانى هاوكوَلكة جياوازةكانى جيوَموَرفوَلوَجى و هايدروَموَرفوَلوَجى ئةويش بة ئةذماركردنى شيَوازةكانى توَرِيى لة دوو سيَتى نةخشةى توَثوَطرافييةوة .طشت كوَمةلَةى هاوكوَلكةكانى موَرفوَميرتى بةكارهاتووة وةك ه َيلَيى و هاوكوَلكةكانى هةلَةت و هةوايى .ئةجنامةكانى شيكارى موَرفوَميرتى خراوةتة ذيَر باس و طفتوطوَكردن و بةراوردكارييان لة نيوَانداو لةطةلَ نرخة ستانداردةكاندا بوَ كراوة ,ئةويش بوَ نرخاندن و هةلَسةنطاندنى طةشةكردنى جيوَموَرفى رِوبار لةم موَذةدا .توَذينةوةكة ئةوةى دةرخست كة موَذى ديَوانة لة جوَرى ئاوةرِوَى ثلة شةشة, كةبة شيَوةيةكى رِيَذةيى نرخى ضرِيى ئاوةرِوَ لةطةلَ نرخةكانى هةلَةتى موَذةكة بةرزن .ئةمةش ئةوة دةردةخات كة ئاوى سةرزةوى بةكتوثرِى و لةناكاو لةموَذةكةدا لةدةست ناضيَت ,ئةمةش الفاو دروست دةكات و رِامالَينى ضةمةكان و كةظرةخزىَ بةرهةم ديَنيَت .لةسةر بنةماى رِيَذةى دريَذى و رِيَذةى خرِيى موَذةكة, ئةوة موَذةكة شيَوة دريَذكوَلةية ,كةئةمةش ثةرضدانةوةى كوَنرتوَلَى بةهيَزى ثيَكهاتنة لة سةر موَرفوَلوَجى موَذةكة .شيَوازى ئاوةرِوَى زالَ لة موَذةكةدا شيَوة درةختيي ونيمجة تةريب و كةثريية ,كة ثةرضدانةوةى كوَنرتوَلَى بةهيَزى ثيَكهاتنة لةطةلَ رِةوشتةكانى ثيَكهاتةى كةظريى جياوازى كةظرةكانى موَذةكة. ئةجنامدانى نةخشةى جيوَموَرفوَلوَجى ورد و ثوَليَنكردنى دروستى موَذةكة لةسةر بنةماى بنةضة بوَ ديارى كردنى كوَمةلَةكان ,ئةوة ثيشان دةدات كة ضةند طروثيَك لة شيَوةى خاك هةية كة دابةش كراون بوَ ثيًنج يةكةى سةرةكى .ئةم يةكانةش بريتني لة :يةكةكانى بنةضة ثيَكهاتنى ,يةكةكانى بنةضة رِامالَينى, يةكةكانى بنةضة ثيَكهاتنى -رِامالَينى ,يةكةكانى بنةضة رِوبارى و يةكةكانى بنةضة مروَيى .ئةم يةكانة لةطةلَ لقة وردةكانيان لةسةر نةخشةى 00000000ديارى كراوة بوَ ئةوةى بالَوبوونةوةى ورد و ثةيوةندى نيَوان شيَوة جياجياكانى خاك ثيشان بدات.
طفتوطوَكردن لةسةر ئةم يةكانةو باسكردنى شيَوةكانى خاك لةاليةنةكانى جيوَلوَجى و توَثوَطرافى و توَرِى ئاوةرِوَ و كردةكانى دروستكةرى جيوَموَرفى ئةجنامدراوة .كردةى دروستكةرى جيوَموَرفى زالَ لة سةرتاسةرى موَذةكة بريتيية لة رِوباريى كة هوَكارى دروست بوونى شيَوة جياجياكانى خاك و يةكةكانة ,وةك نيشتووى وشكة دوَلَ و الفاوة دةشت و ثرِكةرةوةى دوَلَ و تةالنى رِوبار و نيشتووى ثانكةيى و كةندرِةكان و رِووتةن. كةشكارى و رِامالَينى بةهيَز شيَوةى وردى ئةم شيَوة خاكانةى ديارى كردووة. كاريطةرى دياردة وكردة جيوَموَرفوَلوَجييةكان لةسةر ضاالكي مروَيى لة موَذى ديَوانة نرخيَندراوة ئةويش بةمةبةستى ثيشاندانى رِوَلَى ئةم جوَرة تويَذينةوانة .ليَكدانةوة بوَ ناوضة مةترسيدارةكانى موَذةكة ئةجنامدراوة كة ونبوونى بارستة كاريطةرى لةسةر ليَذايى مامناوةند و تيذ هةية .جيَطرييى ليَذى لةرِيَطةى نةخشةسازى بوَ كوَمةلَةكانى ليَذى نرخيَندراوة .ليَذيية ناجيَطريةكان ثةيوةسنت بة زجنرية شاخةكان كة سنوورى باكوورى خوَرهةالَت و باشوورى خوَرئاواى سنووردار كردووة .هةنديَك بابةتى ترى وةك الفاو دروست بوون و كارطيَرِى سةرضاوةكانى ئاو و ثالنى ئاوديَرى و رِامالَينى خاك طفتوطوَى لةسةر كراوة و ليَكدانةوة و نرخاندنى لة بةر رِوَشنايى ئةجنامةكانى شيكارى جيوَموَرفى و داتاى بةردةست بوَ ئةجنامدراوة.
شيكارى جيوَموَرفوَلوَجى ثشت بةست بة سيستةمى زانياريى جوطرافى بوَ موَذى ديَوانة ,ناوضةى سليَمانى ,هةريَمى كوردستان ,باكوري رِوَذهة الَتي عيَراق
نامةيةكة ثيَشكةش كراوة بةئةجنومةنى فاكلَيت زانست و ثةروةردة زانستةكان سكولَي زانست لة زانكؤي سليَماني وةك بةشيَك لة ثيَداويستيةكاني بةدةستهيَناني برِوانامةي ماستةري زانست لة جيوَلوَجي
لةاليةن لةجنة حسني عبداللة أمحد بةكالؤريؤس لة جيؤلؤجي (,)5002زانكوي سليماني
بةسةرثةرشيت د .باسم عبداخلالق جعفر القيم ثروَفيسوَر
ئايار ٠٢25, 5125
جوَزةردان,
