UNIT – I : ECOLOGICAL CONCEPTS AND NATURAL RESOURCES Ecological Prospective An ecosystem consists of all the organisms living in a particular area (such as viruses, bacteria, fungi, plants and animals) as well as all the non-living, physical components of the environment (such as air, soil, water and sunlight) with which the living organisms interact. In other words we can say that an ecosystem is biotic assemblage of plants, animals and microbes with that of the abiotic components (physico-chemical environment).

The functioning of living systems and of their interactions with the environment, is the essential background of ecological concept and natural resources. The biotic components of the ecosystem are classified into two groups based on their system of acquiring energy and nutrients for their survival- i.e. autotrophs and heterotrophs. Autotrophs acquire energy from the solar radiation by the process of photosynthesis and nutrients from the soil and so, they are self-nourishing (i.e. green plants and some algae). These are also otherwise termed as producers. While, heterotrophs or consumers (i.e. all animal species and micro-organisms) acquire their energy by ingesting other organisms.

Natural living systems supply a wide range of indispensable and irreplaceable services to humanity that support our life on earth. These include direct resources, i.e. building materials (wood), food, medicines, clothing materials, etc. and functional services like maintenance of appropriate mixing of atmospheric gases, generation and preservation of soils, disposal of wastes, restoration of systems, control of pests, cycling of nutrients and pollination of crops. 1

Thus, not only is humanity totally dependent on the living environment but the integrity of the planet is itself dependent on the maintenance of the natural environment and on the interaction between the living organisms and the physical/chemical components of the earth.

Value of Environment Natural resources may be renewable, non-renewable or abstract. Renewable Resources

Non-renewable Resources

Abstract Resources

Energy from the sun, biological & biogeochemical cycles ( water and energy, hydrological and carbon cycles). At a more immediate level, renewable resources include forests that have been selectively cut down and replanted; animal and plant populations that have been properly managed by controlled hunting, fishing and collecting; and water with controlled inputs that can be readily recycled and reused.

Fossil fuels, minerals,topical hard-woods that are not replaced and rare animals or plants that are haunted or used in an uncontrolled manner. These include animals, plants and natural landscape as part of the “countryside” used for recreation and tourism activities such as bird watching, hiking(going for a long walk in the country side for pleasure), seight-seeing, etc.

The biotic diversity of the living systems must be viewed as a common property resource for all mankind. In this today’s world, the common property resources include scenic landscapes (areas having attractive sceneries), wilderness areas (desert or any natural land which is not used by people), migratory animals (fish-whales, birds and animals that migrate from one area to another in particular seasons for their breeding or finding new feeding grounds), biodiversity (existence of a wide variety of plant and animal species living in their natural environment), clean air and water.

Environmental Auditing We have to put specific values on economic considerations of various bio-diversities present in this total environment by making environmental audits, i.e. listing of all the available resources of a particular area. For example, the number of species presently known to science is about 1.5 million where as the estimation of global diversity made by various scientists says that there are about 20 – 30 million species which are not yet been properly documented. 2

Hence, to have a proper audit of biodiversity, we would need to examine the known value to mankind of the existing species and then estimate the unknown value of those new species and finally, extrapolate the total value of the particular environment ( kept under study), by including all “still to be discovered” species and their “yet to be discovered” values. The uses of the living environment may be of direct or indirect values but we will take into consideration of some direct uses which include foodstuffs, medicines, industrial and commercial products and tourism & recreation.

Foodstuffs : We get our food from the cultivated plants or domesticated animals. Till date, we are using only 20 major crop species as our plant food and a very small number of domesticated animal species as meat excluding sea food which caters only 10% of the total food requirement. This dependence on a very small number of domesticated animal and plant species for our food supplies is a result of historical chance rather than design. Many wild plants and animals have great potential as human food sources. For example, Indonesians make use of near about 4000 native wild plants in their diet out of which a very few plants have been explored for potential domestication and culture. Likewise, the people of Papua – New Guinea do consume 250 varieties of fruits out of which only 1/4th of the varities have been cultivated. The inhabitants of Brazilian rainforest consume the fruit of a palm tree called “Milpesos”(Family- Jessenia bataua) whose protein content (amino acid analysis) was found to be equivalent to that of prime beef and 40% higher than the biological value of Soya bean protein. Such plants of high protein content fruits should be planted in lowland tropics (low latitude tropical countries - Latin America, Africa, India, and Indonesia where worm weather year round) where high protein sources are especially desirable. Those, few crops that we do currently cultivate are derived from a very small number of plants, sometimes a single plant. They therefore, have a very reduced genetic use which may result in low disease resistance, inability to grow in a wide range of climatic conditions and so on. Likewise, the domestic stocks of animals are also derived from a small population of animals. We know that cow is domesticated worldwide as a source of animal protein but in Venezuela (a country on the northern coast of South America - most urbanized country in Latin America), attempts have been taken to domesticate the capybara – a large native rodent, as an alternative to the cow, whose yields have been found to be superior to that of the cows under similar conditions. [ Capybara is the largest rodent in the world. It is not a threatened species. It is hunted for its meat, hide and also for a grease from its thick fatty skin which is used in the pharmaceutical trade ]

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Medicines : Wild plants and animals are of important uses in medicines which cover more than half of the total prescription drugs. Example : The wild plant Catharanthus roseus (Madagascar periwinkle) contains about 130 terpenoid indole alkaloids out of which the main marker compound is Vinblastin which is used as an anticancer drug since last 40 years. The plant is now a days wildly cultivated though it profits little from the exploitation of its flora. Likewise, there are millions of possibly useful substances available in living organisms which are yet to be clinically proven to have antidisease activities. At the moment, there is increasing interest in Coral reef organisms [Coral reefs are diverse underwater ecosystems held together by calcium carbonate structures secreted by corals. Coral reefs are built by colonies of tiny animals found in marine waters that contain few nutrients] as a source of antibiotics. Recently, the researchers have isolated a potent antibiotic, called transitmycin (an yellow pigmented compound), from the coral reefs which may lead to superior treatments in tuberculosis and HIV within next 10 years. The rainforests (forests characterized by high rainfall, with annual rainfall between 250 and 450 centimetres) also carry a large number of medicinal plants which are yet to be explored but the rainforests are also source of dreadful diseases where HIV and Ebola viruses (EBOV) are found which are mostly sourced from the monkeys living in the rainforests.

Industrial and Commercial Products : Various industrial and commercial products provided by the environment include wools, sheep skins, feathers, etc. from animals; cotton, sisal, jute, rubber, waxes, resins, oils, gums, tannins, etc. from plants and many others including fossil fuels (coal, petroleum,natural gases, kerosene, propane, etc.) and minerals (solid and inorganic naturally occurring substances – there are over 4900 mineral species). The most commercially valuable of all products that we obtain from plants are woods, especially whitewoods (trees with light-coloured wood, such as the tulip tree, basswood, and cottonwood) where as, hardwoods are slow growing trees which are harvested from natural forests, particularly from tropical forests. Now a days most tropical forests are completely cut down without having any further replanting schemes.

Tourism & Recreation : In many cases, the land is more valuable to preserve wild lives than to use the land for cropping purpose. The economic yield from the tourists who come to see a lion in Amboseli National Park (Kenya) is equal to the income from a herd of 3000 cows. Activities such as bird watching and fishing are enjoyed by millions of people worldwide. In the United States itself, there are 8 million bird watchers and 30 million anglers [Angling is a method of fishing by means of an "angle" (fish hook)]. Several billion dollars are being spent each year in America on these recreation and tourism activities. 4

Biotic Components Biotic components are the living things that shape an ecosystem. A biotic factor is any living component that affects another organism, including animals that consume the organism in question, and the living food that the organism consumes. Each biotic factor needs energy to do work and food for proper growth. Biotic factors include human influence. Biotic components are contrasted to abiotic components, which are non-living components of an organism's environment, such as temperature, light, moisture, air currents, etc. Remember the abiotic factors by SWATS. Soil, Water, Air, Temperature, and Sunlight. Biotic components usually include: 

 

Producers, i.e. autotrophs: e.g. plants, they convert the energy [from photosynthesis (the transfer of sunlight, water, and carbon dioxide into energy), or other sources such as hydrothermal vents] into food. Consumers, i.e. heterotrophs: e.g. animals, they depend upon producers (occasionally other consumers) for food. Decomposers, i.e. detritivores: e.g. fungi and bacteria, they break down chemicals from producers and consumers (usually dead) into simpler form which can be reused.

Producers : These are the most important components of ecosystems. Producers of an ecosystem may be defined as those individuals who depend directly on the abiotic component for their survival and production of nutrients. Green plants are the chief producers of a negotiable energy source in the nature which could be utilized by all other living organisms. By their photosynthetic activity, the green plants trap the solar energy and convert it into chemical energy which is available in their body tissues. Apart from the green plants, photosynthetic and chemosynthetic bacteria are the two types of autotrophic organisms in the ecosystem. Consumers : The living components of the ecosystem which depend on producers for their nutrition are called consumers. All the animals and certain plants are included in this category. There are different types of consummers, i.e. Primary consumers, Secondary consumers, Teritary consumers, and Parasites and saprophytes. Primary consumers All the herbivorous animals like rodents, cow, elephants, deer, goats etc, which directly consume the plants are called primary consumers. Among the aquatic animals, certain kinds of fish, crustaceans, molluscs etc which survive on phytoplankton are also primary consumers. According to Elton (1939), herbivorous animals are key industry animals, because all other animal's life is dependent on these primary consumers. Secondary consumers Carnivorous and omnivorous animals belong to this category. These animals predate on herbivorous animals. Omnivorous animals eat herbivorous animals as well as plants. Sparrow, Crow, Fox, Wolves, Cat, Dogs, Snakes etc belong to this category.

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Tertiary consumers They are strictly carnivorous animals that prey upon carnivores, herbivores, and omnivores. Lions, Tigers, Vultures etc are regarded at tertiary consumers. Parasites Plants and animals that infect other living components of the ecosystem and survive on them are regarded as parasites. Various types of fungi, bacteria and a few flowering plants are parasitic. Several protozoans, insects and nematodes are also parasitic. Decomposers : These are also called transformers as they transform organic compounds into inorganic or simple compounds. Saprophytic fungi and bacteria belong to this category. They act upon the dead bodies of plants and animals and decompose them to their elemental stage. These in turn can be used by producers for their existence and photosynthetic activity. The decomposers occupy a pivotal place (of central importance) in the ecosystem as they indirectly support the producers. Herbivore – Latin, herba meaning a small plant or herb and vora, from vorare, to eat or devour. Carrivore - Latin, caro meaning 'meat' or 'flesh' and vorare meaning 'to devour'. Omnivore - Latin, omnes, omnia, meaning "all" or "everything" and vorare meaning "to devour".

Levels of Organisation in Biotic Components of the Environment One of the major part of ecology is that everything in the global environment is connected to everything else, so that any change in one component affect many others over both space and time. This is clearly marked when we consider the nested levels (systematic arrangement) of the organisational hierarchy [A hierarchical organization is an organizational structure where every entity in the organization, except one, is subordinate to a single other entity. This arrangement is a form of a hierarchy/pyramid] of ecological systems on earth.

Pyramid of different levels of Organisation 6

Individual : These have physiological functions and respond to environmental conditions. Individual organisms belong to a species that includes all the individuals potentially able to interbreed with one another and produce fertile offspring. Population : Consists of a group of individuals of the same species living in a particular area at the same time. Each population is genetically distinct to some degree from other separate populations of the same species. Community : Populations of different species live together, many interacting with each other , forming a community, e.g. in a pond – a natural community of plants, animals and microbes form a distinctive living system. These interactions lead to formation of food webs, a hierarchy of who eats who. Ecosystem : This comprises both the living (biotic) and non-living (abiotic) components of an area – a combination of the community and its physical and chemical components of the local environment. Hence, the major part of this ecosystem is the strong interaction between biotic and abiotic components and the major processes which take place at this ecological level are energy flow and nutrient cycling.

[ Dynamic Nature of the Ecosystem due to interactions and interdepence of various Components ] Biomes : Where environmental conditions (e.g. climate) are similar in different parts of the country or on a large scale in different parts of the world, the habitats (vegetation types) and communities are often similar. Biospheres : It is the highest organisational level – that part of the earth and atmosphere where life exists. It includes the surface layer of land, oceans, the sediments at the bottom of water bodies and part of the atmosphere occupied by life. 7

Ecosystem Processes : We know that ecosystem consists of a series of interacting biotic and abiotic subcompartments and two important processes which act as major linkage pathways between these two sub-compartments, i.e. energy flow and nutrient cycling

These two processes are essential for the survival and maintenance of the biotic environment. Energy Flow One of the most important interactions between living organisms and their environment is the provision of food. The food not only supplies energy for survival but also, it helps in construction of body tissues and gamates for reproduction of the species. On earth, the ultimate source of energy for life is solar radiation or light and this is eventually reradiated back to space as heat. It is the change from non-random energy (light) to random energy (heat) that allows the work to be done and this drives the life on earth.

Non-random Eenrgy (Light)

Random Energy (Heat) Chemical Energy

//////////////////////////////////////////////////// Earth Surface In ecosystems, a proportion of light energy is converted into chemical energy which is the energy currency of the living systems. This energy is stored either in living or in dead organic matter (cabon-based compounds). In living organisms, some organic matter is converted to a chemical complex, called ATP which itself is broken down during metabolism to release the stored chemical energy and allow the work to be done (i.e. locomotion, cell division, biochemical reactions, etc.). In the environment, there are two sources of energy, i.e. autotrophic and heterotrophic. Autotrophic production of energy rich organic matter is carried out within the ecosystem by green plants in the presence of light by the process of photosynthesis. On the other hand, heterotrophic energy source is one where the chemical energy is imported as organic matter which originated from primary production in some other ecosystem. Example : In a heavily shaded forest stream, the dead leaves entering the stream from the

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surrounding catchment are carried down from upstream and this imported organic matter forms the major energy source on which the stream community is built. Hydraulic Analogy of Energy Flow Through An Ecosystem :

Photosynthesis All green plants create their own food through a complex series of chemical reactions driven by solar radiation using the pigments, called chlorophylls.By this process,energy-rich organic molecules (glucose) are synthesized. Chlorophyll + Enzyme 12H2O + 6CO2 + 709 K Cal. (from light)

C6H12O6 + 6O2 + 6H2O Carbohydrate (to air)

This process is carried out only in the day light in the green leaves and even in some green stems of the plants, algae and cyanobacteria. Such organisms are called “photoautotrophs”. The glucose produced by the plants is simply stored as energy-rich substance in the form of starch or be combined with other sugar molecules to form carbohydrates like cellulose, used in plant cell or tissue construction. Plants also need some inorganic substances like nitrogen, phosphorus, magnesium and iron which are obtained from the soil.

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When any organism requires energy, essentially the reverse reaction to photosynthesis, called respiration takes place. In this process, the glucose molecule is broken down in the presence of oxygen to yield carbon dioxide, water and energy. Metabolic enzymes C6H12O6 + 6O2 CO2 + H2O + Energy for work and maintenance Photosynthesis maintains atmospheric oxygen levels and supplies all of the organic compounds and most of the energy required for life on earth. Although photosynthesis is performed differently by different species, the process always begins when energy from light is absorbed by proteins, called “reaction centres” that contain green chlorophyll pigments. In plants, these proteins are held inside the organelles, called chloroplasts, which are most abundant in leaf cells, while in bacteria, these are embedded in the plasma membrane. The production of organic matter by plants is called Primary Production. The Gross Primary Production is the total amount of chemical energy (or biomass) stored by plants per unit area per unit time. Since plants require energy for synthesis of organic matter and function of the plant itself, some of the gross primary production is used in the process of respiration. The remaining production, Net Primary Production, can then be used in plant growth and reproduction. Hence, Net Primary Production = Gross Primary Production - Respiration As of now, the average energy capture by photosynthesis globally is approximately 130 terawatts [ 1 terawatt = 1 trillion watts (1012 watts) ] which is about six times larger than the current power consumption of human civilization. Photosynthetic organisms also convert around 100 – 115 thousand million tonnes of carbon into biomass per year. Food Chains & Food Webs : Autotrophs make their own food whereas heterotrophs cannot and so, they are directly or indirectly dependent on producers as the primary source of food. Decomposers or saprobes (certain bacteria, fungi and yeast) feed by decomposition of dead organic matter. Animals feed by ingesting readymade organic food stuffs from living or dead organisms (carbohydrates, fats and proteins). The chemical energy produced by the primary producers and the nutrients used by the plants to build plant tissues are passed up through a chain of consumers – the food chain – providing each link in the chain with energy and nutrients.

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Each consumer population uses the food energy consumed to live and respire and the remaining energy can then be used to help produce new biomass by growth and reproduction. This production of new biomass by the consumer population is called secondary production. Secondary production of one consumer population then becomes a potential food and energy source for another and in this way, the food chain continues. Ecosystems consist of a myriad (a large number of) series of such food chains. Species populations at each link in the various chains are grouped into trophic levels. First Trophic Level Primary producers (Grazing food chain) Second Trophic Level Primary consumer (Herbivores feeding on the plants) Third Trophic Level Secondary consumer (Predator or parasite feeding on herbivores) Fourth Trophic Level Tertiary consumer is a predator population feeding on the precoding consumer level (Predator eating predator). The process continues……………………… Plants and animals also produce waste organic matter (e.g. leaves and faeces respectively) and this dead organic matter becomes a food source for further groups of consumer organisms, detritivores(earthworms,woodlice, millipedes, etc.) and decomposers(bacteria and fungi). Food chain A food chain is the hierarchy of consumption of food from Sun to Plant to Herbivore (1st level consumer) to carnivore (2nd and higher level consumers). It acknowledges only one single string of connected plants/animals. Food Web A food web is an inter-linkage of series of food chains showing various different plants and animals in an ecosystem in relation to each other. It encompasses many consumers of each different level, acknowledging that one predator may eat several different kinds of prey, and that one kind of prey may be eaten by several kinds of predators. There are many food chains within a food web, and one creature is not necessarily at the top of the hierarchy. Decomposition and Nutrient Cycling : During flow of energy in grazing food chains, there is movement of nutrients (amino acids, minerals,sugar, salts and vitamins) from one organism to another during feeding. As organic molecules of food are broken down by respiration and metabolism, so chemical constituents are either incorporated into the body of the organism or released back to the environment when the organism sheds body parts or dies.

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Decomposer Food Chain Energy Flow

Each link in the chain extracts nutrients and energy from the organic matter and looses energy through respiration before passing on the remaining organic matter to the next link in the food chain. On land, most decomposition takes place in soil whereas in aquatic ecosystems, it occurs in sediments at the bottom of water bodies. Decomposer or detritus food chains are based on detritus (dead organisms, leaves, undigested and partially digested faecal matter and excreted waste products from metabolism) as opposed to living plants in grazing food chains. The initial consumer of this food source, the detritivores ingest and partially digest the detritus, breaking the organic matter to some degree and after extracting some energy, egesting the remainder in faeces and excretory wastes as smaller particles. These wastes are then utilized by the next detritivore population in the chain, which repeats the process. The final breakdown of the organic matter to its original inorganic constituents of carbon, nitrogen, phosphorus, etc. is carried out by bacteria (true decomposers). The importance of decomposition is that the complex organic molecules in the original detritus are gradually broken down to much simpler constituents and inorganic molecules (like nitrates and phosphates) as the material moves through the decomposer food chain. These are then incorporated into the soil or sediments or dissolved in water, where they become the nutrients available for reuse by the plants. Thus, there is a recycling of nutrients within the ecosystem.

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Diagrammatic Representation of Energy Flow & Nutrient Cycling

Solar Energy

Soil

Rain

R R

Producer

Producer

D E C O M P O S E R

R Primary Consumer

R Secondary Consumer

R

D E C O M P O S E R

Tertiary Consumer Energy Flow

Nutrient Cycling

HYDROLOGICAL CYCLE : Hydrology is the study of water and its movement along its various pathways within the cycle comprising atmosphere, rivers, oceans, soil and water containing rocks. Applied hydrology is the use of engineering assumptions to quantify the soil and river responses to rainfall events. Hydrological cycle is a never-ending continuous process of water evaporation and precipitation. Water evaporates in a large extent from the oceans and to a lesser extent from the land surfaces. Approximately, seven times more evaporation of water from the oceans takes place in comparison to land surfaces. The evaporated water or water vapour rises into the atmosphere until the lower temperatures cause it to condence and then precipitate in the form of rain.

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The global annual water balance relative to 100 units of land precipitation is detailed below in water balance diagram.

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Clouds over Ocean Evaporation from Oceans 424 424 Evaporation From Oceans

Loss to Land Clouds

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Gain to Land Clouds

Precipitation to Oceans 385 385 Precipitation to Oceans

Oceans

Clouds over Land

Precipitation to Land 100

Evaporation over Land 61

100

61

Precipitation to Land

39 Inflow

Evaporation over Land

Land

For Landmass : Input ± Change in storage = Output For Oceans : Precipitation + Inflow = Evaporation

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The oceans contain 96.5% of total water while the rivers occupy only 0.0002%. The usable fresh water present in underground is about 30.1% while the soil moisture content is only 0.05%. Components of Hydrological Cycle :

Atmosphere

Atmosphere

Interception

Evaporation

Depression Storage

Precipitation rain/snow/sleet/ hail

Water on Surface

Interception

Overland Flow

Evaporation

Reservoir Storage

Interflow

Infiltration

Evapotranspiration

Root Zone Storage

Channel Flow

Channel Storage

Ocean Ground water Storage

Ground water Flow

Interception is the evaporation of water from the outer surface of the leaves during and after rainfall. Transpiration is evaporation of water through foliage. Some water may become overland flow and eventually reach a stream or river and be discharged as surface runoff. It may infiltrate into the soil and flow horizontally as interflow. A significant volume of precipitation may be returned to the atmosphere through evaporation from water bodies and evapotranspiration from vegetated surfaces. Evaporation - The conversion of liquid water from lakes, streams and other water bodies of water to water vapour. 15

Transpiration – It is a process by which water is emitted from plants through stomata. It occurs predominantly at the leaves while the stomata are open for the passage of CO2 and O2 during photosynthesis. Because it is often difficult to distinguish between true evaporation and transpiration, the hydrologists use the term “evapotranspiration” to describe the combined losses of water due to transpiration and evaporation. Precipitation is the primary mechanism by which water is released from the atmosphere. As water falls to the earth’s surface, the droplets run either over the ground into the streams and rivers( surface run-off, overland flow or direct run-off ), or move vertically through the soils to form ground water (infiltration or percolation).

RAIN FALL – RUN OFF RELATIONSHIP

When rainfall occurs on the land surface, it may follow different routes depending on the topography ( study of detailed description of the surface features of a region ) and soil conditions as well as soil moisture content. Whether the rainfall converts to surface runoff or infiltration, depends on principally two factors, i.e. land slope and infiltration capacity. On steeply sloping areas, surface runoff is more likely to occur, while infiltration legs behind. Surface runoff is also called as “overland flow”.

WATER BALANCE OR WATER BUDGET It is the accounting of water for a particular region or even for the earth as a whole. It is the quantitative account of the hydrological cycle. The input to this cycle is precipitation, either as rainfall, snow or sleet. The precipitation is distributed as surface runoff, evaporation, infiltration to the unsaturated zone, changing its storage and deep percolation to the saturated zone. The equation for water balance is; P = R + E ± ΔS ± ΔG Where, P – Precipitation (mm / Day) R – Surface runoff E – Evaporation ΔS – Change in soil moisture status ΔG – Change in ground water status

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ENERGY BALANCE OR ENERGY BUDGET The energy received at the earth’s surface is the solar radiation, some of which is reradiated to atmosphere and some penetrates the earth surface. The earth also reradiates some of the solar energy. Energy balance or energy budget is the accounting of the distribution of the incoming solar radiation from space, through the atmosphere and onto the earth’s surface of land and ocean. The quantity of radiant energy remaining at the earth’s surface is known as the net radiation, Rn. The energy budget is expressed as; Rn = LE + H + G + Ps + M Where, Rn – Specific flux of the net incoming radiation (watts / m2 ) L – Latent heat of vaporisation & E – Evaporation H – Specific flux of sensible heat into the atmosphere G – Specific flux of heat into or out of the soil. Ps – Photosynthetic energy fixed by plants M – Energy for respiration and heat storage in a crop canopy

URBAN HYDROLOGY It is the study of relationships between urbanization and the natural water cycle. The rapid urbanization and growth of large cities with high rise and high density development at the centre and low rise in the periphery creates conflict between land and water. Water scarsity as well as wastage, disposal of wastes into water and pollution, death of aquatic species, associated with health and hygiene problems are quite common now-a-days. Hence, an integrated plan for water with rivers, canals, streams, wet lands and ground water coordinated with land use, water supply, storage, distribution, etc. is necessary. Hydrograph Response due to urbanization

Flow

Urban

( m3/sec ) Rural

Time 17

Urban hydrological cycle is an integral part of the ecological cycle which is based on biological, human and environmental criteria. Urban hydrology should be a component of regional environment to plan with defined objectives for sustainable water resource covering conservation, environment and development. This should include several components like; i) ii) iii) iv) v) vi) vii)

Study of papameters – physical, biological, human and environmental, supply and demand, projected need, sources, etc. Assessment of large dam, construction, upstream downstream development, etc. on urban water system. Regulation Control – control on ground water, water bodies, and wet lands. Interaction between urban water system with canals, streams, rivers, and other natural resources. Mechanism of pollution control, and water related disease. Method of disaster management, specially in coastal cities and also, removal of water logging and urban flooding. Actions regarding recycling of waste water, conservation of water, rain water harvesting (accumulation and deposition of rainwater for reuse on-site, rather than allowing it to run off. Its uses include water for garden, water for livestock, water for irrigation, water for domestic use with proper treatment), etc.

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