From Unsustainable to Sustainable development; Urban problems related to energy; Water conservation, rainwater harvesting, watershed management, Resettlement and rehabilitation of people; its problems and concerns. Case Studies; Environmental ethics: Issues and possible solutions; Climate change, global warming, acid rain, ozone layer depletion, nuclear accidents and holocaust. Case Studies; Wasteland reclamation; Consumerism and waste products; Environment Protection Act; Air (Prevention and Control of Pollution) Act; Water (Prevention and control of Pollution) Act; Wildlife Protection Act; Forest Conservation Act; Issues involved in enforcement of environmental legislation; Public awareness.
6. 1 Unsustainable to Sustainable development
Sustainable development is not really a new concept. This means living in harmony with the type completely recognition of the needs of most other species. It really is no just "the survival of the fittest", we must help even the weakest of the species to survive because each species has a role to experiment with that is ultimately beneficial to the planet earth and everything its population. Our forefathers preached us the need to coexist with the environment in a well-balanced manner. The needs of folks in different parts of the earth may vary, but our dependence on the Nature is similar. The main thing to remember is that we have only one earth of course, if we destroy it by our actions, our children won't have a spot to live.
The first comprehensive definition of sustainable development was given by the Brundtland Commission in 1987:
"Sustainable development is development that meets the needs of the present without compromising the power of future generations to meet their own needs. " [Brundtland, G (ed) (1987). Our Common Future: The World Commission on Environment and Development, Oxford: Oxford University Press].
Any development activity can be sustainable, if it's ". . a dynamic process which allows all people to realize their potential, and to improve their standard of living, with techniques which simultaneously protect and improve the Earth's life support systems". (Forum for the Future, Annual Report 2000).
In short, if we look after the comfort of the present generation only and don't think of the needs of the future generations, and we damage the surroundings by various development activities, these activities will be referred to as unsustainable. In taking every action, small or big, the possible damages to the environment must be given full consideration and the action should never leave behind a degraded environment. Technically, sustainable development is defined as a path of development where no permanent and irreparable damage is done to the environment and the resources are kept intact for the future generations. The earth has everything for every single generation, but it will depend on the proper use. The present generation may survive very well on the resources available, nonetheless they must also leave behind enough resources for future years generations. It's important a sustainable development path do not have any negative factor that is accountable for triggering adverse impacts on the surroundings. A sustainable development programme is friendly to the ecosystem in every respect and has the capacity to absorb abrupt changes of the present and the near future. Sustainable development in addition has a strong element of socio-political development. Thus, sustainable development programme will need to have equal concern for many parts of the society with a balanced economic development and environmental protection. The programme should have a log-term view of future consequences of any action taken today. In a nutshell, sustainable development is among the most cornerstone of development planning today and in addition has become a principal tool of negotiation in international aid packages to the countries.
The sustainable development can be broadly classified into three different types, viz. , environmental sustainability (no long term damage to the environment), economic sustainability (economy remains stable with equitable sharing of resources) and sociopolitical sustainability (maintaining social harmony and political stability).
Historical milestones
The Brundtland Commission, formally the World Commission on Environment and Development (WCED), known by the name of its Chair Gro Harlem Brundtland, was convened by the US in 1983. The commission was made to handle growing concern "about the accelerating deterioration of the human environment and natural resources and the consequences of this deterioration for economic and social development. " In establishing the commission, the UN General Assembly recognized that environmental problems were global in nature and determined that it was in the normal interest of most nations to establish policies for sustainable development. The Commission was asked to target mainly on the following:
To propose long-term environmental strategies for attaining sustainable development to the entire year 2000 and beyond;
To recommend ways that concern for the environment may be translated into greater co-operation among developing countries and between countries at different stages of monetary and social development and lead to the achievement of common and mutually supportive objectives which take account of the interrelationships between people, resources, environment and development;
To consider ways and means where the international community can deal more effectively with environmental concerns, in the light of the other recommendations in its report;
To help define shared perceptions of long-term environmental issues and of the correct efforts had a need to deal successfully with the problems of protecting and improving the surroundings, and a long-term agenda to use it during the coming decades.
The need to protect and enhance the human environment inside a common framework and principles led to the Brundtland Report and subsequently, the United Nations Conference on Environment and Development (UNCED), more commonly known as the Earth Summit, occurred in Rio de Janeiro, in 1992. This conference was designed to help governments to rethink economical development and find ways to avoid pollution and the destruction of natural resources. The conference documents included:
Rio Declaration on Environment and Development
United Nations Framework Convention on Climate Change
United Nations Convention on Biological Diversity
Statement of Forest Principles
Agenda 21
Agenda 21 and Sustainable Development
At the planet earth Summit in 1992, an agenda on worldwide sustainable development was formulated. This agenda, known as the Agenda 21, is a blueprint on how to make development socially, economically and environmentally sustainable into the next century. It addresses economical and development issues and the conservation and management of the world's resources. The implementation of Agenda 21 has been made the duty of Governments, non-governmental organizations (NGOs), industry and also the general public. Agenda 21 provides a global framework for tackling global environmental problems like climate change, ozone depletion, biodiversity loss, desertification and deforestation.
The Earth Summit was followed by a conference in Johannesburg, South Africa in 2002 where the stakeholders from international institutions and corporations to national, regional and local governments have accepted that the principle of sustainable development will be at the core of most policy making. A few of the areas highlighted by the Agenda 21 are:
(i) Combating Poverty. Poverty and environmental degradation are directly related to one another which is imperative for the governments that they need to focus on poverty alleviation to be able to protect the surroundings. The national programmes should aim at sustainable use of resources and really should enable the poor to make a living without destroying the surroundings. It is envisaged that the individuals must have a say in the development process and this local groups should be engaged in the look and execution of anti-poverty programmes. In this way, the people will become a celebration to sustainable development and environmental protection.
(ii) Changing Consumption Patterns. Agenda 21 demands an alteration in the existing patterns of production and consumption so that the damages to the surroundings may be minimized. For this purpose, the industrialized countries have been asked to experiment with a respected role. National programmes should give more emphasis to better production processes so that emissions and waste generation are brought right down to minimum. All processes of production and consumption should conform to the principle of sustainable development - i. e. no injury to the environment. The Governments should discourage all production processes that are not environment-friendly and should levy taxes on goods that are produced through such processes. The usage of eco-labels on appliances should be encouraged and efforts should be made to raise public awareness on energy efficiency and recycling of wastes.
(iii) Population and Human Health. The rapidly increasing population has generated much pressure on natural resources, employment, social and health services. Sustainable development is extremely hard if the populace is not appropriately controlled. Agenda 21 calls for the governments to look at measures that take into account the links between population dynamics and sustainability, and identify carrying capacities. Illness is usually a result of poverty, especially in developing countries. Agenda 21 recommends that each national health programme should give the introduction of basic health care facilities with focus on training of doctors, nurses and other personnel, strengthen immunization programmes to regulate communicable diseases, and provide specific healthcare measures for the most vulnerable groups, including infants, women and indigenous peoples.
(iv) Human Settlements. Migration to the urban centers has been continually increasing and the towns and cities are overcrowded with people. Slums have expanded and basic facilities such as way to obtain clean drinking water, sanitation and sewerage facilities, healthy living conditions, etc. , are becoming scarce. Traffic congestion, poor air quality, waste dumping and unhygienic conditions have multiplied generally in most cities. Agenda 21 calls for appropriate urban renewal projects and transportation strategies, the provision of access to land, and credit and low priced building materials for the poor. Migration to big cities can be reduced only by enhancing living conditions and employment opportunities in rural areas and Agenda 21 lays stress on the development of the rural areas.
(v) Atmospheric Protection. The atmosphere can be protected by reducing emissions to it. For this function, Agenda 21 demands action in the production sector, transport and industry, through the promotion and development of energy conserving programmes, regional energy plans, public-awareness campaigns of environmentally sound energy systems, and research into more fuel-efficient transport systems.
(vi) Ecosystems. Ecosystem conservation and protection is considered as a significant item in sustainable development. For this function, Agenda 21 calls for governments, business houses and NGOs to introduce programmes of afforestation, reforestation, and sustainable land use and water resource management. The education programmes should be reoriented towards environmentally sustainable resource management.
(vii) Sustainable Agriculture and Rural Development. While agriculture should yield enough food for the rising population, the farming practices shouldn't lead to land erosion, desertification and deforestation. Current methods of farming, particularly in developing countries, should be carefully examined and unhealthy practices should be discontinued. Agenda 21 urges the development of long-term land conservation and rehabilitation programmes, by encouraging people to invest for the future through land ownership.
(viii) Conservation of Biological Diversity and Management of Biotechnology. Habitat destruction, over-harvesting, pollution and introduction of foreign species are recognized as the main causes of loss of biodiversity. Agenda 21 demands governments to undertake national biodiversity assessment programmes and formulate strategies to conserve the prevailing biological diversity without further damage.
(ix) Protecting and Managing the Oceans and Fresh Water. Agenda 21 demands nations to build up policies, which address unsustainable fishing practices, the creation of marine protection zones, and the surveillance and enforcement of fisheries regulations. The agenda further requires that the National water management practices are integrated into economical and social policies. Agenda 21 sets 2025 as the realistic target date for ensuring universal water supplies, and also to develop low-cost services, which can be built and maintained at the community level.
(x) Managing Wastes. Agenda 21 calls for an international technique to manage the production and disposal of wastes, including hazardous waste, solid waste and sewage, and radioactive waste. Governments should encourage and assist industry in reaching cleaner production technologies, and promote changes in lifestyles, production and consumption, through recycling and fund public education initiatives. Countries, which generate nuclear waste, should adopt an integrated method of the safe management, transportation, storage and disposal of radioactive wastes.
(xi) Implementing Sustainable Development. All nations must make political, social and financial commitments to ensure that the Agenda 21 can be properly implemented and that necessary resources are available for the same. The Agenda asks international funding organizations including the International Development Association and the Global Environment Facility to help developing countries in meeting additional expenses in implementing all measures required for sustainable development. Developed countries should help promote the transfer of technology to developing countries.
It is essential to monitor the implementation of Agenda 21. Laws should be enacted to secure a balance between the needs for development and environmental protection. The main objectives will include: international standards in environmental protection considering the various situations and capabilities of individual countries; overview of all environmental laws making them more effective; and measures to avoid or settle international disputes.
Meeting the aims and objectives of Agenda 21 within the time frame established by the 1992 Earth Summit will pose great social, financial and technological difficulties, both for developing and developed nations. The development that has been witnessed during the 20th century has taken unprecedented changes to biodiversity, the atmosphere and global climate. These are to be reversed. The new challenge for today's society is to ensure that future development and the utilization of the Earth's resources is managed in a sustainable way, and atlanta divorce attorneys action, the grade of life is preserved for generations of the 21st century and beyond.
For sustainable development, human population growth should be controlled. Otherwise, no invention and development in science and technology will be able to prevent irreversible degradation of the environment and also to alleviate continued poverty in large elements of the globe. The natural and social sciences will be crucial in developing new options for limiting population growth, protecting the environment, and improving the grade of human life. These should be the perspectives in every short and long term planning for all governments so the challenges of today's and the future can be adequately addressed.
6. 2 Urban problems related to energy use
With massive urbanization occurring on a global scale, the state of the surroundings and human health in the cities of the world has turned into a prime concern. It is estimated that by the year 2025, over five thousand million people will be residing in the cities. Within the developing countries of the world, already more than 200 cities have populations of 1 million or more. Living in cities has many positive benefits, such as increased job opportunities and better usage of essential services and facilities. However, many environmental, health and development problems reach near-crisis dimensions in cities all over the world. Urban growth has exposed populations to serious environmental hazards and has outstripped the capacity of municipal and local governments to provide even basic amenities (water, sanitation, power) and essential health services. Millions of people in the urban areas of developing countries are living under life- and health-threatening conditions. Cities have a substantial impact on the broader hinterland and global environment and the fate of cities will have a significant influence on the fate of nations and of the earth.
Poverty and health
Despite the unprecedented creation of wealth worldwide before two decades, the quantity of people residing in absolute poverty keeps growing steadily. Poverty remains the main killer, with the indegent bearing a disproportionate share of the global burden of ill health. The poor live in unsafe and overcrowded housing, often in semi-urban and urban slums, with practically no access to safe water or to sewerage. These folks are also exposed to pollution, traffic and industrial and other risks at home, at the job or in their communities, much more than the wealthy people surviving in the same cities. They may have insufficient food that too of low quality from the idea of nutrition.
Even in rich countries, the indegent suffer worse health than do the better off. Children are particularly influenced - in the poorest parts of the planet, one in five children dies before his / her first birthday, mostly from environment-related diseases such as acute respiratory infections, diarrhea and malaria. Not only are children more heavily and frequently exposed to threats to their health in the environment, but they are also more susceptible to the ill effects on health. For instance, in america and elements of Europe, lead poisoning illustrates the unequal burden of risk borne by poor inner-city children, who will be more heavily exposed to resources of lead in and around the house and are also more affected by the toxicity of lead.
Energy consumption
Compared to the rural areas, people in towns and cities consume massive amount energy. For instance, the old kind of Indian houses were made of wood, mud and unburnt bricks which required hardly any temperature adjustments and therefore very little energy was necessary for heating and cooling. Today's buildings in towns and cities are mostly manufactured from concrete, cement, steel, aluminium, marble, well-burnt bricks and glass. These materials are energy intensive and the houses made out of them need a lot of power to keep them comfortable during the winter and the summertime and also for lighting and decoration. The procedure of manufacture of the materials also consumes enormous amount of energy in several forms.
At earlier times, people used fuel wood or charcoal in kitchens for making food and also in the living rooms for heating. This didn't create any environmental problem such as that of smoke because the houses had separate kitchens at a distance from the main living quarters and the houses were tall having provision of chimneys. This is no more possible in today's housing blocks where the living quarters aren't separated from the kitchens; the RCC structure will not allow having tall roofs and also chimneys. Which means fuel type must be changed as otherwise you will see serious smoke and associated health issues. Kerosene replaced firewood and charcoal as the favourite fuel for the urban homes. Later kerosene gave way to gas and electricity through the 1970s. The dependence on firewood has continued in the rural areas particularly for folks residing in the far-flung areas of the foothills and the forests. Newer tools of comfort came to be found in the urban centers. The use of electric fans through the summer has become a common practice but the effluent has truly gone for air-conditioning in their houses. As the houses have become almost like glass towers and since glass is an extremely bad conductor of heat, this has created problem of large temperature difference between outside and inside of a residence requiring much energy to be spent on air-conditioning. Additional energy need has become necessary for running the lifts and operating a huge amount of other devices of modern life
The other major urban energy need is for transport. The towns and cities are roaming with buses, trucks, cars, two- and three-wheelers which rely upon fossil fuels, namely petrol and diesel. The number of vehicles has increased at a very fast rate during the last few years despite the higher price of fuel. Small, narrow and improperly maintained roads and overcrowding have further aggravated the problem. Traffic congestion has turned into a serious problem in all cities. Slower moving vehicles burn more fuel and thereby the efficiency is further reduced. It has also given rise to problems of carbon monoxide pollution, smog and other environmental problems affecting people's health particularly through various respiratory diseases. Time has come to create a competent public transport system, that may lead to substantial energy preservation, minimize congestion and reduce pollution problems.
6. 3 Water conservation, rainwater harvesting, and watershed management
All living organisms require water, plants put it to use in photosynthesis, humans and other animals drink it, and aquatic plants and animals are in it. Water also plays an important part in many natural and human processes and is also a critical component of many physical and chemical reactions. In addition, it supports many economic activities. The quantity of water in the world has remained constant. In fact, water hasn't changed in amount or nature for an incredible number of years. It just keeps cycling and recycling from atmosphere to earth and again. Freshwater is a treasured resource as it makes up less than 3% of the earth's total water resources. Because freshwater is so limited and plays such a key role in world health, economies, and environmental stability, it must be conserved and found in a sustainable manner.
The efficient use of water implies doing more with less. Efficiencies can be gained in all sectors, including agriculture, municipal, domestic, and industry. Central to a successful water conservation program are a knowledge of
The water resource itself (baseline data and monitoring)
How, when, and why water is used (water audits and metering)
The full cost of providing water of suitable quality and disposing of wastewater
Alternative water-efficient technologies, processes, and practices
Attitudes and values related to water and the environment.
Public education and awareness are essential in implementing water conservation. However, they could have to be supplemented by appropriate legislation and regulations and economical incentives and disincentives, including consumption-based pricing.
Demand for further water has been very common. This demand can be reduced by careful planning. This calls for the following measures:
More-efficient irrigation systems
Drought-resistant cultivars and crop rotations
More-efficient livestock watering systems
Water metering and charging for water
Use of effluent and wastewater for irrigation
Household water conservation.
The water resources have to be carefully managed through the following steps:
Dividing water resources into various divisions for effective supply
Laying a network of supply pipelines
Building reservoirs for storing water
Increasing water availability through groundwater extraction
Treatment of wastewaters and making arrangement because of their reuse
Reducing losses through seepage and evaporation.
Managing Excess Water. Sometimes, more water can be acquired than the actual need. In such cases, the management of the surplus water can be achieved by firmly taking it to deficient areas through drainage:
Many agricultural areas are low lying or found in flood plains and require drainage to be profitable. Good drainage boosts plant growth and crop productivity, really helps to reduce soil salinity and erosion, and allows farmers a wider selection of crops and a longer growing season, which help to decrease the costs of production.
There are two types of artificial drainage system: surface and subsurface. Surface systems may donate to declining water quality in watercourses by releasing drainage water containing sediments, nutrients, and chemicals. Subsurface systems release substances that leach through the soil, such as nitrate, pesticides, and bacteria.
Drainage systems can also alter the surroundings by draining wetlands, removing riparian zones, increasing runoff, and changing a region's hydrology. Proper design and maintenance of drainage systems may alleviate a few of these effects, but lost riparian and wetland systems are usually difficult and expensive to replace.
On-farm drainage systems cannot handle large volumes of stormwater received from developed uplands. Properly designed regional drainage systems may be had a need to protect lowland agricultural areas. However, damage from major floods cannot continually be prevented.
Maintaining Reliable Water Supplies
A sufficient supply of good quality water is necessary for agricultural activities such as irrigation and livestock watering, as well for domestic, municipal, industrial, recreational, and other uses. Water needs to be conserved for the lean periods such as drought. Droughts are extremely common but difficult to predict. They occur frequently in dry regions, but other regions could also have shorter, less serious periods of drought. Drought threatens both crop and livestock production. Along with the potential risk of global warming and increasing trends in population, urbanization, and consumptive use, the impacts of drought may become much more serious.
The development of storage reservoirs is vital for maintaining sufficient year-round supplies, particularly through the dry season. Groundwater is an important source of water and even though the groundwater level falls through the dry season, sufficient water can be extracted for meeting different needs. Sustainable use of groundwater resources is determined by withdrawing water at rates that do not exceed recharge rates. Deep aquifers recharged only by water filtering through overlying materials are particularly at risk of over-withdrawals.
Measures have been taken throughout the world for reuse of wastewater at least for irrigation and other non-drinking uses. An enough way to obtain good-quality water available across the year is vital for those human activities. Concerns continue to mount about the availability of water as demands and competition for water grow in all sectors of society. Management of water supplies must consider all competing uses of water, including those associated with agriculture, industry, municipalities, recreation, and aquatic ecosystems.
Drought
Drought is a prolonged amount of abnormally dry weather that depletes water resources. Because most human activities and ecosystems are dependent on reliable and sufficient water resources, the impacts of drought are far reaching. Drought affects our lives by
Putting stress on water and food supplies
Degrading the surroundings through poorer water quality and much more forest fires, soil erosion, and insect infestations
Affecting the economy by reducing the capacity for agricultural production, power generation, transportation, and manufacturing,
Causing soil moisture deficit in farmland soils and thereby threatening both crop and livestock production resulting in severe financial losses to farmers.
Global warming scenarios predict that unless the warming is controlled, the frequency and severity of drought increase and the occurrence will be unpredictable with respect to time and location.
Three basic types of drought might occur separately or simultaneously:
Meteorological drought occurs when precipitation is significantly below normal over a long period.
Agricultural drought occurs when low soil moisture and scarce water supplies stunt crop growth, reduce crop yields, and endanger livestock.
Hydrological drought occurs when a lengthy meteorological drought causes a sharp drop in the degrees of groundwater, rivers, and lakes.
The timing of an drought may determine its effects. For instance, summer drought usually causes more problems since it coincides with the time of highest water demand. It really is to be noted that drought is the consequence of several factors such as
Below normal precipitation
Extended hot dry air
Already low soil moisture.
Because of this complexity, a sizable selection of climatic and hydrological variables are needed to monitor and find drought, including temperature, precipitation, soil moisture, stream flows, and water supply conditions. The serious impacts of drought demand a built-in effort from the physical, biological, and social sciences to build up effective responses.
Surface water management
Surface water management requires effective measures to control the extremes of floods and droughts, while maintaining a trusted water supply to meet the basic needs of human life and the demands of monetary development. Because of the high amount of variability of precipitation, water storage is a must to provide a year-round supply of water. The storage in the form of reservoirs, dams, dugouts, and natural lakes has been a common practice. A significant challenge to water managers is locating surface water supplies relative to that of water users. Water users (domestic, municipal, agricultural, and industrial) usually need a range of resources and services and are not always located nearby the water sources. Providing a reliable supply of water to users often requires distribution networks comprising canals and pipelines.
Wetlands
Wetlands are areas saturated with water for long enough to significantly alter soil and vegetation and promote aquatic processes. The five main types of wetlands-bogs, fens, swamps, marshes, and shallow water-are characterized by
A seasonal or long lasting covering of shallow water
A water table at or near the surface for the majority of the growing season
Saturated organic and natural soils, or peat, the productivity which will depend on the nutrient status and the pH of the site
Water-loving plants, such as cattails, rushes, reeds, sedges, dogwood, willows, and cedars.
Wetlands give a number of environmental benefits, i. e. they
provide habitat for wildlife,
improve water quality by serving as biological filters and mechanical settling and filtering ponds, which help to eliminate impurities from the,
recharge groundwater,
augment low flow in watercourses,
serve as a buffer against drought,
reduce the risk and damage of flooding by storing large volumes of water during heavy rainfall, rapid thaws, or runoff events, and
stabilize shorelines.
The other important services rendered by wetlands are (a) they offer recreational, educational, and financial opportunities, through canoeing, fishing, hunting, ecotourism, school trips, and the harvesting of resources (e. g. , wild rice), (b) the wetlands support a huge range of waterfowl species that use wetlands for nesting habitat, protective cover, or sources of food, (c) wetlands are equally important to non-avian wildlife as they provide essential breeding habitat for most amphibian and reptile species, (d) also, they are the prime locations, along with waterways, for a huge number of freshwater fish seeking shallow waters for cover, spawning, and nurseries, (e) wetlands serve as primary habitat to mammals adapted to aquatic conditions (e. g. , beavers and musk-rats), and secondary habitat for other upland species that occasionally use these areas to flee predators, reproduce, or forage (e. g. , raccoons, shrews, and moose).
The wetlands thus hold considerable biodiversity because of the unique blend of water and land. The wetlands have high productivity as they are the breeding and feeding grounds for a large number of invertebrate species at the bottom of food chains. Directly or indirectly, the invertebrate communities support species of birds, mammals, amphibians, and reptiles, as well as much other fish and plant species, including endangered or threatened species. The wetlands also contribute significantly to the biological diversity beyond their borders. For instance, deer or moose commonly use a hardwood forest in winter when thick conifers, commonly associated with swamps, are nearby to provide thermal cover.
Encroachment, expansion of human habitats and building of roads and railways over the wetlands, establishing industries have caused substantial lack of wetlands in the last few decades. Wetlands sustain many ecosystems and even if a part of the wetland is destroyed, it may lead to elimination of important ecosystems.
Lakes and ponds
Lakes and ponds provide a diversity of aquatic habitat. The littoral zone of these water bodies is defined as that portion where sunlight can reach underneath, usually in shallow areas close to the shore (up to 5 meters deep, depending on turbidity). This is the most productive part of lakes and ponds, and it supports a variety of waterfowl and shorebirds, fish, amphibians, reptiles, mammals, and plants. Most fish, cold- and warm-water species alike, rely on the littoral zone because of their early life stage requirements (for spawning, larval, and juvenile stages). Nutrient enrichment of lake and pond water can promote eutrophication, as it can in streams and rivers. Pesticides that enter ponds and lakes have the potential to disrupt the metabolism of organisms at all levels of the food chain in the aquatic system.
Floodplains
Floodplains are the low-lying flat lands that border streams and rivers. When a watercourse reaches its capacity and overflows, such as during continuous heavy rains, the excess water is accommodated by the floodplain. The floodplains serve to
receive sediments that settle out of flood waters,
absorb and store water during floods and rainfall which later becomes available to plants, including agricultural crops, during the dry months,
provide large expanses of wildlife habitat that supports diverse plant and animal communities, and
help fish to survive during high flood by providing low velocity refuge areas.
If water drains out rapidly, the floodplain does not have plenty of time to soak up water. This lowers this particular table and correspondingly, the groundwater availability through the dry months decrease. This normally happens in urban and residential areas due to creation of impervious built-up surfaces when the runoff volume increases and causes waterlogging in low lying areas. These reduce the natural flood plain area and contribute to greater flow, erosion, and damage downstream.
Problems created by impervious surfaces
Urban development creates large areas of impervious cover, such as roofs and pavement that cannot absorb rainfall. As forests are removed or low-lying lands are chock-full to increase habitat area, water-retaining capacity of the soil declines, and the surface runoff increases in volume. It becomes quite difficult to manage the increased runoff and the low lands suffer from problems of excessive water accumulation for a long period. Inside the flat and fertile agriculture lowlands of the watershed, the runoff influences agriculture seriously leading to lack of valuable crops, livestock, machinery, and structures. Construction of barns, feedlots, and greenhouses has increased the areas under impervious surface even in the agricultural areas, further reducing the capacity of soils to soak up water.
Limits on Water use
Use of water for different purposes is slowly but surely increasing and the demand is likely to rise several folds in the immediate future. This may even give rise to conflicts among localities, people and nations. While agriculture remains the chief water-user, competition is probable from such sectors like thermal power generation, manufacturing, and municipal water use. Water management has become a prime responsibility of the nations. If water is unavailable, both agriculture and livestock production will be affected. Drought is a severe problem in many countries and its own effective control involves proper water management. It really is predicted that climate change processes will increase both flood and drought, and the countries must plan for the future assuming severe water shortages. Alternative farming practices that aren't solely dependent on water availability have also to be developed.
Thermal power generation
Thermal power generation withdraws much more water than agriculture. Production of 1 kilowatt-hour of electricity requires 140 liters of water for fossil fuel plants and 205 liters for nuclear power plants. Conflict may arise between agriculture and the thermal power sector if thermal plants are situated in agricultural areas.
Manufacturing
The manufacturing industry withdraws more water than agriculture, but consumptive use is higher for agriculture. The trend to expand value-added processing of agricultural products may increase the competition for water between agriculture and manufacturing industries.
Municipal water use
Municipal water use and population are projected to grow together, possibly conflicting with agricultural growth in areas lacking water. Towns and cities may compete for water supplies needed by agriculture, particularly in irrigated areas. Conflicts could also arise if water destined for municipal use is polluted therefore of agricultural activity.
Water use by Fish and wildlife
Pollution of fishery waters therefore of agriculture could give rise to conflict between agriculture and the fisheries sector and potentially limit the growth of agriculture. A demand to get more land for developmental work may exert pressure on wetlands and other habitats of fish and wildlife. This could seriously affect option of water for fish and wild animals.
Water allocation
Whatever water is offered should be distributed and used properly and all governments should initiate actions for allocating water for different sectors. The normal water needs of the people must be met but there should also be enough allocation for agriculture. Serious conflicts have arisen all across the world (also in India) for allocation of water from the rivers through the lean months. Inter-state conflicts on water continue steadily to take up a lot of attention of the Central Government and the judiciary in India.
Effects of agriculture on water
Agricultural practices have undergone tremendous changes over the last 50 years due to the technological advances taking place. Productivity has increased due to use of modern mechanized agriculture and use of fertilizers and pesticides to maintain production levels. These new techniques have also contributed to some degree of environmental degradation, like the decline of water quality. Water pollution is one of the consequences of modern agriculture.
The main pollutants coming from farmland to water are sediments, nutrients (especially nitrogen and phosphorus), pesticides (including insecticides, herbicides, and fungicides), bacteria, and salts. The occurrence of these substances can make water unfit for uses by humans and wildlife. The grade of freshwater resources is the first ever to be affected by agriculture. However, the impact is also felt in some estuarine, coastal, and marine waters that receive runoff from agricultural fields.
The construction of dams and reservoirs, distribution of irrigation water, drainage of wet soils, including wetlands, and sedimentation of streams and lakes are also very likely to alter the water quality. These activities completely change the esthetic appeal of the countryside, affect wildlife habitat and present rise to conflict with other users of water.
Rainwater Harvesting
To meet water demand during the lean seasons, folks have taken to rainwater harvesting when they store the rainwater for use later. Rainwater harvesting (RWH) is a way of collecting, storing and conserving roof top water runoff and local surface water runoff. In industrialized countries, sophisticated RWH systems have been developed with the purpose of reducing water bills or to meet up with the needs of remote communities or individual households in arid regions.
In countries like Uganda and Sri Lanka, rainwater is collected from trees, using banana leaves or stems as non permanent gutters; up to 200 liters may be collected from a big tree in a single storm. A lot of people and groups have taken the initiative and developed a wide variety of RWH systems across the world.
RWH has come to mean the control or usage of rainwater near to the main point where rain reaches the earth. Used, the RWH may be divided into two categories
RWH for domestic use, and
RWH for agriculture, erosion control, flood control and aquifer replenishment.
RWH is a possible source for meeting water demand in a few areas, but is often overlooked by planners, engineers and builders. In many areas, where RWH has been introduced as part of a wider drinking water supply programme, it was initially unpopular, due to the fact little was known about the technology by the beneficiaries. In most of these cases, the technology has quickly gained popularity as an individual realizes the advantages of a clean, reliable water source at the home, when the supply is unreliable or inadequate, or where local water sources dry up for an integral part of the year. Oftentimes, RWH has been introduced as part of a built-in water supply system. It is a technology that is flexible and adaptable to an extremely wide variety of conditions, being found in the richest and the poorest societies in the planet, and in the wettest and the driest regions of the globe.
Rain water harvesting is vital because
Surface water is inadequate to meet our demand and we must depend on groundwater,
Due to rapid urbanization, infiltration of rainwater into the sub-soil has decreased drastically and recharging of groundwater has diminished,
Over exploitation of groundwater resources has led to decline in water levels in most area of the country,
To enhance option of groundwater at specific place and time,
To arrest sea water ingress,
To improve the water quality in aquifers,
To improve the vegetation cover,
To raise the water levels in well and bore-well,
To reduce power consumption.
Rainwater harvesting is determined by end use application such as
Roof top rainwater captured from the roofs of buildings on residential property can be utilized for various needs such as domestic use, irrigation of flower gardens, car washing, etc.
Rainwater harvesting can be utilized for inducing, collecting, storing and conserving local surface runoff for using in irrigation, reducing soil moisture deficit and then for ground water recharge.
Rainwater conservation has four phases. The four phases are:
Rainfall induces surface flow on the runoff area.
At the low end of the slope, runoff collects in the basin area.
The major part of water collected infiltrates and it is stored in the root zone of the soil.
After infiltration has ceased, the conservation of the stored soil water follows.
In Orissa, for example, the common annual rainfall is around 1500 mm, which is quite saturated in comparison to world's average rainfall (i. e. 800 mm. ). But this rainfall occurs for a very short period. Because of this, maximum amount of rainwater flows away very rapidly with poor recharge of ground water. So, scarcity of water for domestic purpose is a common phenomenon in most parts of Orissa. This issue can be reduced if the surplus rainwater is harvested and stored for use during the lean period.
