Renewable Resourse: Water

How water is an renewable resource?

Water is technically considered a renewable resource because it can be used repeatedly and it has a rain cycle. Uses of water include agricultural, industrial, household, recreational and environmental activities. The majority of human uses require fresh water. People use water for their daily needs such as drinking water, washing (cloth), watering animals and irrigating fields.

Studies indicate that a person needs a minimum of 20 to 0 liters of water per day for drinking and sanitation. The world depends on a limited quantity of fresh water. There are increasing concerns about water scarcity in many parts of the world, particularly in developing nations or regions of high population density. Water covers 70% of the earth’s surface but only 3% of this are fresh water. Of this, 2% is in polar ice caps and only 1% is usable water in rivers, lakes and subsoil aquifers. Water can be used repeatedly and it has a rain cycle.

 Water evaporates and returns to earth as rain or snow, runs down the mountain when it melts, flows into oceans. These are all a continuous process. Humans, animals, and plants use water. As water continuously evaporates from the Earth's surface, it collects in the atmosphere to later come back to the Earth as rain. On the Earth itself surface water replenishes groundwater, and groundwater replaces surface water. With careful management and responsible usage, water is a renewable resource.

One of the greatest challenges facing the world in this century is the need to rethink the overall management of water resources. At the global level, 31 countries are already short of water and by 2025 there will be 48 countries facing serious water shortage. This will lead to multiple conflicts between countries over the sharing of water. Around 20 major cities in India face chronic or interrupted water shortages. Local conflicts are already spreading to states. Ex, Karnataka and Tamil Nadu over the waters of the Krishna.  

Over utilization and pollution of surface and underground water

With the growth of human population, there is an increasing need for larger amounts of water to fulfill a variety of basic needs. Today, in many areas, this requirement cannot be met. The over-utilization of water occurs at various levels .Most people use more water than they really need. Most of us waste water during a bath by using a shower or while washing clothes. May agriculturists use more water than necessary to grow crops .There are many ways in which farmers can use less water without reducing yields such as the use of drip irrigation systems. Agriculture also pollutes surface water and underground water stores by the excessive use of chemical fertilizers, and non-toxic pesticides, like Neem products and using integrated pest management systems, all help to reduce the agricultural pollution of surface and ground water.

• Population- Food and water are the basic necessity of human life. Human population appear to have animate drive to use maximum water. Therefore, growing population is the major factor responsible for the over -utilization of water. For example- human population use the water for domestic, agriculture, industrial and infrastructure purpose.
• Urbanization- populations in urban areas have resulted in shortage of water due to high demand. There are many states India, which have over utilized its water resources like Punjab, Haryana and Maharashtra. Therefore, water tables in these states have lowered.
• Commercialization's of agriculture- farmers are producing commercial crops after the success of green revolution. It is estimated that agriculture sector currently uses three-quarters of the world's fresh water. Its -off has degraded the earth's major water resources. This is high demand by agriculture sector for water will continue.
• Industrial sector- Industrial sector makes extensive use of water primarily for cooling soft drinks and power generation purposes etc. However, the inefficient use of water by industries is a matter of concern.

Water that is available in the deeper layers of the earth is known as Groundwater. This water has been trapped inside the earth’s crust for several centuries. The water that is lying under the ground has the capacity to move in general direction of its slope with a very small speed. The bodies that contain such water are known as Aquifers. Water from these aquifers can be drawn by digging wells and pumping water from these wells. Some of these wells can supply very large quantities of water. In some cases, the drinking water needs of cities are completely met by the groundwater bodies. In the agriculture sector also, groundwater is supporting the growth of crops enormously in certain agricultural dominated areas.

Impacts:

1. Loss of integrity of freshwater ecosystems: Human activities for infrastructure development like creation of dams, land conversion, etc. are responsible for this loss of integrity of freshwater ecosystems. Water quality and quantity, fisheries, habitats, etc. are at risk due to this loss of integrity.
2. Risk to ecosystem functions: Population and consumption growth increases water abstraction and acquisition of cultivated land. Virtually all ecosystem functions including habitat, production and regulation functions are at risk.
3. Consumption of living resources and biodiversity: Overharvesting and exploitation causes groundwater depletion, collapse of fisheries. Production of food, quality and quantity of water and supply of water gets badly affected by these depletions of living resources and biodiversity.
4. Pollution of water bodies: Release of pollutants to land, air or water alters chemistry and ecology of water bodies. Greenhouse gas emissions produce significant changes in runoff and rainfall patterns. Because of water pollution, water supply, habitat, water quality, food production, climate change, etc. are at risk.

Effects of Global climate Change on water management

Climate change will affect water resources through its impact on the quantity, variability, timing, form, and intensity of rain.

• Global Climate change: Changes in climate at a global level caused by increasing air pollution have now begun to affect our climate. In some regions global warming and the El Nino winds have created unprecedented storms. In other areas, they lead to long droughts. This has seriously affected regional hydrological condition.
• Water pollution - (Nepal): The Narayani river of Nepal has been polluted by factories located on its bank. This has endangered fish, dolphins, crocodiles and other flora and fauna of the region.
• Floods: floods have been a serious environmental hazard. Deforestation in the Himalayas also causes floods, and because of it, year after year many people kills, damage crops and destroy homes, which are on the bank of Ganges. River change their course during floods and tons of valuable soil is lost to the sea. Wetlands in flood plains are nature’s flood control systems into which overfilled rivers could spill and act like a temporary sponge holding the water, and preventing fast flowing water from damaging surrounding land.
• Drought: In most arid regions of the world, the rains are unpredictable. This leads to periods when there is a serious scarcity of water to drink, use in farms, or provide for urban and industrial use. It is an unpredictable climatic condition and occurs due to the failure of one or more monsoon. While it is not feasible to prevent the failure of the monsoon, good environmental management can reduce its ill effects. The scarcity of water during drought years affects homes, agriculture and industry. It also leads to food shortages and malnutrition, which especially affects children.

Water for agriculture and power generation

India’s increasing demand for water for intensive irrigated agriculture, for generating electricity, and for consumption in urban and industrial centers, has been met by crating large dams. Although dams provide a year supply of water for domestic use, provide extra water for agriculture/industry, helping in creating electricity but it has several serious environmental problems. Because they alter river flows and destroy the lives of local people and the habitats of wild plants and animal species.

Water is a limited and valuable natural resource - it is essential for sustaining agriculture, municipalities, industrial operations, and many forms of electricity generation. As water scarcity increases, recognizing the long-term value of water will be increasingly important. Worsening drought conditions, an increasing population, and higher industrial demand across the United States all contribute to rising competition for water. Among the biggest consumers of water is the energy sector, mainly thermal electric power plants producing power from coal, gas and nuclear. According to a report by the Union of Concerned Scientists, on an average day in 2008, water-cooled thermal electric  power plants consumed from 2.8 to 5.9 billion gallons of the 60-170 billion gallons of freshwater they withdrew. That means that US power plants took in more than triple the amount of water flowing over Niagara Falls.

 While power plants and agriculture currently take in about the same, amount of freshwater. If the energy sector follows the business as usual scenario of relying on fossil fuels, farmers who grow our food will face increasing challenges in watering their crops, as power plants burning fuels coal and natural gas require larger quantities of water.

Water has unique characteristics that determine both its allocation and use as a resource by agriculture. Agricultural use of water for irrigation is itself contingent on land resources. In a situation of growing water scarcity and rising demands for non-agricultural (household and industrial) use of water, reassessment of sectoral allocations of water are inevitable. In developing countries, irrigated agriculture plays a vital role in contributing towards domestic food security. Water provides goods (e.g. drinking water, irrigation water) and services (e.g. hydroelectricity generation, recreation and amenity) that are utilized by agriculture, industry and households.

Sustainable water management

              ‘Save water’ campaigns are essential to make people everywhere aware of the dangers of water scarcity. A number of measures need to be taken for the better management of the world’s water resources. These include measures such as:

• Treating and recycling municipal wastewater for agricultural use.
• Preventing leakages from dams and canals
• Preventing loss in Municipal pipes
• Effective rain water harvesting in urban environments
• Water conservation measures in agriculture such as using drip irrigation
• Pricing water at its real value makes people use it more responsibly and efficiently and reduces water wasting.
• Soil management through afforestation permits recharging of underground aquifers, thus reducing the need for large dams.

Dams have many advantages but it has also several problems:

• Large dams have had serious impacts on the lives, livelihoods, cultures and spiritual existence of indigenous and tribal peoples.
• They have suffered disproportionately from the negative impacts of dams and often been excluded from sharing the benefits.
• Fragmentation and physical transformation of river through dams.
• Dislodging animal populations, damaging their habitat and cutting off their migration routes.