WATER
About three-fourths of the earth’s surface is covered with water. But most of the water on earth is in the oceans. Ocean water is saline and hence is not fit for human consumption. Just 2.7% of the total water on the earth is available as freshwater. But 70% of the total freshwater on the earth is available as frozen ice in glaciers and icebergs. This leaves less than 1% of the total water on earth for human consumption. This is available as groundwater, as surface water and as water vapour.
Hence, freshwater is a precious resource for us. The total volume of water on the earth remains constant. Water keeps on getting cycled through oceans, the air, the land and back to ocean; through a process called water cycle.
Human beings use water for a variety of purposes; like drinking, bathing and washing. Water is also used in production of various things for our use. Moreover, water is used in agriculture, industries and in electricity generation.
Increasing population has resulted in exploitation of water on an even larger scale. This has resulted in shortage of water at many places. Shortage of drinking water is a major problem in many parts of the world. Almost all the continents are facing the problem of water scarcity.
Conservation Of Water Resources
- Access to clean and adequate water is a major problem in the world. Overuse and pollution of water have made it unfit for use at many places. Sewage, agricultural chemicals and industrial effluents are often discharged into water bodies either in partially treated or untreated form. They pollute the water with various kinds of contaminants. Treatment of these effluents can help in controlling water pollution.
- Forest and vegetation cover slow the surface runoff and thus help in recharging the groundwater. Surface runoff can also be reduced by applying the methods of water harvesting.
- Canals should be properly lined to minimize the losses by seepage. Sprinklers and drip irrigation help in minimizing the use of water for irrigation and thus help in conservation of water.
NATURAL VEGETATION AND WILDLIFE
Biosphere: Natural vegetation exists only in the biosphere. The narrow zone of contact between the lithosphere, hydrosphere and atmosphere; in which life exists is called biosphere.
Ecosystem: The living beings are inter-related and interdependent on each other for survival. This life supporting system is called ecosystem.
Importance of Natural Vegetation: Vegetation provides shelter to animals and provides us with timber and many other forest produce. Plants also produce oxygen when they make food and oxygen is the gas we breathe. Plants protect soil from degradation. Plants help in recharging the groundwater.
Wildlife: Animals, birds, insects as well as the aquatic life forms comprise the wildlife. We get meat and leather from animals. Honey bees provide us with honey. Insects are the major pollinators and thus help not only the plants but also the human beings. Some animals play the role of scavengers and clean the dead remains of animals. All animals play important role in maintaining the balance in the ecosystem.
DISTRIBUTION OF NATURAL VEGETATION
- Temperature and moisture determine the growth of vegetation in a particular region. Forests, grasslands, scrubs and tundra are the major vegetation types in the world.
- Huge trees can thrive in areas of heavy rainfall. Thus, dense forests are present in areas which have abundant supply of water. The size and density of trees decreases with relative decrease in moisture.
- Short stunted trees and grasses grow in the regions of moderate rainfall. Thorny shrubs and scrubs grow in dry areas which get low or negligible rainfall. The Tundra vegetation is found in cold Polar Regions and comprises of mosses and lichens.
Evergreen Forests: Trees of evergreen forests do not shed their leaves at a particular time in a year. Evergreen forests are found in tropical regions which get plenty of sunshine and rainfall.
Deciduous Forests: Trees of deciduous forests shed their leaves at a particular time in a year. Deciduous forests are found in subtropical regions which get moderate sunshine and rainfall.
CONSERVATION OF NATURAL VEGETATION AND WILDLIFE
Deforestation, soil erosion, construction activities, forest fires, tsunami and landslides are some of the factors which are causing extinction of forest and wildlife resources. Poaching is another concern which is leading to extinction of valuable wildlife.
- The government has made national parks, wildlife sanctuaries, and biosphere reserves to protect the natural vegetation and wildlife.
- Many awareness programmes; like social forestry and Vanamahotsava are also encouraged to conserve the wildlife and forests.
- Many laws have been passed to make poaching an illegal and punishable offence. In India, killing of lions, tigers, deer, etc. have been banned.
- An international convention CITES has been established that lists several species of animals and birds in which trade is prohibited. CITES stands for Convention on International Trade in Endangered Species of Wild Fauna and Flora. About 5,000 animal species and 28,000 plant species are being protected under the CITES.
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