Class 10 Science


Water, Coal and Petroleum

These notes are based on the chapter management of natural resources from class 10 science NCERT book and CBSE syllabus.

  • Exploitation of water
  • Waterhsed Management
  • Coal and Petroleum and harms caused by them

Water, coal and petroleum are important natural resources. We cannot survive without water but exploitation of water is causing scarcity of water everywhere. Coal and petroleum are fossil fuels which are very important for the economy. But there are many harms of using coal and petroleum. There is a need for judicious use of these natural resources.

Water is necessary for sustaining life. While availability of water is not an issue for aquatic living beings, it is crucial for terrestrial forms of life. Water is available in plenty on the earth. But distribution of water is not even throughout the earth. In case of India, varying rainfall pattern means some regions of the country get plenty of rain while some others may face drought like situation.

Exploitation of Water

Various human activities have also resulted in scarcity of water at many places. Loss of forest cover, exploitation of groundwater and diversion of water for high water demanding crops are some of the reasons for scarcity of water.

Water Harvesting

India has had a long tradition of making water harvesting structures which were based on the principles of sustainable development. But the British rule and subsequently, policies of various governments in independent India saw a thrust on making large dams and canals for utilization of water resource. The changed policy overlooked the utility of traditional water harvesting structures.

Dams

Large dams are built primarily for generating electricity. After that, water from these dams is released into canals so that water can be utilized for irrigation and other needs. Benefits of these projects have reached a handful people and have left majority of people high and dry.

Problems with Dams

Construction of large dam creates many problems. Construction of large dam needs lot of public money. These dams inundate a large swath of land which falls under the catchment area of dam. This results in large-scale displacement of people and destruction of flora and fauna. Decomposition of vegetation in submerged are releases a huge amount of methane gas which is a greenhouse gas. Due to these reasons, there is a growing criticism against construction of large dams.

Watershed Management

Watershed management stresses on scientific soil and water conservation in order to increase biomass production. This sentence may sound somewhat complicated to you. Let us try to understand it in bits and pieces. Soil and water are necessary for growing plants. When plants make food through photosynthesis, we say that they are increasing biomass. When animals eat plants or animals, they increase their own biomass. So, we can say that availability of quality soil and water helps in increasing biomass.

Watershed management also helps in preventing droughts and floods. At present, many organizations are working on rejuvenating ancient systems of water harvesting so that we can reduce our dependence on mega dam projects. You may have read many news stories about revival of a lost pond or a river due to these efforts.

Most of the traditional water harvesting structures may not be able to retain water for the whole year. But they help in recharging the groundwater. Groundwater is better than water in open reservoir. It does not evaporate and does not get contaminated the way water in open reservoir gets. Moreover, it does not become a breeding ground for mosquitoes.

Coal and Petroleum

Harms of Fossil Fuel

You have read that coal and petroleum are called fossil fuels because they were made from remains of plants and animals. The stock of coal and petroleum is limited and is going to get finished in the near future.

Moreover, burning of fossil fuels causes environmental pollution. It causes an increase in level of carbon dioxide in atmosphere. As carbon dioxide is a greenhouse gas, so it causes global warming. A general increase in average temperature of the earth is called global warming. Global warming is responsible for some dramatic changes in weather patterns which we are witnessing right now. Summers are getting warmer and winters are getting colder. There are increased instances of flash floods and storms which cause huge amount of destruction.

Burning of fossil fuels also releases oxides of sulphur and nitrogen. These oxide cause acid rain when they mix with rainwater.

So, it is necessary to reduce our dependence on coal and petroleum and to search for alternative and cleaner fuels. We can take following steps to reduce our usage of fossil fuels.

  • Use public transport or bicycle for commuting
  • Use LED instead of incandescent bulbs.
  • Use stairs instead of elevator.

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