Natural resources
Natural resources are the resources available in a nature like air, water, sunlight, soil, minerals, forests, wild life etc.Natural resources are of two main types. They are renewable and non-renewable natural resources.
i) Renewable natural resources
Those resources which can be replenished in a short period of time like air, water, sunlight, forests etc.
ii) Non-renewable natural resources :-
Those resources which cannot be replenished in a short period of time like minerals (coal, petroleum, natural gas, metals etc.) because they take millions of years to be formed. Human activities produce a lot of waste materials which are thrown away into the environment. These wastes cause pollution of natural resources like air, water and soil
The Three R’s to save the environment :-
The three R’s to save the environment are Reduce, Recycle and Reuse.
i) Reduce :- means using less of natural resources and avoiding wastage of natural resources.
ii) Recycle :- means the materials like paper, plastic, glass, metalse tc used for making things can again be used for making new thingsi nstead of synthesising or extracting new paper, plastic, glass orm etals.
iii) Reuse :- means using things again and again like the plastic bottles in which we buy jams, pickles etc can be again used for storing things in the kitchen.
Need for management of natural resources :-
All the things we use and consume are obtained fromn atural resources. Due to increase in population, industrialisation and urbanisation the demand for natural resources is increasing and their availability is limited . So there is a need for proper management of natural resources.
The proper management of natural resources consists of :-
i) Judicious use of natural resources and avoiding wastage of natural resources.
ii) Long term planning for the use of natural resources so that it last not only for the present but also for future generations.
iii) The exploitation of natural resources should not be for the benefit of a few people but should be distributed equally for all.
iv) While extracting and using natural resources we should also plan for the safe disposal of wastes so that no damage is caused to the environment.
Water :-
a) Uses of water :-
Water is a basic necessity for all living things. We use water for our daily needs, for agriculture, transportation, construction of buildings, roads, dams etc. Water is a natural habitat for aquatic organisms.
Human activities are affecting the availability of water and causing pollution of water bodies.
b) Dams :-
Advantages of dams :-
i) Irrigation of crops.
ii) Producing electricity.
iii) Supplying water to towns and cities.
iv) To control floods.
Disadvantages of dams :-
i) Social problems :- It displaces a large number of people who have to be rehabilitated.
ii) Economic problems :- It is expensive and uses a huge amount of public money.
iii) Environmental problems :- It causes deforestation and loss of biodiversity.
Water harvesting (Rain water harvesting) :-
Water harvesting is collecting and storing rain water for future use.
The common methods of water harvesting are :-
i) Digging pits, ponds, lakes etc.
ii) Building small earthen dams or concrete check dams.
iii) Construction of dykes.
iv) Construction of reservoirs.
v) Construction of rooftop collecting units in houses.
Advantages of underground water :-
i) It does not evaporate easily.
ii) It spreads out and recharges wells.
iii) It provides moisture for irrigation of crops.
iv) It does not get polluted easily.
v) It does not provide breeding ground for mosquitoes and houseflies.
Coal and petroleum :-
Coal and petroleum are fossil fuels formed by the decomposition of dead plants and animals inside the earth after several millions of years. They are non-renewable sources of energy. Petroleum reserves may last for about 40 years and coal reserves may last for about 200 years. Coal and petroleum contain carbon, hydrogen, nitrogen and sulphur. When they are burnt, they release carbon dioxide and oxides of nitrogen and sulphur. Carbon dioxide is a green house gas which causes global warming. Oxides of nitrogen and sulphur combines with moisture in the air and produces acid rain
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