3 TYPES OF NATURAL RESOURCES1) Land – provides us with most of the requirements like food, houses, clothing etc.- 30% of the land available is use to man.- Many parts are mountainous, rocky or deserts which are not of much use for the purpose of building or cultivation.Noted:As the requirement for land for urbanization increases, more and more forests are being cut down to make more land available. Due to rapid deforestation, the natural cycle of generation of forests is being disturbed due to which the area of forests is decreasing considerably. This in turn is affecting the plant and animal kingdom.Forests Play a Vital Role:- They purify the air and control pollution to some extent.- Regulate the climatic conditions.- Replenish the ground water.- Decrease the run-off rate of rainwater.- Control floods.- Prevent soil erosion.- Maintain the fertility of the soil.- Support a wide variety of plant and animals species and provide a natural habitat to them.2) Water – is one of the unique features of the earth which makes life possible in its present form.- 70-75% of the surface of the earth covered with water.- 90% of water is present as oceans and seas.- Exists in 3 forms ( solid, liquid, gas )Sea Water – sodium chloride or common salt forms 80% of the dissolved salts found in sea water. Products extracted from sea water are cooking salt, magnesium and bromine.Fresh Water – suitable for human consumption are found in lakes, rivers rain, ground water etc. In the form of rain or snow, is formed from the condensation of the water vapour present in air. Rain water accumulates in lakes and rivers and seeps into the soil as ground water.NOTED:The water on the earth’s surface and in its atmosphere is always in motion. The sun evaporates it from the ocean’s surface, the wind blows over the resulting vapour over the land, where it falls as rain, collects in rivers and flows back to the sea called water cycle.HUMAN USES THE WATER RESOURCES:- Human use water for drinking, washing, cooking, agriculture etc.- Industries set up by man use water extensively for purposes.- The gaseous form of water (steam) is used as a source of energy.- Waterfalls, dams and tides are used to generate electricity.- Oceans are the productive environments for marine vegetation and marine animals.- Oceans are source of various minerals and salt. (Salt used in our food)- Fishes and other marine life are source of food and livelihood.- Oceans, seas and rivers provide us with a ready-made transport pathway on which ships and boats.- Shells, pearls and other semi-precious stones from the sea beds are used in making jewellery and other aesthetic objects.- Water plays an important role in the wear and tear of rocks resulting in the formation of soil.3) Air – is a renewable and inexhaustible natural resource. -It is indispensable for all life forms (humans, plants and animals). - is a mixture of gases.Atmosphere - envelope of air that surrounds us. Can be divided into many other layers or zones. USES OF THE ATMOSPHERE:- Use in respiration- Ozone layer of the atmosphere protects us from the harmful ultraviolet rays coming from the sun. (UV radiation is responsible for giving people sun burn and can cause skin cancer.) - Heat – type of energy absorbed or reflected by the gases in the atmosphere.- The air currents help to maintain suitable climatic conditions and facilitate the formation of rain.- Wind is the fast moving air. Used as a source of energy, to pollinate plants, to disperse seeds, to transport rain bearing clouds from one place to another.- Aviation transport reduces the pressure on land transport.- Air plays a vital role in communication. Sound, like radio and television signals, need air to be transmitted. - Ionosphere reflects back radio waves to the surface of the earth making this type for communication.Noted:Heat from the sun is reflected by the atmosphere so that the earth does not get too hot. At night, the atmosphere prevents the earth heat from escaping into space. The surface does not het too cold at