Water Resources New Sparkle Semester Series Social Studies Grade 4 Jeevandeep

water an important natural resource all living things are dependent on water it is an integral part of their bodies many plants and animals can live only in water water is also very important component of our diet we need water for our daily activities like cooking cleaning washing utensils and clothes etc about three-fourth part of our earth also called the blue planet is covered with water this water is present as fresh water sea water and brackish water out of this only 3 percent is fresh water while the rest is sea water and brackish water this is why we must always use water carefully and not waste it fresh water contains lesser amount of dissolved salts than sea water we use fresh water for drinking bathing cooking washing and agriculture rain is the chief source of fresh water on earth fresh water is present in rivers lakes ponds tanks and wells sea water that is present in seas and oceans contains higher amount of salts it is unfit for drinking cooking washing and agriculture brackish water contains more dissolved salts as compared to fresh water but lesser salts than sea water brackish water mostly occurs in places where rivers meet the seas some lakes close to coastal regions are also known to have brackish water this water is not fit for any use our country mostly depends on the monsoon rainfall for agriculture and other purposes agriculture needs regular water supply however since rainfall is not uniform and consistent this creates lot of problems for our farmers who need water to irrigate their fields for this reason development of irrigation systems is necessary irrigation the main source of water on earth is rain when it rains in the monsoons the water resources like ponds rivers lakes etc fill up with rain water the water thus collected is directed to the fields through channels stuck in the ground called canals and is used to water plants and crops this is called irrigation this reduces our dependence on rain some amount of rain water also seeps deep into the ground and get stored there this is called ground water wells are tucked beside the feed to use the underground water for irrigation tube pills are built to draw out water with the help of electric pumps in certain places water is stored in specially built stats meant to provide water for irrigation tabs sometimes strong and high walls are built across river to stop the water from flowing these walls hold back the flow of water they have special gates called the sluice gates to control the flow water is stored in reservoir or artificial lakes that formed behind the dams the water stored here is then channelized for irrigating feeds dams ensure an adequate supply of water by storing it in time soft surplus and releasing it in times of scarcity thus also preventing floods dams are also used to generate hydroelectricity that is electricity generated from water for this reason they are also called multi-purpose projects some important dams or multi-purpose projects in india are bhakra nangal project on satlaj river it is one of the biggest dams in the world tamudar valley project on damoda river biggest dam in india hirakud project on mahanadi river it is the longest man-made dam in india nagarjuna sagar project on krishna river kosi project on kosi river tungabhatra project on tungabhatra river conservation or water water is very precious liquid and must therefore be used carefully when factories dump toxic wastes into rivers the water gets polluted or dirty polluted or dirty water is unfit for use and often dangerous to conserve water means to use it carefully so as to avoid wastage we can reuse water for different purposes thus avoiding its wastage this is called recycling of water thus we now know about the water resources of india