2. What is the difference between saline water and freshwater? What are the sources
of each on the earth?
3. What do you understand by the following? a) Wells b) Tubewells c) Handpumps
4. Why are dams referred to as 'multi-purpose projects'?
5. What is a canal? How is it beneficial?
Answers
Explanation:
2.Salt water is water that contains a certain amount of salts. This means that its conductivity is higher and its taste much saltier when one drinks it. Salt water is not suited to be used as drinking water, because salt drains water from human bodies. When humans drink salt water they risk dehydration. If we want to drink seawater, it needs to be desalinated first. Salt water can be found everywhere on the surface of the earth, in the oceans, in rivers and in saltwater ponds. About 71% of the earth is covered with salt water.
Freshwater is water with a dissolved salt concentration of less than 1%. There are two kinds of freshwater reservoirs: standing bodies of freshwater, such as lakes, ponds and inland wetlands and floating bodies of freshwater, such as streams and rivers. These bodies of water cover only a small part of the earth's surface, and their locations are unrelated to climate. Only about 1% of the earth's surface is covered with freshwater, whereas 41% of all known fish species live in this water. Fresh water zones are usually closely connected to land; therefore they are often threatened by a constant input of organic matter, inorganic nutrients and pollutants.
3. c Hand pumps are manually operated pumps; they use human power and mechanical advantage to move fluids or air from one place to another. They are widely used in every country in the world for a variety of industrial, marine, irrigation and leisure activities. There are many different types of hand pump available, mainly operating on a piston, diaphragm or rotary vane principle with a check valve on the entry and exit ports to the chamber operating in opposing directions. Most hand pumps are either piston pumps or plunger pumps, and are positive displacement
a. A well is an excavation or structure created in the ground by digging, driving, or drilling to access liquid resources, usually water. The oldest and most common kind of well is a water well, to access groundwater in underground aquifers.
4. Dams are called multi-purpose projects because:1 Earlier they were built to impound rivers and rainwater could be used later for irrigation.2 Now dams are built not only for irrigation but for generation of electricity water supply for domestic use flood control recreation inland navigation and fish-breeding.3 Thus they are called multi-purpose projects.4 For example in the Sutlej-Beas river basin the Bhakra-Nangal project water is being used both for hydelpower production and irrigation.
5.Canals are fed by rain water received by rivers, and the water is used for irrigation. Production of crops needing more water is also possible through canals. As compared to un-irrigated soils, higher productivity per hectare is also possible due to canals. The main advantage to canals is the ease of shipping good.
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Answer:
2.saline water are salty( ocean,sea) ,while freshwater are not salty(river, streams)
3.A .well is an excavation or structure created in the ground by digging, driving, or drilling to access liquid resources, usually water.
b. tube well is a type of water well in which a long, 100–200 millimetres (3.9–7.9 in)-wide, stainless steel tube or pipe is bored into an underground aquifer. The lower end is fitted with a strainer, and a pump lifts water for
c. Hand pumps are manually operated pumps; they use human power and mechanical advantage to move fluids or air from one place to another. They are widely used in every country in the world for a variety of industrial, marine, irrigation and leisure activities.
4. they are known as multi purpose project because they ar constructed for various purpose ( electricity, providing water for irrigation . etc)
5.Canals are fed by rain water received by rivers, and the water is used for irrigation. Production of crops needing more water is also possible through canals. As compared to un-irrigated soils, higher productivity per hectare is also possible due to canals. The main advantage to canals is the ease of shipping goods.