Page 1 :
A+ SOCIAL SCIENCE STD - VIII, UNIT: 12, , WATER ON EARTH, 1. On which day we celebrate World Water Day?, , , March 22nd, , , , Earth, , , , Three-fourth of the earth's surface is covered with water. 71 percent of the earth's surface is, , 2. Which is the only living planet in the solar system?, 3. Earth is also known as the watery planet. Why?, covered with water., , 4. List out any five sources of water., , , Oceans, , , , Wells, , , , , , Springs, Ponds, , Rivers, , 5. Which type of water can be seen more on earth- fresh water or saline water?, , , Saline water, , , , 97%, , , , 3%, , , , The cycle of processes by which water circulates between the earth's oceans, land and, , 6. What is the percentage of saline water to the total water on earth?, 7. How much percentage of fresh water is available for humans?, 8. Define Water cycle., , atmosphere involving precipitation as rain and snow, drainage in streams and rivers, and, return to the atmosphere by evaporation and transpiration, , 9. How can we classify sources of water? Give examples., , , Surface water and Ground water., , , , Ground water: Wells, ponds, tube wells, , , , Surface water: Oceans, rivers, lakes and backwaters, , 10. What is porosity? Write an example for porous material., , , , Porosity is the term for the porous state., Eg: Clay, , 11. What do you mean by permeability?, , , Water will be available only at places where the pores in the rocks are inter-connected., , A+ BLOG- www.apluseducare.blogspot.com Whatsapp 9746544422, , Page 1

Page 2 :
A+ SOCIAL SCIENCE STD - VIII, , , This is due to the fact that water can move through these pores. This quality of rocks is, known as permeability., , 12. What is the reason for accumulation of water in paddy fields?, , , In paddy fields we can see the presence of clay. It has high porosity but low permeability., This means that clay will not permit water to pass through it., , 13. What do you mean by ' water table'?, , , The surface of the water-rich part beneath the ground is known as' water table'., , , , The water stored beneath the ground is the 'underground water'., , , , Water that percolates through the top soil will be collected in the pore spaces of the soil and, , 14. Define the term 'underground water'., 15. What are aquifers?, , gaps in the rocks. Such storage spaces are called aquifers., , 16. The water table rises during rainy season and lowers during summer. Why is it so?, , , Water table rises during rainy season due to recharge received from rainfall and falls back, during summer season due to lack of recharge, , 17. In which situations tube wells are ideal?, , , It is difficult to dig wells where the water table is deep. Tube wells are ideal in such, situations., , 18. In sandy regions which type of wells are used?, , , Filter point wells - shallow tube wells dug in sandy regions., , , , If there be a permeable rock layer in between two impermeable rock layers. Water will rise to, , 19. What are artesian wells?, , the surface automatically due to pressure if we dig to this permeable rock layer. Such wells, are known as artesian wells., , 20. Explain spring and hot spring., , , Water will be flowing out along the surface wherever water table touches the ground. This is, , , , At some places such water flows are characterised with hot water. These are known as hot, , known as "spring"., springs., , 21. What is geysers? Write an example., , , The phenomenon of severe ejection of water from within the earth at regular intervals is, , , , Example - The Old Faithful geyser of the Yellow Stone National Park in U.S.A., , known as "geysers"., , 22. Write the reason for the formation of hot springs and geysers., A+ BLOG- www.apluseducare.blogspot.com Whatsapp 9746544422, , Page 2

Page 3 :
A+ SOCIAL SCIENCE STD - VIII, , , The water that seeps through the fissures on the earth comes in contact with the magma and, leads to the formation of hot springs and geysers, , 23. Write short note on Wetlands, , , Wetlands are natural sinks of surface water. Paddy fields, ponds, swampy region and all low, , , , The water stored here form part of the ground water., , lying regions come under the category of low lands., , 24. Reclamation of the wet lands lead to several environmental problems. Write any two, , , , Lowering of water level in wells., , Floods become common in rivers even in slight rains., , 25. On which day we celebrate World Watershed Day?, , , February 2nd, , , , For drinking., , , , For cleaning dishes., , , , For cooking., , , , for watering plants., , , , for washing clothes., , , , for bathing., , , , for generation of hydroelectricity., , 26. List out the uses of water., , 27. Point out the threats to water resources., , , Even the available fresh water sources are on the verge of depletion, , , , Increase in the consumption of water has also influenced the availability of water., , , , Water pollution, , 28. Identify any five situations that lead to water pollution., , , The waste from households, factories, or agricultural land gets discharged into rivers or lakes, , , , Dumping, , , , Oil pollution, , , , Acid rain, , , , Industrial waste, , A+ BLOG- www.apluseducare.blogspot.com Whatsapp 9746544422, , Page 3

Page 4 :
A+ SOCIAL SCIENCE STD - VIII, 29. What is water pollution?, , , The undesirable change in the physical, chemical and biological properties of water is termed, as water pollution., , 30. Name the law that enforces the control of water pollution in our country., , , The law on prevention and control of water pollution., , , , Water pollution not only affects the availability of fresh water, but leads to the pollution of, , , , The survival of plants and animals are put to danger., , 31. What are the effects of water pollution?, land and air as well., , 32. What can be done by individuals and society to check water pollution?, , , Reduce the use of herbicides, pesticides, and fertilizers., , , , Always opt for recyclable and reusable options, , , , , , Proper sewage treatment and management., Skip the use of plastics, , Practice organic farming, , 33. List out the natural means to sink water to the soil., , , Forests, ponds, wetlands, sacred groves etc, , 34. Write short note about the importance of conservation of water., , , Nature provides enough water for us. We can solve the issues of water scarcity and drought if, , , , Allowing each drop of rain water to percolate at the place where it falls is the basic principle, , , , Harvesting rain water is the best way to solve the problem of water scarcity., , we make use of the rain water effectively., in water conservation., , 35. Which are the different types of rainwater harvesting?, , , a) Roof top rainwater harvesting: The level of the underground water can be raised either by, , , , b) Surface run-off harvesting: Includes all systems that collect and conserve surface run-off, , draining the rain water to the ground or by collecting it in storage tanks., , after a rainstorm or in intermittent streams, rivers, or wetlands for storage in open ponds and, reservoirs, , 36. List out the activities which help in collecting and storing the rainwater in the soil., , , Conservation of wet lands, , A+ BLOG- www.apluseducare.blogspot.com Whatsapp 9746544422, , Page 4

Page 5 :
A+ SOCIAL SCIENCE STD - VIII, , , Protection of forests, , , , Terrace farming, , , , Mulching, , , , Construction of check dams, , , , Construction of mud walls, , , , Digging rainwater percolation pits, , 37. Write a note on recycling of water., , , It is the process of converting waste water into water that can be reused for other purposes., , , , Recycling water also prevents pollution by decreasing the amount of waste water that must be, , Reuse may include irrigation of gardens and agricultural fields, discharged, , 38. Flow chart, , Prepared by:, , PRIYA B, HST(SS), CSHSS, THRISSUR, , More Resources, Visit https://apluseducare.blogspot.com/, Telegram Group: https://t.me/joinchat/ELv60hbE_g9Hvimlp0s1BA, , A+ BLOG- www.apluseducare.blogspot.com Whatsapp 9746544422, , Page 5