1. Describe with suitable sketches any two depositional landforms of the river.
Ans: i. Flood plain:- In the lower course of a river heavy deposition of sand, silt, stones, etc. takes place on the river bed. When a flood occurs during the rainy season widespread deposition of alluvium takes place which fills up the low-lying areas of both the banks of a river and builds up plains. These are known as flood plains.
ii. Natural Leeves:- On the lower course of a river, active deposition takes place along the banks of an old river when it is in flood. After a long period of such deposition, the river banks are raised. These raised banks of a river are known as natural levees.
2. Mention three measures to prevent desertification.
Ans: i. Employ the people to grow seedlings and transfer these to severely deforested areas during rainy season.
ii. Fixating soil by creating shelterbelts, windbreaks, etc. Windbreaks are made from trees and bushes that are planted across the path of the wind.
iii. Sand fences can be used to control the drifting of soil and sand erosion.
3. Differentiate between eastern and western coastal plains of India.
Ans: Eastern Coastal Plain:-
i. The east coast plain lies along the east coast of India and is washed by the Bay of Bengal.
ii. The eastern coast is smooth and unfit for making ports.
iii. This coastal plain receives comparatively low rainfall.
Western Coastal Plain:-
i. The west coast plain lies along the west coast of India and is washed by the Arabian sea.
ii. The west coast is broken and intended and suitable for ports.
iii. This coastal plain receives heavy rainfall.
4. Describe the effects of excessive extraction of groundwater
Ans: i. Reduced surface water supply, as groundwater and surface water are connected with each other.
ii. Lowering of the water table.
ii. Land subsidence occurs when there is a loss of support below ground.
5. Why are Aeolian processes most active in desert region?
Ans:
6. How does global climatic change affect the Sundarbans?
Ans: i. Increasing temperature:- The temperature of waters in the Sunderbans has increased which causes harm to its aquatic life and the health of the mangrove forests.
ii. Rising sea level due to melting of ice sheets has led to submergence of various islands in Sunderbans.
7. Why is rainwater harvesting necessary?
Ans: Rainwater harvesting is necessary because it recharges groundwater by capturing and storing rainwater. Rainwater can be stored on rooftops, in abandoned dug well, dams, small rivulets, etc. Rainwater is mostly free from harmful chemicals, which makes it suitable for irrigation purposes.
8. How does El Nino and La Nina affect Indian monsoon?
Ans: El Nino is associated with drought or weak monsoon, while La Nina is associated with strong monsoon and above-average rains, and colder winters.
