Here is Question No. 81 a part of our series on UPSC Prelims 2018
Q81. Which of the following is/are the possible consequence/s of heavy sand mining in riverbeds?
- Decreased salinity in the river
- Pollution of groundwater
- Lowering of the water – table
Select the correct answer using the code given below:
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Answer: B
- Statement 1 is not correct: Depletion of sand in the streambed causes the deepening of rivers and estuaries, and the enlargement of river mouths and coastal inlets. It leads to decreased salinity in the river.
- Statement 2 is correct: The sediment in the mining site, if it contains toxic material due to long-term accumulation, will cause groundwater pollution.
- Statement 3 is correct: Riverbed becomes dry due to exposure to solar radiation, decreasing the surface and groundwater. It causes lowering of the water tables.
