UPSC CSE Prelims
Question 19
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
View correct answer and explanation
Correct answer: B
Correct Option: B
Explanation: Excess riverbed sand extraction can destabilise the channel and aquifers, contaminate groundwater and lower the local water table. A general decrease in river salinity is not an established consequence.
Statement/Pair-wise Analysis:
Statement/Item 1: Incorrect - Riverbed sand removal does not generally or necessarily reduce salinity.
Statement/Item 2: Correct - Changed river–aquifer interaction and disturbed sediments can worsen groundwater pollution.
Statement/Item 3: Correct - Over-extraction can lower adjacent groundwater levels and damage wells.
Option-wise Analysis:
A: Incorrect - includes incorrect statement/item 1; omits correct statement/items 2, 3.
B: Correct - includes all and only the true statements/items.
C: Incorrect - includes incorrect statement/item 1; omits correct statement/item 2.
D: Incorrect - includes incorrect statement/item 1.