Which of the following is/are the possible consequence/s of heavy sand mining in riverbeds ?
- 1.Decreased salinity in the river
- 2.Pollution of groundwater
- 3.Lowering of the water-table
Select the correct answer using the code given below :
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Answer: B. Statement 1 is wrong: sand mining can let seawater enter river mouths, raising salinity, not lowering it. Statement 2 is correct: removing sand, which filters water, can pollute groundwater. Statement 3 is correct: deepening the riverbed lowers the water table. So 2 and 3.
Watch for: Students assume any change in salinity is possible, but the effect is an increase.
Why the other options are wrong
- A. Wrong because sand mining does not decrease river salinity.
- C. Wrong because salinity tends to rise, not fall.
- D. Wrong because statement 1 is false.
Source to check: Ministry of Environment, Forest and Climate Change, 'Sustainable Sand Mining Management Guidelines', 2016
Answer from the official UPSC key. Written and fact-checked by AI against the official key. Spotted a mistake? Report it.