Question 53 from UPSC CSE 2018 - Environment

Question

Which of the following is/are the possible consequence/s of heavy sand mining in river beds?
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:

IASCODEX · Accepted Answer

Correct Option: B. 2 and 3 only

Strategy: Focus on the logical outcomes of sand removal: it acts as a natural filter and repository. Its removal leads to pollution and drops in the water table. Importantly, it does not decrease river salinity--if anything, it can increase the risk of salinity ingress. Therefore, rule out option 1 and retain options 2 and 3.

Key Info: Sand mining, the excavation of sand from riverbeds or beaches primarily for construction, has significant environmental consequences. Sand naturally acts as an aquifer and filter, crucial for river ecosystems and water quality. Excessive mining destabilizes riverbeds, increases turbidity, and diminishes filtering capacity, leading to several issues:

*   **Lowering of the water table**: Loss of sand reduces groundwater recharge, causing the water table to drop and wells to dry.
*   **Pollution of groundwater**: Increased turbidity and the removal of sand's filtration layers allow contaminants to seep into groundwater, degrading water quality.
*   **Salinity impact**: While sand removal does not decrease river salinity, it can increase saline water intrusion, particularly in coastal rivers, often worsening the situation.

Additional risks include riverbank erosion, habitat destruction for aquatic life, threats to infrastructure like bridges, and the loss of community livelihoods. Sand mining is regulated by the Environmental Protection Act, various local environmental statutes, and guidelines from the Ministry of Environment, Forest and Climate Change (MoEF&CC).

IASCODEX · Answer

Option A: 1 only

IASCODEX · Answer

Option C: 1 and 3 only

IASCODEX · Answer

Option D: 1, 2, and 3

Which of the following is/are the possible consequence/s of heavy sand mining in river beds? Decreased salinity in the river Pollution of groundwater Lowering of the water-table Select the correct answer using the code given below:

Which of the following is/are the possible consequence/s of heavy sand mining in river beds?

Decreased salinity in the river

Pollution of groundwater

Lowering of the water-table
Select the correct answer using the code given below: