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:

1. 1 only
2. 2 and 3 only
3. 1 and 3 only
4. 1, 2 and 3

Explanation

Consequence 1 is incorrect but Consequences 2 and 3 are correct

• Heavy sand mining in riverbeds disturbs the natural river ecosystem and hydrogeological balance. It often leads to lowering of the water table due to excessive removal of sand, which reduces groundwater recharge capacity. It can also result in pollution of groundwater as deeper layers get exposed and contaminants seep in more easily. However, heavy sand mining does not decrease salinity; instead, it may increase salinity, especially in coastal areas due to seawater intrusion.

Answer: (b) 2 and 3 only; Difficulty Level: Easy