Groundwater mining in coastal areas can result into:

Options

A. increase in the salinity of groundwater
B. decrease in the toxicity of ground water
C. decrease in the salinity of ground water
D. increase in the water table

Answer

### Step-by-Step Solution:

1. **Understanding Groundwater Mining**:
- Groundwater mining refers to the process of extracting or withdrawing groundwater from aquifers, which are underground layers of water-bearing rock.

2. **Identifying Coastal Areas**:
- Coastal areas are regions where land meets the ocean. These areas often have specific geological formations that contain aquifers.

3. **Effects of Groundwater Mining in Coastal Areas**:
- When groundwater is excessively extracted in coastal regions, it can lead to several environmental issues. One of the primary concerns is the alteration of the natural balance between freshwater and saltwater.

4. **Saltwater Intrusion**:
- As groundwater is removed, the pressure that keeps seawater at bay decreases. This can cause saltwater from the ocean to move inland, a phenomenon known as saltwater intrusion.

5. **Consequences of Saltwater Intrusion**:
- Saltwater intrusion can contaminate freshwater aquifers, making the water unsuitable for drinking and irrigation. This can have significant impacts on agriculture, drinking water supplies, and the overall ecosystem.

6. **Summary of Results**:
- Therefore, groundwater mining in coastal areas can lead to saltwater intrusion, which adversely affects the quality of groundwater and can have long-term ecological and economic consequences.

### Final Answer:
Groundwater mining in coastal areas can result in saltwater intrusion, which contaminates freshwater aquifers and affects water quality and availability.

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