Question

"It is important to make small check dams across the flooded gullies". Which of the given reasons is correct?
(i) Hold water for irrigation
(ii) Prevent soil erosion
(iii) Recharge groundwater
(iv) Hold water permanently

• A. (i) and (iv)
• B. (ii) and (iii)
• C. (iii) and (iv)
• D. (ii) and (iv)

Answer 1

The correct option is B

(ii) and (iii)

The correct option is B.

Explanation for the correct option:

1. The "check dams" constructed across seasonally flooded gullies are used for irrigation while also preventing soil erosion.
2. The main goal, however, is to recharge the groundwater beneath, which spreads out to recharge wells.
3. A check dam placed in a ditch, swale, or channel interrupts the flow of water and flattens the channel gradient, reducing velocity.
4. A gully is a landform formed by running water harshly eroding into the soil, typically on a hillside.
5. Gullies reduce farmland productivity wherever they cut into the land and produce sediment that can clog downstream water bodies.
6. Any soil erosion, such as gullies, that has already formed can be addressed by the construction of dams or obstructions.

Explanation for the incorrect options:

Option A:

1. The check dams constructed across gullies that flood seasonally is utilized for irrigation.
2. They do not hold water permanently.

Option C:

1. The primary objective of check dams is to recharge the groundwater below, which then extends out to recharge wells.
2. They do not hold water permanently.

Option D:

1. Soil erosion is prevented using check dams.
2. They do not hold water permanently.

Final answer: “It is important to make small check dams across the flooded gullies'' to prevent soil erosion and recharge groundwater.