Question

The conjunctive use of water in a basin means:-
1. Combined use of water for irrigation and hydropower generation
2. Use of water by farmers cooperatives
3. Use of water for irrigating both Rabi and Kharif crops
4. Combined use of surface and ground water resources

Answer 1

Correct Answer - Option 4 : Combined use of surface and ground water resources

The conjunctive use of water means combined use of surface water resources & groundwater, in a unified way, to optimize resource and minimize adverse effects of using a single source.

During wet years, when more surface water is available, surface water is stored underground by recharging the aquifers with surplus surface water. During dry years, the stored water is available in the aquifer system to supplement or replace the diminished surface water supplies.

By doing so, it has certain advantages:

1. Ease of transport of water by a river or channel.
2.  Aquifer is used to store surface water when there is an excess of it and  it would otherwise be wasted, say in winter.
3. River is used to transport water from the aquifer to where it is needed when river discharge is too low on its own as often happens in summer its own, as often happens in summer
4. Conjunctive use can reduce abstraction from rivers when discharge is low by using groundwater instead.
5.  Problems of water logging/ groundwater over use reduced.