It refers to the efficient management and conservation of surface and groundwater resources. Which concept is being referred here?

watershed management

The correct answer is Option 3: watershed management

Watershed management basically refers to efficient management and conservation of surface and groundwater resources. It involves prevention of runoff and storage and recharge of groundwater through various methods like percolation tanks, recharge wells, etc. However, in broad sense watershed management includes conservation, regeneration and judicious use of all resources – natural (like land, water, plants and animals) and human with in a watershed. Watershed management aims at bringing about balance between natural resources on the one hand and society on the other.

Let's look at why the other options are less accurate:

Water management: While broad, it doesn't necessarily encompass the holistic, integrated approach to both surface and groundwater conservation that watershed management does.

River basin management: This focuses specifically on the management of a river and its tributaries, while a watershed is the area of land that drains into a specific point. So river basin management is a subset of watershed management.

Irrigation management: This is a more specific area dealing with the efficient use of water for agricultural purposes. It doesn't inherently cover the broader scope of surface and groundwater conservation.