(i) Groundwater:

→ Groundwater is the water that soaks into the soil from rain or other precipitation & moves downward to fill cracks & other, opening in beds of rocks & sand.

→It is therefore a renewable resource, although renewal rates vary greatly according to conditions.

→ It also is an abundant natural resource.

→ Of all freshwater in the world (excluding polas ice. caps), 95% is groundwater.

(ii) Hydrology:

→ Hydrology is the science that encompasses the occurrence, distribution, movement & properties of the Water of the earth & their relationship with the environment within each phase of the hydrologic cycle.

→ The water cycle, or hydrologic cycle, is a continuous process by which water is purified by evaporation of & transported from the earth's surface (including the oceans) to the atmosphere & back to the land & Oceans.

(iii) Hydrogeology:

→ Hydrogeology is the area of geology that deals. with the distribution & movement of groundwater.


3. Give an account of Groundwater resources. india with special reference to state of gujrat.

An account of Groundwater resources of indies;

BCM Billion Cubic Meter
Groundwater Resources Assessment
 2017
(i) Annual replenishable ground water
Resources.		 432 bcm
(ii) Net annual ground water availability. 313 bcm
(iii) Annual groundwater draft for irrigation, domestic & industrial uses. 249 bcm
(iv) Stage of Groundwater development.  63%

An account of Groundwater Resources of Gujrat :

Groundwater Resources Assessment 2017
(i) Annual replenishable groundwater
resources. 		 15.81 bcm
(ii) Net annual groundwater crvailability  15.02 bcm
(iii) Annual groundwater draft 11.49 bcm
(iv) stage of ground water development. 76%


4. Key difference Between surface water and Groundwater. 

Surface Water
 Ground Water
(i) The water found on the surface of the earth is known as surface water. The water that is located below the earth's surface is reffered to as ground water. 
(ii) The water has low mineral content & is more contaminated. The water is less contaminated as the rocks above the ground water level work as filters.
(iii) Due to less minerals it is also known as soft water. Due to minerals picked during the process of filteration via the rock it's considered as hard water.
(iv) It is easier to extract. Surface water. It is comparatively Difficult to extract ground Water.
(v) The sources for surface water are stream's lakes, rivers.
etc. 		 The source here is the water that is seeps through the soils & is filtered through the different layers of earth f is stored in porous soil & rocks.
(vi) They used for irrigation, cleaning etc purpose. They need to be pumped out of the ground.