Central Ground Water Board carries out regional hydrogeological
studies which provide information on ground water occurrence
in different terrains and are essential for future planning
of ground water development and management. First level (Systematic)
surveys on 1:50,000 scale has been completed for the entire
country by March, 1991.This has generated basic information
on various hydrogeological parameters. Ground water being
replenishable and dynamic in nature, it becomes essential
to conduct periodic hydrogeological studies (Reappraisal hydrogeological
surveys) to assess the qualitative and quantitative changes
in the ground water regime in time and space. Approximately
2 lakh sq.km. area in different parts of the country is covered
under periodic studies every year. These studies help in reassessing
changes in ground water scenario consequent to various development
activities.
Photogeological and remote sensing data is extensively used
for hydrogeological purpose viz. source finding to demarcate
the area and sites suitable for ground water development.
Areas remaining hitherto inaccessible have also been surveyed
and these techniques have proved very useful in understanding
ground water scenario on regional scale. Advanced surface
geophysical methods are used as source finding technique.
In hard rock terrains, this technique has proved indispensable
to decipher sub-surface saturated fractures or situations
suitable for ground water occurrence.
CGWB renders assistance to various urban, defence and public
sector establishments to solve their immediate water supply
problems by selecting suitable sites for construction of ground
water abstraction structures. The Board has carried out detailed
surveys in Lakshwadeep and Andaman and Nicobar Islands to
delineate shallow fresh ground water lenses and deep ground
water zones in an otherwise saline water environment. Central
Ground Water Board has also helped the Rajiv Gandhi National
Drinking Water Mission in identifying suitable ground water
sources for drinking water supply.
Ministry
of Water Resources