Theme 2-16-Isotope hydrology - present status and future prospects in India

Abstract

The application of isotopes to hydrology is comparatively new but the vast potential of isotope techniques to understand the various complicated hydrological processes has increased the interest among the scientific community. Several research institutions/ organisations in India are presently using different isotopic techniques for obtaining useful information on the different components of the hydrological cycle. Many hydrological studies have been carried out in parts of Andhra Pradesh, Gujarat, Haryana, Karnataka, Kerala, Maharashtra, Pondicherry, Punjab, Rajasthan, Sikkim, Tamilnadu, Uttar Pradesh and West Bengal states of India using isotopes.

There are number of organisations/institutions in India which are engaged in various types of hydrological studies using isotopes. The detection of isotopes in different facets of hydrological cycle is now possible in ultra low concentration with very high precision and reliability. It has encouraged the scientific community to increasingly use these techniques.

Although extensive work has been carried in past few decades in India using isotope techniques but still there is a need to exploit the potential of these techniques. The useful hydrological information like, the contribution of different recharge sources and location of recharge zones for deeper aquifers, possibility to recharge the groundwater bodies artificially and sources and extent of groundwater contamination etc. can be obtained using isotope techniques. This may be helpful in finding possible solutions for a number of hydrological problems particularly in case of large and densely populated urbanised cities where the water related problems are becoming crucial. In addition, there are number of other potential areas like, artesian wells in Tarai and Bhabhar Belt, water balance and sedimentation in water bodies, surface water and groundwater interaction in case of perennial rivers, stream flow measurement in mountainous areas, seepage and leakage from water bodies, snow and glacier studies, flow of soil moisture through unsaturated zone and recharge to aquifers, sea water intrusion and salinization mechanism of groundwaters, soil erosion and watershed management studies and evaluation of effectiveness of artificial recharge measures etc. which can be taken up on priority basis for the studies using isotope techniques in our country.

This paper provides a review of the isotope hydrological studies carried out in India in past four decades, environmental isotope measurement facilities available and the list of the organisations which actively involved in hydrological studies using isotopes in India. An effort has also been made to focus various important studies that can be carried out in India in order to understand the various hydrological problems that are presently being faced and many those that will be faced in next couple of decades.