Abstract:
The use of isotopes in hydrology is now not new to the scientific community. But, most of the people understand that only artificially produced radio-isotopes can be used for various hydrological investigations while the environmental isotopes which comprise stable and radioactive isotopes both have numerous applications in the field of hydrology, besides the fact, that the availability of these radioisotopes is free of cost and also they not pose any threat to the human being from health hazard point of view. The only negative point associated with the use of environmental isotopes is that, costly instrumentation is required
their analysis in comparison to artificial radioisotopes.
The use of environmental isotopes is also not very popular in India alike in developed countries, but, few of the organisation like BARC, Bombay and NGRI, Hyderabad are using there isotopes in a very limited way.. However, the expertise required for the use of environmental isotopes in hydrology is still to be developed. The present report deals with the basic concepts of environmental isotopes, their variations in nature, applications of environmental stable and radioactive isotopes in the field of hydrology, detection and measurement techniques and gaps, the present status of the use of environmental isotopes in India has also been described in brief.