AN INTEGRATED HYDROGEOCHEMICAL AND ISOTOPIC STUDY OF SALINITY AFFECTED AREA IN DISTRICT AMRAVATI, MAHARASHTRA

Abstract

Availability of potable groundwater in areas charcaterised by low rainfall is a prime requisite for mankind. If, the available groundwater is not of suitable quality, then the cost of providing drinking water to the burgeoning population inhabiting the area tends to be prohibitive. In such cases, the relief measures should include efforts to improve the groundwater quality. This requires a good understanding on the causes for such poor quality of groundwater in the area in question. Parts of the area falling under Puma river basin in Amravati distict of Maharashtra is characterised by the groundwater salinity problem. The Groundwater Surveys and Development Agency of Maharashtra State has taken up an "Induced Recharge Project", whereby the river water of good quality is intended to be used for recharging the groundwater in the aquifers adjoing the river courses. A large number of wells have been drilled along the river banks and operated to create a reverse groundwater level gradient. In the present study, the problem of salinity in parts of Puma river basin has been addressed with two major objectives viz, to understand the causes of salinity of groundwater in the study area and to evaluate the performande of the wells drilled and being operated under an ongoing induced recharge project of the GSDA. In order to meet the above objectives, available information on the hydrogeology, hydrochemistry, soil characteristics, hydrometeorology, land use pattern, and hydrology have been collected from differen sources. The data sources include published and unpublished literature, goveniment records etc. Further, a set of 37 water samples from different rivers draining the study area and groundwater have been collected. The samples were subjected to hydrochemical analyses for major ions such as Cat, Mg2+, Nat, K+, HCO3-, S042, and Cl-. Analyses for trace elements such as Sr and Li were also carried out. About 20 samples of rivers, groundwater and rainfall were analysed for environmental tritium. Further, about 37 samples collected from different rivers and groundwater of the study area were analysed for stable isotopes &18O and &D..