GROUND WATER VULNERABILITY ASSESSMENTOF KODOOR RIVER BASIN BY INTEGRATED DRASTIC METHOD

Abstract

Groundwater vulnerability assessment techniques are useful tools in groundwater management. The purpose of the study is to assess the groundwater vulnerability of Kodoor river basin in Kerala by DRASTIC model and to modify the model to suit the regional scale by incorporating the land use and/ or land cover (LULC) pattern of the area of study in it to produce DRASTICA model. The interdependence of the nitrate concentration data and vulnerability indices from DRASTIC and DRASTICA models were calculated. Correlation coefficient values obtained for DRASTIC and DRASTICA model is 0.21 and 0.38 respectively which shows that the modified DRASTICA model suits the study area better. The study area was grouped into three zones based on the grades of vulnerability. The study also includes the sensitivity analysis of the DRASTICA model. The map removal sensitivity analysis and single parameter sensitivity analysis were carried out to validate the model results.