IMPACT OF SEAWATER INTRUSION ON COASTAL AQUIFER OF BHAVNAGAR, GUJARAT, INDIA USING GALDIT METHOD

Abstract

Salinity always exists in groundwater, but in variable amounts. In places where groundwater is being
pumped from aquifers that are in hydraulic connection with the sea, the induced hydraulic gradients may cause the
migration of salt-water from the sea towards the well. This study presents the application of GALDIT method to
evaluate the ground water vulnerability due to seawater intrusion in the Bhavnagar, Ghogha, Talaja and Mahuva
taluka region of the saurashtra coast line. The GALDIT index is based on four intrinsic hydro geological parameters,
one spatial parameter and one boundary parameter. The parameters of GALDIT index are: Ground water Occurrence
(aquifer type), Aquifer hydraulic conductivity, High ground water Level above the sea level, Distance from the shore,
Impact of existing status of sea water intrusion in the area, and Thickness of the aquifer GALDIT index is calculated
after deciding the weightage, range and rate of each factor. GALDIT map of Bhavnagar coastal area indicated that
most of the coastal zone is vulnerable to salinity ingress.