Seawater intrusion mapping using modified GALDIT indicator model

Abstract

Continued human interference into the coastal hydrologic system has led to the pollution of the coastal groundwater aquifers by salt water. The groundwater pollution incidents due to salt-water intrusions have inc reased many folds in the last couple of decades. The indirect effect of human interference would be in the form of climatic changes, which will lead to the rise in sea levels. This rise in sea levels has direct impact on the extent of seawater intrusion in the coastal and island aquifers. Therefore, it is essential to develop a methodology to assess and map the probable potential areas of seawater intrusion by standard scientific method, taking in to account the expected sea level rise. A new method of aquifer vulnerability mapping GALDIT has been successfully used in assessing the impact of sea-level changes on the extent of seawater intrusion in the coastal aquifers. The method has been derived based on both the intrinsic aquifer properties and the dynamic groundwater / seawater level changes and hen ce provides measure of aquifer vulne rability of an area to seawater intrusion problems.