Application of GALDIT Approach for Sea water intrusion vulnerability assessment: A case study of Bhubaneswar and its buffer zone, Odisha

Salt water intrusion is a growing concern for coastal and nearby areas. The application of ground water and its over exploitation is the main cause of sea water intrusion. Ground water is being pumped from the aquifers and those aquifers are hydraulically connected with sea. The pumping induces a hydraulic gradient which cause the moving of sea water towards ground water in that excessive pumping area and it aggravates due to reduction of fresh water inflows. As the use of pure ground water is highly essential for developmental uses, it is necessary to determine the sea water intrusion particularly for coastal areas and its nearby cities. The vulnerability of sea water intrusion has been studied at Bhubaneswar city, the capital of Odisha, India including its buffer zone upto the coastal city Puri, using GIS based GALDIT method. The six important factors those are, Ground water occurrence (G) ; Hydraulic Conductivity (A) ; Depth of ground water level (L) ; Distance from Shore (D) ; Impact of existing salt water intrusion (I) ; Aquifer thickness (T) are taken into consideration. The data are ranked as per their contribution to salination and the thematic maps are overlayed using GIS in order to make the vulnerability analysis. The study shows that, the Bhubaneswar city has very less vulnerability to sea water intrusion upto the time period of analysis.