Identification of groundwater potential zones using geospatial approach in Sivagangai district, South India

The study area, Sivagangai district is considered as one of the drought prone districts of south India. Hence, there is a need of study to identify the groundwater potential zones in this region. Firstly, thematic layers (geomorphology, geology, drainage, lineament, slope, and soil) were produced using satellite images in Arc GIS platform. Analytical hierarchy processes (AHP) was done to compute the weightage for each layer with respect to the relative importance of groundwater potential index. All the thematic layers were reclassified according to their water-bearing properties with the weightages derived by AHP. The consistency of derived weightage is evaluated as 0.082 which is below the standard consistency ratio of 0.1 and is consistent. Through overlying analysis of all thematic layers, a groundwater potential map was produced using geographic information system (GIS). Four major groundwater potential zones were identified as very good, good, moderate, and poor. Majority of the study area were classified as moderate (38.2%) and good (30.8%) groundwater potential zones. Groundwater level map was used to validate the groundwater potential zone. The groundwater potential map can be used to identify the appropriate locations for artificial recharge. Artificial recharging structures such as percolation ponds, recharge shaft, and farm ponds have to be implemented to improve the water level in the region. The outcome of this study strengthens the knowledge of geospatial analysis for groundwater vulnerability and also allows policymakers in this drought-prone area to sustainably manage water supplies.