S. Kaliraj

Evaluation of multiple environmental factors for site-specific groundwater recharge structures in the Vaigai River upper basin, Tamil Nadu, India, using GIS-based weighted overlay analysis

The present study investigates the groundwater recharge potential zone and suitable sites for artificial recharge structures in the River Vaigai upper basin, Theni district, Tamil Nadu, using GIS-based multi-parameter weighted overlay method. The study area experiences severe groundwater scarcity despite having high rainfall and runoff. Therefore, an integrated remote sensing and GIS technique is used to assess the permeability and infiltration characteristics of the area and demarcate the recharge potential zones. The recharge potential zones and site-specific artificial recharge structures have been demarcated based on the weights of multiple parameters based on their permeability and infiltration capacity to groundwater recharge. The groundwater recharge potential map shows the twenty suitable sites for artificial recharge structures such as percolation ponds, loose rock check dams, and water absorption trench (WAT) in various parts of the study area. The effective recharge practices such as percolation ponds and check dams are highly suitable for gentle-sloped barren and agricultural plains in the northwestern and northeastern parts. Whereas, the barren valley fill, bajada and streams intersecting lineaments along the middle-eastern and central part are suitable for constructing WAT and check dams. These water-harvesting features can improve the groundwater scenario of the study area and groundwater augmentation is possible in future with the help of advanced techniques like remote sensing and GIS.