Deciphering artificial groundwater recharge suitability zones in the agricultural area of a river basin in Andhra Pradesh, India using geospatial techniques and analytical hierarchical process method

Abstract

The aim of the present study is to decipher artificial groundwater zones in the agricultural area of the Varaha River basin in the Visakhapatnam district, Andhra Pradesh, India, using a combination of the Geospatial Techniques (remote sensing and GIS) and Analytical Hierarchical Process (AHP) method. For identification zones suitable for recharging aquifers, the thematic maps on determinant factors (n = 9) including rainfall, slope, drainage, soil cover, geomorphology, geology, lineaments, seasonal fluctuation of groundwater levels, and land use/land cover were considered and prepared them, using Landsat Satellite Imageries and Shuttle Radar Topography Mission Digital Elevation Model (SRTM DEM). These factors were classified into different sub-classes for integration by assigning appropriate weights (1 to 5) and ranks (4 to 35) for each given factor based on their respective groundwater recharge contributions, using the AHP method. The coefficient of determination, regression analysis, and ANOVA tests were performed prior to integrating the layers for the degree of accuracy in the prediction output, which supports the result of the AHP method. Finally, ArcGIS was used to integrate all thematic layer maps to delineate artificial groundwater recharge zones. These zones included very low artificial recharge zone (4.60%), low artificial recharge zone (18.33%), moderate artificial recharge zone (50.40%), high artificial recharge zone (23.43%), and very high artificial recharge zone (3.24%) to replenish groundwater resources. Most study area (77.07%) falls under moderate to very high artificial groundwater recharge zones. The study recommends the suitable recharge structures (roof-top rainwater harvesting, check dams, percolation tanks, and injection wells) and irrigation efficiency methods (sprinklers and drips irrigations) to augment groundwater quantity and thereby improve groundwater quality. Therefore, this study helps to expand the practice of irrigation and increase agricultural income for better living conditions of rural communities.