Identification of groundwater potential zone using analytical hierarchical process (AHP) and multi-criteria decision analysis (MCDA) for Bhavani river basin, Tamil Nadu, southern India

Abstract

The present study aimed to identify groundwater potential zones was involving the collection of both spatial and non-spatial datasets for water management practice. The Bhavani river basin groundwater is the major source for agriculture, domestic, industry, etc. The basin area is divided into lower and upper sub-basins of an area of 4207 km2. To delineate the Groundwater Potential Zone (GWPZ) ten thematic layers (geology, geomorphology, land use land cover, drainage and lineament density, slope, elevation, soil texture, rainfall, groundwater) were prepared using Arc GIS 10.3 software. The Analytical Hierarchical Process (AHP) based Multi-Criteria Decision Analysis (MCDA) was used to calculate the weightage value for each parameter. For parameter validation consistency index and consistency ratio were used. The identified groundwater potential zone was categorized into five classes based on the groundwater potential availability, as very high (1599 km2), high (1430 km2), moderate (547 km2), low (421 km2), and very low (210 km2). In the middle portion of the basin, 38% of the area falls under very good GWPZ and is followed by high (34%), moderate (13%), low (10%), and very low (5%) identified the different location of the basin. Further, GWPZ were classified based on firka and compared to the Public Work Department (PWD) 2011 and 2020 reports. From the report, 22 firkas are over-exploited from 2011 to 2020. In the present study GIS coupled with the AHP model gives accurate groundwater recharge zones. It's more helpful for drought risk assessment and planning recharge structures for agriculture engineers and government agencies.