Groundwater quality evaluation for drinking and irrigation using analytical hierarchy process with GIS in semi critical block of Chhattisgarh, India

Groundwater plays a crucial role in achieving sustainable development across various dimensions. Groundwater resources comprise of two integral aspects namely quality and quantity which are interconnected and important to comprehend and manage efficiently. The groundwater quality in the semi critical blocks of Chhattisgarh State is deteriorating, creating a health risk for the local population. In current study, ten representative groundwater samples were obtained and analyzed physiochemical parameters such as pH, EC, TDS, TH with major anions and cations for both pre and post monsoon period of 2020 for Patan block of Chhattisgarh. Fluoride and Nitrtae concertration at some location has been found beyond permissible limit of BIS. Hydrochemical evaluation of groundwater samples were carried out by Piper and Gibbs diagrams. Groundwater quality index (GWQI) and irrigation water quality index (IWQI) were prepared based on a combination of Geographical Information System (GIS) and Analytic Hierarchical Process (AHP) for drinking and irrigation uses, respectively. AHP is known for handling quantitative and qualitative criteria, providing a structured framework and allowing for expert knowledge and subjective judgments. To assess maps of WQI with regards to their applicability for drinking and irrigation uses, six parameters/indices were selected and their weights were calculated using the AHP. The GWQI and IWQI maps were prepared using a weighted overlay technique in GIS. This shows that 6.11%, 85%, and 8.89% of total area falling into "good", "moderate" and "poor" classification for groundwater for drinking purposes, respectively. Similarly, the IWQI shows that 96.53% and 3.47% of the area fall into the categories of suitable and doubtful, respectively. The preponderance of groundwater within the region is drinkable and appropriate for agriculture.