Groundwater quality assessment for irrigation by adopting new suitability plot and spatial analysis based on fuzzy logic technique

• Published in: Environmental research 2022-03, Vol.204 (Pt A), p.111729-111729, Article 111729
• Main Authors: S., Chidambaram, M.V., Prasanna, S., Venkatramanan, M., Nepolian, K., Pradeep, Panda, Banajarani, C., Thivya, R., Thilagavathi
• Format: Article
• Language: English
• Subjects: Drinking Water - analysis; Environmental Monitoring; Fuzzy GIS; Fuzzy Logic; Geochemistry; Groundwater; India; Irrigation water quality; New irrigation suitability plot; NPK fertilizers; South India; Spatial Analysis; Water Pollutants, Chemical - analysis; Water Quality; Water Supply
• ISSN: 0013-9351; 1096-0953
• DOI: 10.1016/j.envres.2021.111729

This study was focused on identifying the region suitable for agriculture-based, using new irrigation groundwater quality plot and its spatio-temporal variation with fuzzy logic technique in a geographic information system (GIS) platform. Six hundred and eighty groundwater samples were collected during pre, southwest, northeast, and post monsoon periods. A new ternary plot was also attempted to determine the irrigation suitability of water by considering four essential parameters such as sodium adsorption ratio (SAR), permeability index (PI), Sodium percentage (Na %), and electrical conductivity (EC). The derived ternary plot was the most beneficial over other available plots, as it incorporated four parameters, and it differs from the US Salinity Laboratory (USSL) plot, such that the groundwater with higher EC could also be used for irrigation purposes, depending on the Na%. The ternary plot revealed that the groundwater predominantly manifested good to moderate category during post, northeast, and southwest monsoons. The assessment with the amount of fertilizer used during the study period showed that the NPK fertilizers were effectively used for irrigation during monsoon periods. Spatial maps on EC, Kelly's ratio, Mg hazard, Na%, PI, potential salinity (PS), SAR, residual sodium carbonate (RSC), and soluble sodium percentage (SSP) were prepared for each season using fuzzy membership values, integrated for each season. A final suitability map derived by an overlay of all the seasonal outputs has identified that the groundwater in the western and the eastern part of the study area are suitable for agriculture. The study recommends cultivation of groundwater-dependent short-term crops, along the western and northern regions of the study area during the pre-monsoon season. •A new geochemical plot for irrigation suitability was derived.•Fuzzy logic spatial technique was adopted for demarcating irrigation suitable zone.•Seasonal impact of NPK fertilizers on groundwater was determined.•Areas suitable for groundwater dependent short term crops were identified.