Quality evaluation of water resources through WQI, IWQI and chemometric assessment in agro-practice areas of Central India

Abstract

The present study examines the water quality of the Deobhog area in Central India vis-à-vis the Water Quality Index (WQI) and Irrigation Water Quality Index (IWQI) on 70 groundwater and 30 surface water samples. The concentration of major cations (Na⁺, Ca²⁺, Mg²⁺, and K⁺), anions (HCO₃⁻, Cl⁻, NO₃⁻, SO₄²⁻, and F⁻), and heavy metals (Mn, Fe, Cu, Pb, and U) in groundwater was compared with the drinking water norms and used to evaluate the WQI in the area. Multivariate statistical analysis has been done on major ions and trace element chemistry for all water sources, and hydrogeochemical facies are visualised through Piper trilinear plots. Spatial distribution maps of groundwater quality parameters indicate elevated levels of EC, Ca²⁺, Mg²⁺, HCO₃⁻, NO₃⁻, and F⁻, whereas among the heavy metals, Fe is observed to be present at higher concentrations. The WQI indicates that the quality of groundwater in the Deobhog area is moderate and alarming in a few pockets and is suitable only in the south-eastern and western parts. Calculated IWQI shows groundwater resources can be effectively utilised to meet the good-quality irrigable water demands in areas having poor surface water quality. Chemometric assessment reveals that carbonate dissolution, ion exchange, and silicate weathering are responsible for major ion concentrations in all sources of water with evidence of contaminants from agricultural sources.