Hydrochemical Characteristics of an Alluvial Aquifer : Chemical characterization of shallow groundwater of an extensively cultivated region in Central Ganga Plain, India

In dealing with groundwater system in alluvium-covered areas, straightforward clues may not be as simple due to masking of normal chemical alteration trends by anthropogenic influences. The present study analyses seasonal variations in groundwater chemistry and evaluates its suitability for drinking and irrigational uses. Study indicates Alkalis are distinctly far more abundant than Ca and Mg in both seasons. Although chemical differences between pre and post monsoon sets of samples are relatively trivial. Four major types of groundwater in the area are; HCO3-SO4 type, Cl-SO4 type, HCO3 type, and SO4 type. The unique chemical signature is attributable to ion exchange, carbonate dissolution, surface water-groundwater interaction and mixing of two or more types of groundwater. Aquifer vulnerability mapping, expressing the degree of risk for contamination, has been executed using modified DRASTIC model. Landuse-Landcover (LULC) pattern demonstrates significant impacts on groundwater quality. LULC parameters with unique rating and weight factors were clubbed with DRASTIC technique. This demarcate regions with greater degree to contamination and helps to enhance landuse planning.