Physicochemical assessment of water quality in the Hiran River at the confluence of Umrethi reservoir, Gir-Somnath

Abstract

A water quality assessment was conducted on the Hiran River across the 2022 - 2023 pre-monsoon, post-monsoon, and winter seasons to determine the effects of human activity and sewage disposal. The methodology involved testing a comprehensive suite of physico-chemical parameters including pH, Electrical Conductivity (EC), alkalinity, total hardness, key ions (calcium, magnesium, potassium, fluoride, chloride), nutrient loads (nitrate, nitrite, phosphate), and pollution indicators (Dissolved Oxygen, BOD, COD, salinity) at sites spanning the river from its source through rural, urban, and underdeveloped zones. The observed deterioration in water quality was chiefly linked to anthropogenic sources, such as unauthorized sewage and industrial runoff, a lack of proper site protection, and general urban runoff. The overall conclusion is that the Hiran River water is moderately polluted, though parameter ranges generally remained within acceptable limits.