Hydrochemical evaluation of surface water quality of Sutlej river using multi-indices, multivariate statistics and GIS

摘要

The water quality of Sutlej river in Indian Punjab is getting deteriorated due to expansion of agricultural, industrial and recreational activities in the region. Many studies have evaluated the water quality of Sutlej river around the stretches of contaminated drains confluence with the river, but there are very few studies in which hydrochemistry of surface water of the river has been studied from the entry point of Sutlej river in Indian Punjab to its tail end when it leaves the country. Surface water samples (n = 97) were collected from the river during May 2019 and analyzed for pH, electrical conductivity, carbonate, bicarbonate, chloride, calcium, magnesium, sodium, potassium, nitrate and sulfate in the laboratory using the standard protocols. Results showed that total alkalinity, total hardness, sodium, potassium, chloride and nitrate were higher along the transboundary of the river. Water samples of the river are mainly Ca-Mg-HCO3 and Ca-Mg-Cl-SO4 types. Spatial distribution of all the parameters showed higher concentration of cations and anions along transboundary of the river. Principal component analysis, Heat map analysis and non-metric multidimensional scaling showed that water quality along the transboundary of the river are having different signature from the other zones of the river due to variations in chloride, sodium, total alkalinity and total hardness in water. Health risk assessment due to nitrate in water also showed that possibility of hazard was higher in the areas along transboundary of the river and children are more prone to health risks followed by women and men. Water quality along transboundary of the river followed by the area from the confluence of contaminated drain with river to transboundary along with localized spots in the river are not suitable for irrigation and drinking purposes. These results suggest that management of anthropogenic pressure, implementation of wastewater management and other strategies are required to improve the water quality of river.