Assessment of water and sediment quality of Gilsar Lake, Kashmir

Urbanization, modernization and population growth have increased the problem of eutrophication in the lakes. In the last few decades the Gilsar lake has undergone enormous changes and in turn has make it useless for domestic use and aesthetic view. The paper is an attempt to present the conditions of water and sediment quality of Gilsar lake. The samples were collected from four different locations viz. Gilsar Lake (inlet), Gilsar Lake (outlet), Nigeen Lake, and Tailbal Nallah (control site) in autumn 2018 and spring 2019. The variation of pH, electrical conductivity, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, total dissolved solids, calcium, magnesium, total hardness, ammonical nitrogen, nitrate nitrogen, total phosphorus, orthophosphate, potassium, sodium, sulphur, chlorides, oil and grease were determined in water. Sediment samples were analyzed for pH, electrical conductivity, organic carbon, available nitrogen, available phosphorous, available potassium, available calcium, and available magnesium. Standard procedures were followed for analyzing each parameter pertaining to both water and sediment. The concentrations of all water parameters were lowest at Tailbal Nallah except pH and DO. Similarly, the concentrations of sediment parameters were minimum at Tailbal Nallah except for pH. Water quality index showed marginal water quality at Tailbal Nallah (63.43) compared to Nigeen Lake (42.05), Gilsar Lake inlet (34.62), and Gilsar Lake outlet (34.48) which represented poor water quality. Sediment quality index showed a medium level of concern at Tailbal Nallah (58.40) and a high level of concern at Nigeen Lake (34.84) followed by Gilsar Lake inlet (31.17), and Gilsar Lake outlet (30.84). The water and sediment quality of Gilsar Lake was adversely affected and impaired by the discharge of domestic and agricultural wastes. The aforesaid study suggests a continuous analysis of water and sediment of Gilsar Lake which will provide information regarding pollution pattern and magnitude of pollution loading.