An Integrated Approach for Determining the Anthropogenic Stress Responsible for Degradation of a Ramsar Site – Wular Lake in Kashmir, India

Abstract

Abstract During the last one and half decade, Kashmir valley's water bodies have been facing widespread water quality deterioration due to anthropogenic interferences' enhancement. In this context, the present study aims to monitor the water quality of Wular Lake by subjecting the acquired datasets to statistical approaches to infer status about distinctions and similarities among different sampling sites under investigation. The study integrated multiple data sets pertaining to analysis and assessment of water quality parameters, physicochemical concentration values, land use change systems, and water quality index through remote sensing and GIS environments. For limnological characterization of the lake, surface water quality data have been collected from seven randomly selected site pertaining to 22 physicochemical parameters, which were further analyzed. Settlements, agriculture, and horticulture in the lake's immediate vicinity were mapped using LISS IV satellite data of the year 2008–2019. The water quality index under this study comprises 12 measurable physicochemical parameters – pH, electrical conductivity, dissolved oxygen, total hardness, calcium content, magnesium content, nitrate nitrogen, chloride, turbidity, potassium, sodium and total alkalinity. Based on WQI values, the whole lake was divided into five zones, comprising least polluted zone (<50), moderately polluted zone (50–100), highly polluted zone (100–200), very highly polluted zone (200–300) and extremely polluted zone (>300). From this study, it has been found that WQI values for site S1, S2, S3, S4, S5, S6 and S7 are 179.62, 149.8, 160.61, 205.21, 200.5, 164.95 and 183.74, respectively. Thus, revealing that site S4 and S5 fall under the 'very highly polluted zone' and the remaining sites S1, S2, S3, S6 and S7 under 'highly polluted zone'. Land use category settlement record a growth rate of +50.79%, horticulture +25.96%, agriculture −11.8% and water body (open waters) −24.3% from the year 2008–2019. The reckless use of fertilizers, insecticides, pesticides in orchards and agricultural farms reinforced by concrete jungles in the immediate vicinity of Wular Lake have also enhanced the nutrient enrichment and deterioration of the water quality. Thus, escalating its scope towards the process of eutrophication.