MULTIVARIATE STATISTICAL ANALYSIS OF PHYSICO-CHEMICAL WATER QUALITY PARAMETRS OF DAL LAKE

Abstract

Dal Lake is one of the foremost Himalayan lakes of the Kashmir Valley. Being an urban lake, it is the economic backbone of Srinagar city’s tourist commerce, which beacons travellers from all over. Unfortunately the lake is a victim of proliferating anthropogenic pollution and is subjected to a steadily expanding rate of eutrophication and siltation. Considering the significance of this world acclaimed water body by way of Kashmiri human resource advancement and economic development, the main objectives of this study was long term assessment of water quality of the Dal Lake by using multivariate statistical tools in addition to developing a Water Quality Index which can be used by the regional monitoring body i.e. Jammu And Kashmir Lakes And Waterways Development Authority to convey the water quality status for the development of lake water quality. The period of water quality assessment was 5 years from September 2010 to August 2015. Significant spatio-temporal variability in most parameters indicated substantial spatio temporal variations. From the principal component analysis it can be construed that the lake water quality is mainly influenced by waste water discharge and agricultural run-off in the form of proliferation of nutrients like nitrate-nitrogen, ammonium-nitrogen, phosphates and chlorides. From the spatial cluster analysis it is clear that the Central Site Nigeen, Outlet Sites of Habak and Outlet Site of Hazratbal are the most polluted sites of Dal Lake and need immediate remediation strategies. The spatial WQI, asserts the high pollution levels of water quality at the Central Site Nigeen, Outlet Sites of Habak and Outlet Site of Hazratbal, also indicating soaring annual trends of spatial lake water deterioration. The spatial annual average development of overall WQI puts the status of the Dal Lake in the “Very Poor” category of water quality. The calculated temporal WQI, identifies Summer as the season which suffers most from the lake water pollution, having the highest WQI among all seasons, and also reflects the generally increasing annual trends of seasonal lake water deterioration. The average seasonal/temporal overall WQI of Dal Lake again puts the status of Dal Lake in the “Very Poor” category of water quality. Overall, this study may contribute towards the advancement of knowledge and development of conservation strategies for the Dal Lake.