Spatiotemporal change in the surface temperature of Himalayan lake and its inter-relation with water quality and growth in aquatic vegetation

Abstract

Lake surface temperature (LST) monitoring is important as it plays a vital role in understanding the functioning of lakes and significantly shapes water ecological environments. A geospatial analysis was carried out to observe changes in LST for Wular lake during 1992 to 2017 using Landsat thermal data. This study revealed a warming trend in LST with increase in 1.82 °C for the period (1992–2017). It was perceived that LST significantly influences the water quality parameters and revealed a statistically significant relationship with R2 > 0.5 with a significance value (p) < .001 for most of the parameters. Ground validation of satellite-derived LST was done with in situ measurement having R2 and standard error of estimate equal to 0.71 and 0.77, respectively. Furthermore, Pearson’s correlation indicated towards a significantly positive relationship between normalized difference vegetation index and LST is an indicative of growth of aquatic vegetation in lake bed over the years.