Assessing water quality at Jakkur Lake: a comparative analysis of Landsat-8 OLI and Sentinel-2 Satellite Imagery

Abstract

Jakkur lake is one of the biggest lakes of Bangalore and is located on the northern side of the city. It derives its name from the name of the locality, Jakkur. The waterbody area is about 160 acres and length is about 1.5 km with several islands. Because of urbanization and increase in population, the catchment location is highly encroached. The amount of the stormwater achieving the lake has decreased making the streams dry. Remote sensing is a tool used for monitoring water bodies to present better spatial and temporal resolution. Remote sensing is also used for continuous monitoring and assessment of water bodies. Landsat-8 OLI and Sentinel-2 are recently launched multispectral sensors that have the potential to be used for the effective monitoring of the Jakkur Lake's water quality. Landsat-8 OLI and Sentinel-2 are similar in many approaches. Sentinel-2, however, has higher spatial resolution. The aim of this research was to find out if Sentinel-2 produces better results than Landsat-8 OLI in testing water quality parameters in the Jakkur lake. The parameters of interest were chlorophyll_a and turbidity. The results show that Sentinel-2 generates better results. For Sentinel-2, the R2 values for chlorophyll_a and turbidity were 0.975 and 0.845 respectively whilst for Landsat-8, the chlorophyll_a and turbidity R2 values were 0.911 and 0.747 respectively.