Estimation of Trophic State Index of Chilika Lake using Landsat-8 OLI and LISS-III satellite data

Abstract

Trophic State Index (TSI) of the Chilika Lake has been estimated using secchi disk transparency (SDT) as well as satellite data. An algorithm was developed to estimate TSI using in-situ observed SDT and band ratio of Landsat-8 OLI in exponential mode (R2 = 0.72). Different interpolation methods have been applied and the best one was considered to prepare two dimensional water quality images of the lake. The in-situ and satellite observed, TSI value shows the northern sector is always in eutrophic to hypereutrophic condition. During pre-monsoon season of 2015 the southern sector shows lake water is eutrophic condition. The analysis of satellite image indicate the lake water is in eutrophic condition from the year 2006 to 2015. However, the average TSI values were comparatively less during post-monsoon season of 2013 and 2015.