APPLICATION OF REMOTE SENSING AND GIS TO ASSESS THE ENVIRONMENTAL CHANGES in CHILIKA LAKE ECO SYSTEM

Abstract

ABSTRACT newlineThe Trophic State Index (TSI) of the Chilika Lake has been measured using secchi disk transparency (SDT) as well as the Landsat - 8 OLI and LISS-III bands. The water quality parameters such as dissolve oxygen (DO), pH, salinity, total suspended solid (TSS), turbidity, alkalinity, surface water temperature, ammonia, phosphate and nitrite of the Chilika Lake are collected and measured from different sectors. The result indicates spatiotemporal variations of water quality parameters during pre and post-monsoon season (2013-15). Different interpolation techniques have been evaluated and the best technique has been applied to create two dimensional water quality images of the Chilika Lake. An algorithm has been developed for estimation of TSI. The statistical analysis has been carried out by linear, exponential, logarithmic, power and polynomial modes. The coefficients of determinations are evaluated among all the modes and the best fit (R2 = 0.72) is observed in exponential mode.The analysis of LISS III and Landsat-8 OLI images indicate the lake water is in eutrophic condition since the year 2006 to 2015. The pre-monsoon period of 2006-15 the average TSI value is more as compared to post-monsoon period. This may be attributed to upwelling and wind driven re-suspension of bottom sediments. However, the average TSI values are comparatively less during the post-monsoon period of 2013 and 2015. This may be due to clear water and lesser influence of river water. The southern sector is always shows clear water in both the monsoon except 2015 pre-monsoon season due to upwelling and wind driven re-suspension of bottom sediments with high turbidity. The post-monsoon period SDT exhibits clear water always in southern sector and polluted water in northern sector. This is due to relatively deeper and the influx of river water is minimum in the southern sector compared to outer channel and northern sector which receives maximum amount of sediment during monsoon and post-monsoon season from the river drainage system and s