Spatial and temporal variation of total suspended sediment concentration in Chilika lagoon using MODIS/ terra data

Abstract

This study investigates the use of Moderate Resolution Imaging Spectroradiometer (MODIS) visible band (band 1: 645 nm) surface reflectance for monitoring temporal and spatial variation of Total Suspended Sediment (TSS) concentration in Chilika Lagoon. Three algorithms were developed by using three different trend lines: Polynomial, Exponential and Linear to establish the relationship between in-situ TSS concentration and extracted surface reflectance value in band 1 (Rrs at 645 nm) from MODIS product. A significant relationship (R2=0.91; n=54; p<0.001) was established between in-situ TSS and MODIS band 1 surface reflectance (Rrs at 645 nm) using polynomial model. However, the other two models, exponential and linear were resulted in low R2 values (R2 =0.77 & R2 =0.73 respectively). Polynomial model resulted in least Root Mean Square Error (RMSE) value (RMSE=2.64 mg/L) and linear model in largest RMSE value (10.46 mg/L). Hence, band 1 polynomial model was implemented in the software, Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Data Analysis System (SeaDAS), to show the spatial variation of TSS concentration in Chilika Lake.