Estimating the suspended sediment concentration from TM/ Landsat-5 images for the Araguaia River - Brazil

摘要

In this study, 68 images from TM/Landsat-5 sensor were used to estimate Suspended Sediment Concentration (SSC) along of the Araguaia River, Brazil. These were combined with in-situ SSC, hydrosedimentometric station (categorical variable), and remote sensing reflectance. Top-of-Atmosphere (ToA) and surface reflectance data were evaluated. Multiple regression models with ToA reflectance using VNIR bands, band ratios, SWIR band 5 as input and station as categorical variable were more accurate with adjusted coefficient of determination (adjusted R-2) = 0.87 and normalized root mean square error (NRMSE) = 10.09% compared to the models with surface reflectance with adjusted R-2 = 0.60 and NRMSE = 15.43%. Results confirm the potential for estimation of SSC from TM/Landsat-5 historical series data between 1984 and 2012, for which in-situ database is rare. Based on this empirical model, future studies may provide better analysis of spatiotemporal variations of sediment transport along the Araguaia River with the SSC temporal series reconstitution.