Surface water quality monitoring in large rivers with MODIS data

In this study, we propose to assess the use of MODIS images to monitor interannual variation of sediment flow by comparing surface reflectance data and field measurements of suspended sediment (SS) concentration collected every 10 days in surface waters of different locations of the Amazon River in Brazil. These data come from the HYBAM measurement network that measures the hydrology and geochemistry of the main rivers of the Amazon basin. In particular, we assess the effect of river width by analyzing different locations corresponding to river widths going from 500 meters to several kilometers. Several MODIS products are considered that include 250-meter and 500-meter resolution images and 8-day composites from Terra and Aqua on-board MODIS sensors. We show that the SS concentration can be monitored accurately over different hydrological cycles.