Remote sensing of suspended sediment concentrations of large rivers using multi-temporal MODIS images: an example in the Middle and Lower Yangtze River, China

摘要

Conventional measurements of suspended sediment concentration (SSC) are expensive, especially for large river systems. This study aims to examine the potential of estimating SSC of large rivers using high temporal resolution Terra Moderate Resolution Imaging Spectroradiometer (MODIS) data. In contrast to a small number of the samples used by previous studies on remote sensing of SSC, a large number of samples (n = 153) obtained on 63 dates at five sites across the entire Middle and Lower Yangtze River were employed to investigate the relationship between SSC and the water reflectance of MODIS images. The water reflectance difference between Bands 2 and 5 provided a relatively accurate SSC estimate after atmospheric correction, with 25% mean absolute relative error and 29.7% relative root mean square error. The errors were lower for larger SSC values. Thus, there is a potential that the Terra MODIS could be employed to estimate SSC frequently for large turbid river systems.