Water color from Sentinel-2 MSI data for monitoring large rivers: Yangtze and Danube

Rivers provide key ecosystem services that are inherently engineered and optimized to meet the strategic economic needs of countries around world. However, limited water quality records a full river continuum hindered understanding how systems response multiple stressors acting on them. This study highlights use Sentinel-2 Multi-Spectral Imager (MSI) data monitor changes in color two optically complex systems: Yangtze Danube using Forel-Ule Index (FUI). FUI divides into 21 classes from dark blue yellowish brown stemming historical scale has been promoted as useful indicator showing turbidity variations bodies. The results revealed contrasting patterns rivers both spatial seasonal scales. Spatially, River gradually increased upper reaches lower reaches, while declined which is possibly due sediment sink effect Iron Gate Dams. regional peaks valleys observed have also shown be related dams hydropower stations along Seasonally, can attributed climate seasonality, especially precipitation basin level. Moreover, land cover within was significant determinant color, higher levels vegetation were associated with values, whereas values system. furthers our knowledge MSI understand spatial-temporal capabilities an environment.