Seasonal Retrieval of Suspended Sediment in the Pearl River Estuary Based on Measured Data

Suspended sediment is an important water quality parameter that plays an important role in regulating water and sediment dynamics in estuaries and shaping landform patterns. As one of China's important shipping channels, the sediment transport laws in the Pearl River Estuary (PRE) are very complex, which affects the water quality monitoring, pollutant transport, and offshore environmental and ecological protection of the PRE. This study takes the Pearl River Estuary as the study area, combines Landsat 8 images and measured data to construct suspended sediment inversion models in four seasons, and explores the seasonal patterns of suspended sediment concentration (SSC), to gain a deeper understanding of the transport mechanisms of suspended sediment in the PRE. The results show that: (1) From 2013 to 2021, there were significant seasonal differences in SSC. SSC was generally low during autumn and winter, and was higher during the dry season compared to the wet season. (2) At the interannual scale, SSC in the PRE exhibited a stable decrease. The suspended sediment is mainly concentrated at the estuary, and the spatial distribution pattern shows a distribution trend of higher on the west coast and lower on the east coast. (3) The suspended sediment in this region is influenced by various factors, such as upstream dam construction, seasonal rainfall changes, and land use changes. The findings of this study provide scientific insights for the sustainable development and ecological environment protection of the Pearl River Estuary, as well as suggestions for navigation safety and the security of infrastructure on both coasts.