Seasonal distribution and driving forces of suspended particulate matter in the northern Yellow River Delta

The distribution and diffusion of suspended particulate matter (SPM) in coastal waters play an important role on ecological environment, coastal geomorphic evolution, aquaculture and coastal engineering. The northern Yellow River Delta is a strong coastal erosion area due to the diversion of Diaokou course. Revealing the variation characteristics and laws of SPM concentration in this area is the basis for maintaining the safety of protection projects. Using the well-validated model to retrieve the SPM concentration in the coastal waters, the cross validation results of Landsat-8 and Sentinel-2 satellite sensors show that the SPM concentrations retrieved by the two sensors have strong consistency, and the two kinds of satellite data can be used together. The seasonal variation of SPM concentration in the study area is obvious. The concentration of SPM is higher in spring and winter, and lower in summer. Autumn is the season when SPM concentration changes from low to high. In winter and spring, the wind and waves are large in this area. Under the combined action of waves and current, strong sediment resuspension occurs, which is the main source of SPM. The construction of spur dike group altered the spatial and temporal distribution of SPM to a certain extent.