Particle Size Distribution in the Yellow River Plume before and during Water and Sediment Diversion

Abstract:

Particle size distribution (PSD) is a critical measurement of the sediment fluxes and deposition that has not been adequately studied. Knowledge of the spatial and temporal variation of PSD can be used to evaluate the interaction between suspended sediment and biological and chemical components in coastal ocean. In this study the PSD were measured at more than 100 sites in the Yellow River Plume (YRP) before and after water and sediment diversion using a laser diffractometer (LISST-100X Type-B) in concert with multiple biogeochemical parameters collected during summer 2014. The measured PSD is fitted with Junge distribution to obtain the power-law slope and the differential number concentration for reference diameter. Results show that the total suspended particles ranged between 10 and 654 μL L^-1, median particle diameter (d0.5) ranged between 21 and 281μm, power-law fitted PSD slopes ranged from 3.2 to 4.4, reflecting the dominance of inorganic particles associated with the sediment discharged from the Yellow River. The spatial distribution of PSD also clearly displayed a dominant effect of riverine inputs. The depth-distribution of PSD slopes indicated that the deposition-resuspension process might be an important factor of the sediment dynamics. Our study provides valuable information on the distribution and transport of sediment discharged from the Yellow River in surrounding coastal water.