Salinity Distribution and Sediment Flux in the Estuarine Xuanmen Reservoir

摘要

The salinity distribution in the water and sediment of the Xuanmen estuarine reservoir was investigated by a field survey. Additionally, a sediment flux model was built to predict the solute release from the sediment. The results indicate that the water in the reservoir is currently not suitable for drinking because of its high chloride concentration. The long water retention time is found to be responsible for the high electrical conductivity values in zone II of the reservoir. Our simulations show that the chloride release from the sediment will decrease slowly, nearly stabilizing, in the next 40 years, and the chloride released per stored water volume will be reduced from 5.0 to 2.9 mg/L. The high chloride concentration in the reservoir is probably caused by the extremely uneven distribution of water retention time in the reservoir, whereby the accumulated chloride cannot be effectively diluted by freshwater from the tributaries.