Sediment Distribution and Treatment in the Inflow Water-Level-Fluctuating Zone of the Biliuhe Reservoir

Abstract

Most of the pollutants carried by runoff accumulate in the form of sediment, impacting the capacity and water quality of reservoirs. To study the sediment distribution in the water-level-fluctuating zone (WLFZ) of a reservoir in North China with a long drying period and to explore its treatment, the Biliuhe Reservoir in Dalian, Liaoning Province, China, was selected as the study area. The sediment thicknesses along the thalwegs of the three tributaries were surveyed, including a detailed survey on the sediment thickness and particle size in Dapu, the inflow bay of the main river. According to our findings, the sediment distribution along the thalwegs is similar to the delta sedimentation. The inflow WLFZ, especially the inflow bay, is the main gathering area for sediment. Furthermore, the variation in sediment thickness in the top-set region has river siltation characteristics, which are mainly affected by the scouring and deposition of floods during the dry period. From the convex bank to the inside of the bay in Dapu, the hydrodynamic force of the sediment gradually weakens, the thickness gradually increases, and the bay is the main sedimentary area of the suspended load. A method of sediment reuse for vegetation buffer platform construction is proposed. This method can reduce the amount of sediment entering downstream and enhance the ability to remove the pollution along the bank of the reservoir.