Discussion of Issues About Sediment Deposition and Waterway Maintenance Dredging in the Fluctuating Backwater Area of Three Gorges Reservoir
Type:
Presented during:
WODCON XIX: "Dredging makes the World a better place" - 2010, Beijing, China
Authors:
Luo Hong
Abstract: The great changes in the staged hydrograph influences the fluctuating backwater area of the Three Gorges Reservoir, which changes the “deposition in flood seasons and erosion in dry seasons” under natural conditions and breaks the basic rules of equilibrium between scouring and deposition within a hydrological year. Accumulative deposition occurs, which hinders the navigation in some reaches in the drawdown period due to shoals. In addition to necessary structural measures, maintenance dredging is an important means to ensure a smooth waterway. We analyzed the waterway issues brought about by the sediment deposition of the reaches in the fluctuating backwater area after the impounding; preliminarily analysis was made regarding the time for shoals development which hinders navigation, based on the locations of reaches where navigation is hindered; we considered the influences of changes in the water stage on construction and put forward how to choose construction opportunities. We analyzed the characteristics of ordinary dredgers; put forward the types of dredgers suitable for the maintenance dredging of the waterway of the Three Gorges Reservoir; and make a proposal for comprehensive utilization of dredging sediment.
Keywords: test impounding, sediment deposition, construction opportunity, dredger, dredging sediment