Abstract
The Wenchuan Earthquake took place in the upper reach catchment of the Min River. It resulted in large amounts of loose materials gathering in the river channel, leading to changes in the sediment transport system in this area. The Zipingpu Reservoir is the last and the largest reservoir located in the upper reach of the Min River. It is near the epicenter and receives sediment from upstream. This paper puts forward a study on the reservoir sedimentation and storage capacity of the Zipingpu Reservoir, employing a multi-beam echo-sounder system in December 2012. Then, the data were merged with digital line graphics and shuttle radar topography mission data in ArcGIS to build a digital elevation model and triangulate the irregular network of Zipingpu Reservoir. Via the analysis of the bathymetric data, the results show the following: (1) The main channels of the reservoir gradually aggrade to a flat bottom from the deep-cutting valley. Sedimentation forms a reach with a W-shaped longitudinal thalweg profile and an almost zero slope reach in the upstream section of the reservoir due to the natural barrier induced by a landslide; (2) The loss ratios of the wetted cross-section surface are higher than 10% in the upstream section of the reservoir and higher than 40% in the natural barrier area; (3) Comparing the surveyed area storage capacity of December 2012 with March 2008, the Zipingpu Reservoir has lost 15.28% of its capacity at the dead storage water level and 10.49% of its capacity at the flood limit water level.
Highlights
Dam construction breaks the sediment balance in a natural river, creating an impounded river reach [1]
We found that the terrain beneath the water surface was imaged well with detailed topographic features obtained by the multi-beam echo-sounder (MBES) as shown in Figure 5, which can show the reliability of the terrain
The results clearly demonstrate that the MBES method is suitable to provide a detailed map and visualization of a large reservoir
Summary
Dam construction breaks the sediment balance in a natural river, creating an impounded river reach [1]. As the water level rises, the flow speed decreases, and so does the sediment transport capacity [2,3,4,5]. The reservoir will gather sediment and lose capacity until a balance is once again achieved, normally after the sediment fills up the impoundment [6]. 0.5–1% of the global reservoir storage is lost each year, while the sedimentation rate varies between. The worldwide loss of storage caused by sedimentation each year is greater than the increased capacity from newly built reservoirs [8]. Continual sedimentation can no longer assure reservoir capacity, flood control, power generation, irrigation, and other benefits related to
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
