Sedimentation in the riparian zone of the Three Gorges Reservoir, China

摘要

Annual water levels in the Three Gorges Reservoir (TGR) fluctuate by approx. 30 m, which can influence the riparian zone. Such changes include soil stabilization or restoration, re-vegetation, landscape management and environmental sanitation. However, there is a lack of information on the rates, magnitude and variability of sedimentation processes in this riparian zone. A field monitoring programme was conducted along the middle reach of the TGR during 2007-2009. Fifteen monitoring transects were instrumented with columnar sediment traps and erosion pins. Mean sediment deposition rates were 5.8 cm year~(-1) at the 145-150 m level and 2.3 cm year~(-1) at the 150-175 m level. The mean sediment deposition rate was approx. 12 cm year~(-1) at tributary inlets and shoals and a maximum of 18 cm year~(-1) occurred at the 145-150 m level. Sedimentation processes in riparian areas along the TGR will likely have an impact on the ecology and long-term operation of the TGR.