Optimization of Controlled Water Level for Sediment Discharge of Xixiayuan Reservoir
In order to avoid the erosion and damage of retaining walls and hollowed out bedding during the period of sediment discharge at low water level of Xixiayuan Reservoir,and to control the sedimentation rate of the reservoir,it is necessary to scientifically propose reasonable controlled water levels for sediment discharge.Based on measured data,the sediment discharge laws of Xixiayuan Reservoir under different controlled water level were analyzed.The impact of three schemes of controlled water levels for sediment discharge of 128.5 m,130.0 m,and 131.0 m on reservoir erosion and sedimentation was calculated by using a one-dimensional water and sediment dynamics model.The results show that a)when the controlled water level of the reservoir is below 131.0 m,the sediment discharge ratio is basically above 60%;and when the controlled water level of the reservoir is above 131.0 m,the sediment discharge ratio is below 50%.b)Compared with the 130.0 m and 128.5 m schemes,the 131.0 m scheme only increases the sedimentation volume in the reservoir area by 2%~13%.c)At the end of the calculation period of 10 years,sedimentation forms of the 131.0 m,130.0 m and 128.5 m schemes are all below the designed equilibrium form of sedimentation,which are not harmful to the project.From the perspective of engineering safety,it is recommended to control the water level for sediment discharge in Xixiayuan Reservoir at 131.0 m.
controlled water level for sediment dischargeengineering safetycumulative sedimentation volumesedimentation formXixiayuan Reservoir