Studies On The Evaluation Of Reservoir Sedimentation Management

Sedimentation causes a range of impacts on reservoir by reducing reservoir storage.It is also a key problem for the study of reservoir sustainable management. An impactevaluation index system and model of sedimentation on reservoir and an evaluationmodel for reservoir sediment desilting were studied from the view of management andeconomy using AHP method and dynamic economic analysis. This dissertation is ofsignificance to reveal impacts of sedimentation on reservoir, and can provide referencesfor scientific restoration of reservoir storage.The impact evaluation index system of sedimentation on reservoir was developedbased on the analysis of impact of sedimentation on reservoir. The impact evaluationmodel of sedimentation on reservoir was established based on the AHP method. Theimpact evaluation model was tested in the Sanmenxia Reservoir, the XiaolangdiReservoir, the Naodehai Reservoir, the Guanting Reservoir and the DanjiangkouReservoir. The evaluation results can effectively reflect the impact degree ofsedimentation on these reservoirs, and indicate a good consistency with the actualreality, which shows that the impact evaluation model of sedimentation on reservoir canbe accepted to quantitatively evaluate the impact of sedimentation on reservoir.The Gould-Dincer approach was adopted to calculate water supply benefit, andreservoir power generation benefit calculation method was derived. The former sets upthe relationship of water supply with active storage, water supply reliability andcharacteristics of annual water inflow, the latter sets up the relationship of powergeneration with active storage, power generation reliability and characteristics of annualwater inflow. The Frequency method was adopted to develop flood control benefitcalculation method, which sets up the relationship of flood control benefit with floodstorage and characteristics of annual flood inflow. According to the reservoir benefitcalculation methods, the benefit of certain storage can be determined.Combined with sediment trap efficiency calculation and sediment desiltingcapacity calculation, the evaluation model for reservoir sediment desilting wasdeveloped using the economic optimization method based on the concept of “life cycle”management. The evaluation model consists of sediment trap efficiency calculation module, sediment desilting capacity calculation module, reservoir benefit calculationmodule and economic optimization module, which can not only consider the feasibilityof sediment desilting technique, but also can consider its economy. The life-timeaggregate net present values of different sediment desilting strategies are calculated andcompared by the evaluation model to determine the global economic optimal sedimentdesilting strategy. This evaluation model can be used as a useful reference to effectivemanagement of reservoir sedimentation.Besides,5typical reservoirs are evaluated using the evaluation model to determinethe optimal desilting process. The global economic optimal strategy of the SanmenxiaReservoir, the Xiaolangdi Reservoir and the Naodehai Reservoir is “storing the clearand releasing the muddy”. The global economic optimal strategy of the GuantingReservoir and the Danjiangkou Reservoir is “dredging”. The simulation results indicatea good consistency with the actual reality, which shows that the evaluation model forreservoir sediment desilting can be accepted to determine the global economic optimalsediment desilting strategy of reservoir.