Economic Loss Evaluation Of Dam Breach Based On Flood Evolution Simulation And Matter-element Partition

Once the dam breach,it will have a huge impact on the downstream area.Dam breach loss research is an important part of dam risk assessment and management.At present,some achievements have been made in the economic loss of reservoir dam breach,but there is a lack of specific analysis of the impact of disaster-causing factors on the loss rate with the change of distance,resulting in rough assessment results.Therefore,supported by the National Natural Science Foundation of China(51679222,51709239),this paper studies the dam-breach economic losses based on flood routing simulation and matter element zoning.The main work and results are as follows:(1)Simulation of dam-breaching flood routing.The form of dam breach is analyzed,the working conditions of dam breach are determined,and the flow process line of dam breach is deduced as the initial condition of dam breach flood evolution.Combined with the HEC-RAS two-dimensional model,the calculation principle and modeling steps are expounded in detail.Through the simulation of dam-breach flood,the water depth,velocity and other hydrological information of downstream areas are obtained,which provides the basis for the subsequent flood area division and loss rate determination.(2)Matter element model was used for flood risk zoning in submerged area.Three disaster-causing factors,namely,inundation depth,maximum flow velocity and flood arrival time,were used to characterize the flood disaster characteristics each region,and the inundation area was divided according to the relevant classification standards.The matter-element model is introduced to solve the incompatibility problem of dam-breach flood disaster-causing factors.The submerged area is divided into six levels:extremely dangerous area,dangerous area,heavy disaster area,moderate disaster area,light disaster area and safety area.(3)A dam-breach economic loss assessment model is constructed.Consider the different types of economic loss from dam failure,and analyze the factors that affect the rate of economic loss.Combined with flood risk zoning and general flood loss rate,the calculation method of economic loss rate in dam-breach submerged area is proposed.The direct economic loss and indirect economic loss of different property types are calculated to evaluate the economic loss of dam breach.(4)Engineering example simulation analysis.According to the simulation results of dam-breach flood of Qianping Reservoir,the level of submerged area was determined based on matter-element method.The water regime data and various economic layers are superimposed to determine the submerged area of various types of property;According to the level of submerged area and the submerged area of various types of property,the economic loss of dam breach is evaluated.The results can provide theoretical and technical support for the formulation of disaster prevention and mitigation plan for reservoir dams.