Research On Loss Of Life Due To Dam-break Based On The Numerical Simulation

The flood caused by dam break will seriously affect the life of the people in the downstream areas.So the assessment of the loss of life due to dam break flood has become an important part of the flood risk management.The main contents of the assessments mainly include the hydrological information analysis of flooded area,the determination of population exposed to the flood,and the assessment of mortality of exposed population.In the existing research of hydrological information analysis,the numerical simulations of dam-break flood are mostly based on one-dimensional or two-dimensional model.In the existing research of the determination of exposed population,the study on the mechanism of the production process of loss of life is lacking.In the existing researches of the mortality of exposed population,Chinese assessments of loss of life due to dam break flood cannot be assessed using existing foreign mature mortality function analysis method,due to the different conditions of the country.Meanwhile,the loss of life has some characteristics including the large amount of influence parameters,the strong uncertainty and the obvious interaction between parameters.And the existing researches are in lack of the discussion on the influence of the parameters of the loss on the evaluation results.According to the above problem,on the basis of the summary of the existing research,this paper carries out the research of the assessment of loss of life due to dam break flood mainly from the following four aspects:(1)The dam-break flood disaster evaluation model based on fine terrain modeling and the modified RNG k-ε model coupled with the VOF method was established.Firstly,the fine terrain modeling combined with the equivalent roughness method was adopted to provide fine underlying surface information for dam break flood simulation.Secondly,the modified RNG k-ε model coupled with the VOF method,which has good performance in the aspect of anisotropic turbulence including analog strong cyclone,curved wall flow,and curved streamline flow,was employed.The dam-break flood disaster evaluation model will provide the reliable and pivotal hydrological information for the assessment of loss of life due to dam break flood.(2)The risk population exposure assessment model composed of the risk population assessment model,the risk population shelter model and temporary shelter safety criteria were established.The effect of the risk population evacuation behavior,the risk population shelter behavior and the shelter safety were synthetically taken into consideration to determine the final amount of exposed population in dam flood areas.The loss of life due to dam break flood assessment model could reflect the mechanism of the appearance of loss of life due to dam break flood better.(3)The exposed population vulnerability assessment model was established.Firstly,the historical data of domestic and international occurred dam break in literatures were summarized.Secondly,according to the flood characteristics,flood inundated area was divided.Lastly,by fitting historical data,the mortality function,suitable for China’s situation,of each flood areas of the loss of life due to dam break flood was established.The exposed population vulnerability assessment model was established by the above work to determine the possibility of death of the population exposed in the flood.(4)On the basis of the global sensitivity analysis method-extended fourier amplitude sensitivity test,the sensitivity analysis of parameters of the loss of life due to dam break flood assessment model was carried out.In conjunction with the parameters’ total sensitivity index and first-order sensitivity index,input parameters having great effect on the model output results was screened out,which could provide guidance for the applying of the loss of life due to dam break flood assessment model.