Study On Calculation Of Rainstorm Intensity Formula And Waterlogging Risk Assessment In Danjiangkou City

Level of urbanization in our country is higher and higher with the development of social economy, frequency of flood and waterlogging and its dangerous degree are becoming increasingly serious, and the sensitivity of the urban rainstorm and harmfulness of waterlogging on city increases.As the city’s most basic data, the existing rainstorm intensity formula of many cities no longer adapt to the changes with the development of urbanization and the drainage system design requirements.At the same time, the flood control and drainage system has failed to keep pace with the urban development, flood control and drainage plan lacks strong basis.Therefore, we must carry out system construction of urban drainage planning, so as to study the importance of urban rainstorm intensity formula and waterlogging risk assessment is obvious.This paper comprehensive summary based on the study of the rainstorm intensity establishment at home and abroad, using Danjiangkou City 33 years continuous rainfall data using the method ofannual maximum sampling,Taking the three most commonly used in heavy rain intensity model-Index, Gumbel and Pearson type Ⅲmatching model, and uses these two methods-Levenberg-Marguardt, and trust region to derive the parameters, and through the comparison of error analysis finalized Danjiangkou city rainstorm intensity formula Gumbel model trust region method is used to derive the formula,the final formula is (?)Through the analysis of the commonly used software for waterlogging risk assessment-Info Works, SWMM and MIKE, comprehensive comparing their advantages and disadvantages, finaly use Info Works software which is the fast and can determine 2d simulated computation for Danjiangkou City waterlogging risk assessment.Using the data of Danjiangkou City status of drainage, using urban waterlogging model of Info Works software we assessdrainage pipeline network capability, analysis found that 94.7% of the drainage pipe network to meet the standard of once a year, 67.8% of the pipe network to meet the standard of once every two years.we take Urban waterlogging risk assessment of Danjiangkou City at the same time, compare the historical waterlogging, found that the model can react the real waterlogging occurs, waterlogging risk area divided by the assessment results, high risk area covers area of 0.18 km~2, the middle risk area covers area of 0.40 km~2.In this paper, we get the Danjiangkou City rainstorm intensity formula and waterlogging risk assessment for the certain research, obtaine some valuable results, providethe helpof waterlogging control and drainage pipe network construction for the future.