The Study On Flood Season Staging And Seasonal Design Flood Of Linhuaigang Flood Control Project

On the basis of runheji hydrological analysis research station measured rainfall and runoff data,on the basis of taking full consideration of the flood process fuzzy and random properties,make use of the combination of the qualitative analysis and the quantitative analysis.The most representative analysis method in the qualitative analysis method is the meteorological cause analysis method,it divides the study area flood season by the cause analysis method.the quantitative analysis method is divided into statistical analysis method and cluster analysis method;using the representative mathematical statistics method in the statistical analysis method to divide the flood season of the study area;respectively using the fuzzy season analysis method,set pair analysis method,fractal analysis method and Fisher optimal segmentation method in the cluster analysis method.By analyzing the advantages and disadvantages of each staging method,the staging results obtained by the Fisher optimal segmentation method are selected as the staging results of the study area.Finally,the flooding period of Linhuaigang flood control project is: the pre-flood season for the May 1 ~ June 10,the main flood season for the June 11 ~ August 10,the post-flood-season for the August 11 to September 30.Based on the results of the flood season staging,by summarizing the advantages and disadvantages of several sampling methods,the stall maximum sampling method is selected to study the staged design flood of Linhuaigang flood control project.For sampling methods,cross-sampling is used,in the original set of the beginning and end of the date extend forward and backward for 5 days.After the generalization of the flood frequency,on the basis of unreducing the annual flood control standard,this paper adopts the annual maximum sampling method for the main flood season,flood control standards is the annual flood control standards,the pre-flood-season and the post-flood-season using the maximum sampling stage,flood control standards is 3 times of the main flood season flood control standard(annual flood control standard).According to the collected flood data,the samples of each stage flood are obtained,the obtained flood index samples were fitted with Pearson type ? frequency curve fitting,The design flood index of each stage is calculated,and the current design flood method and the method used in this paper are compared with the original design flood index value.The method is used to analyze the design flood index value is closer to the original design flood index value,which can reflect the seasonal variation of the flood and meet the requirements of the annual flood control standard.