Analysis And Calculation Of Desigan Runoff Of Wangjiazui Reservoir Under Changing Environment

In today's society,a series of large-scale production activities of various land development and utilization and soil and water conservation projects have seriously affected the original underlying surface conditions of the basin.At the same time,climate change is gradually changing the river runoff.In the basins of climate change and human frequent water activities,runoff cannot be seen as a sequence from the same sample as a whole,but a non-uniform runoff sequence with jump mutations.Hydrological frequency calculations require hydrological event occurrence values to be obtained under the same conditions,subject to the same distribution.In the arid area of the loess,due to the influence of the dam and other projects,the measured daily flow series showed a trend of decreasing.The original hydrological statistical calculation method can no longer be applied to the existing conditions.This paper takes the design runoff calculation of the Wangjiazui Reservoir in the downstream of the Baizigou watershed in the province's silt dam system as an example.The Suihe River Suihua Hydrological Station is a data-free area.The main research area is the upper reaches of the Suihua Hydrological Station.A variety of methods were used to calculate the annual runoff of the design site under the changing environment,and the reliable water supply of the Wangjiazui Reservoir in Xunyi County was finally determined.This dessertation uses the sequential clustering method to optimally segment the annual runoff series from 1961 to 2015 in Suihua Hydrological Station,and uses Smirlov distribution consistency test,sliding F test method and sliding T test method.Methods The segmentation jump mutated points were verified.Finally,the double cumulative curve method was used to verify the annual runoff and surface rainfall inconsistency of the Suihua Hydrological Station from 1961 to 2015.It was determined that the underlying surface change is the only factor of river runoff changeing.On the basis of the search and check of the variation jump point of the non-consistent runoff sample sequence,the design guarantee rate annual runoff analysis and calculation are carried out.The use methods include:reduction coefficient method and full probability method,so as to calculate the annual runoff of the political station designThe non-uniform series frequency full probability calculation method for jump mutation is clear and clear,the operation is simple and the calculation result is reasonable;but the method has high requirements on the length of the sample series;the jump mutation point requirement is obvious,and it is necessary to calculate the upstream water volume.The area cannot be met and the scope of application is small.The design annual runoff is calculated by the reduction coefficient method and the full probability calculation method,and compared with the hydrological manual runoff modulus.It is recommended that the runoff reduction method be the reservoir design water supply schemeCombined with the tasks and requirements of the project,using the basic data of the Baizigou watershed topography and upstream and downstream rivers to obtain water,the reservoir design runoff is obtained through a certain hydrology and water conservancy calculation,and the designed water is provided at the dam site to determine the optimal reservoir size.