Analysis Of Yuyang's Urbanization To The Rainfall&runoff

As one of the key development cities in the western development strategy,Yulin city is rich in resources and convenient transportation,with obvious geographical and developmental advantages.With the development of urban construction,due to the great changes in water and soil resources,a series of urban water circulation and water environment problems have been caused.Yuyang area urbanization level is based on the high area as the study area,analysis of nearly 20 years of urbanization,simulation study area,the influence of urbanization on the regional precipitation and runoff.The results of the study can provide a basis for urban flood prevention and disaster reduction and sustainable use of water resources,and provide scientific reference and basis for sustainable development of cities.The urbanization of Yuyang from 1990 to 2010 in the area of space urbanization.Using ENVI 5.1 software toYuyang district 1990,2000,2010 of the remote sensing image data extraction in six different land use types in a class,use the three periods of the change of land use type area reflects the development trend of the city.Set up the transfer matrix of land use change of Yuyang area,based on the transfer of land use change,especially the urban construction land to explain the space urbanization of Yuyang area,Yuyang district urban construction land expansion is 20 years more than 5.6 times,and Yuyang city index from 0.01045 to 0.05918.Use at the same time horizontal contrast and different period with different stop longitudinal comparative analysis method to analyze the Yuyang district space is the influence of urbanization on the regional precipitation,selection of rainfall time series is 1980 ~ 1980.Raised the rain coefficient method to calculate the coefficient and the results show that the period of the year raised rain in flood season raised the rain coefficients is greater than 1,and rain in flood season raised coefficient is greater than the same period of coefficient of rights in the rain.Mann-Kendall trend test results show that the Yuyang district of the city,suburban represent station 1980 ~ 2010 annual precipitation,annual flood season(from may to September)all showed increasing trend of precipitation increasing trend compared with suburb of city on behalf of the standing representative standing is more obvious.Using SCS model to simulate the different stages of urbanization between1990~2010 of annual runoff,and verify model in the adaptability and precision of the results in the study area.Analysis of high low CN value changes of the regional area under different conditions.From the simulation results of the runoff and runoff coefficient can be concluded that the land use ways,rainfall,the soil condition is different,annual runoff and the annual runoff coefficient are not the same.In AMC? rainfall frequency of 50%,In 1990,the runoff was 88.22 mm,the runoff coefficient was 0.25,in 2010,the runoff was 122.73 mm,and the runoff coefficient was 0.32,compared to 1990 runoff and runoffcoefficients have increased.In the early soil moisture conditions for the averagefrequency of rainfall in 2010 was 90%(dry year)and 10%(wet year)of annualrunoff from 64.13 mm to 180.16 mm,the runoff coefficient from0.25 to 0.4.