Research Of Storm And Flood Calculation In Small Ungauged Basins At Hilly Areas Of Shandong Province

Recently years, there are many flash floods happends in our courtry, and it has became a Constraint for the development and stability of the mountain area. However, the watersheds which happen flash floods easily are always located at these hilly areas where lack of hydrological data. And this situation promoted the difficulty of floods’ prediction. This paper is based on the flash floods prevention projects of Shandong province, aiming at gaining the rainfall data of hilly areas’ ungauged small watersheds and methods of calculating their floods. The main works are summarized as fallowing:(1)Overviewed the background of the research and its’ purpose and significance. Summarized the research status of related areas. Given out this paper’s technology roadmap.(2)Investigated whether is it feasible and suitable using the spatial interpolation methods into hilly areas. First, we overviewed the spatial variability of rainfall data and the factors which influences the rain at hilly areas, including elevation,slope and aspect. Summarized the methods of spatial interpolation. And did a research in Zhangqiu case, then from the result concluded that local polynomial method and the krig methods are much better and reasonable then others. After this, we using the two methods into short term rainfall and rainfall events’ interpolation and extension. The spatial results show that the method is feasible and the krig is better then correlation analysis method.(3)In order to find out the comprehensive features and realize the localization of rational formula, this paper did a research on parameter m’s regional complex. First,we did a overview of rational formula’s development and research status. In Shandong province,12 hydrological stations and 195 fields rain and floods profile case, we did the area comprehensive and single station comprehensive. Then we got the relationship about m and other parameters, and using them into peak flows’ calculation of Beifeng basin.(4) Storm and flood calculation in watershed short of data are mainly divided into three section, including rainfall, runoff and converge. This paper primarily discusses three methods of converge including HEC-HMS model, rational formula and experience formula, and uses them into mountainous small watersheds. In Beifeng basin and 4 small watersheds’ peak flow simulation case,we did the calculation. Through the results, HEC-HMS model is a much better method in small watersheds then other two; Rational formula is suitable at small watersheds, but there are larger error when calculating the big area basins.