基于经验频率点据的暴雨公式参数研究

Research on the Parameters of Rainstorm Formula Based on Empirical Frequency Points

研究暴雨公式参数可为小流域设计洪水计算、山洪灾害防治和城镇排涝提供科学依据,对城镇规划和流域生态环境建设具有重要的意义。以陕西省18个主要气象站1984-2013年实测暴雨资料为依据,采用年最大值选样法选取了10、30、60、90和120 min 5个短历时的暴雨系列,分别依据经验频率点据的全系列和P<50%半系列以及P-Ⅲ型频率曲线拟合得到的全系列和P<50%半系列4个系列,应用麦夸尔特法求解了4参数暴雨公式的参数,分析了参数的精度,并研究了暴雨公式参数的地区性规律。结果表明:基于经验频率点据计算的暴雨公式精度比基于P-Ⅲ型曲线计算的公式精度高;基于P<50%半系列比基于全系列计算的暴雨公式精度高;基于经验频率点据P<50%半系列推求暴雨公式参数是最有效的途径;暴雨公式各参数与站点经纬度和高程在秦岭以北具有显著的线性相关性。

Studying the rainstorm formula can provide a scientific basis for the design flood calculation,flood control and town drainage in small watersheds,and is of great significance to urban planning and basin ecological environment construction. Based on the observed rainfall data of 18 major meteorological stations in Shaanxi Province from 1984 to 2013,five short-duration rainstorm series（ 10,30,60,90 and 120 min） were selected by the annual maximum sampling method,and then the four parameters rainstorm formulas were calculated with the Levenberg-Marquardt Method based on the whole series and the P 50% semi-series of the empirical frequency points and the whole series and the P50% semi-series fitted by the P？Ⅲcurve respectively. The accuracy of the parameters was analyzed and the regional laws of the rainstorm formula parameters of were studied. The results show that： The precision of rainstorm formula calculated based on empirical frequency points are higher than that of P？Ⅲ curve. The accuracy of rainstorm formula based on P50% semi-series is higher than that of the full series. It is the most effective way to calculate the rainstorm formula parameters based on P 50% semi-series of empirical frequency points. There is a significant linear correlation between the rainstorm formula parameters and the latitude,longitude and elevation of the station in the north of Qinling Mountains.