勉县暴雨强度公式推求及研究

发布时间：2018-08-25 15:29

【摘要】：近年来城市内涝给人们的生活、生产带来不利影响,甚至威胁到城市的发展和安全。暴雨强度公式是城市雨水、防涝工程建设的重要依据,因此编制与实际降雨特性相一致的暴雨强度公式是保障城市健康发展的重要前提。随着气候不断改变和城镇化的快速推进,城市的降雨规律已发生变化,故一些上世纪80年代编制的暴雨强度公式已不能很好的服务于当地的雨水工程建设;加之,我国大部分中小城镇没有运用当地的降雨资料编制暴雨强度公式,实际工程中通常借鉴邻近地区的暴雨强度公式,这使得当地所建设的雨水工程的安全性与经济性有待商榷。勉县没有当地的暴雨强度公式,故编制反映勉县降雨特征的暴雨强度公式是十分有必要的。本文基于勉县1996~2015年的原始降雨资料,运用年最大值法选取样本,建立降雨统计样本;首先选用三种理论分布模型对原始降雨资料进行频率拟合分析,获得不同分布模型下相应的i~t~P表,然后依次运用最小二乘法、麦夸尔特法、高斯牛顿法求解暴雨强度公式中的各未知参数;最后对符合规范要求的各公式的误差及其对应理论值与实测值之间的差率进行比较,最终确定出勉县暴雨强度公式。基于建立的降雨统计样本,运用3种理论模型对实测降雨资料进行频率拟合分析,得到的3组i~t~P表,分析结果误差可得:拟合效果最好的是耿贝尔模型,其次是皮尔逊Ⅲ型模型,最差的是指数模型。依据3组i~t~P表,分别运用上述3种求参方法获得9组暴雨强度公式,比较其误差可得:在同一分布模型下,麦夸尔特法求参误差最小,最小二乘法求参误差最大;在同一求参方法下,拟合效果最佳的是耿贝尔分布模型,其次是指数分布模型,效果最差的是皮尔逊Ⅲ型,这与频率调整结果有差异。因此,应对各分布模型均运用不同方法进行求参,通过最终的误差比较来确定出拟合效果最佳的理论频率分布模型。首先初选出5组符合规范要求的公式,其次计算各公式对应的理论值,通过理论值与降雨实测值差率的分析比较,确定出勉县暴雨强度公式为(?)和(?)。结合勉县城市规模,2~20年的暴雨强度公式通常应用于城镇雨水工程;2~100年的公式应用于城镇内涝防治工程。最终的勉县暴雨强度公式不适用于城镇水利防洪工程。
[Abstract]:In recent years, urban waterlogging has brought adverse effects to people's life and production, and even threatened the development and safety of cities. The formula of rainstorm intensity is an important basis for the construction of urban Rain Water and waterlogging prevention engineering. Therefore, it is an important prerequisite for ensuring the healthy development of the city to compile the formula of rainstorm intensity consistent with the actual rainfall characteristics. With the continuous change of climate and the rapid development of urbanization, the urban rainfall law has changed. Therefore, some of the rainstorm intensity formulas compiled in the 1980s can no longer serve the construction of the local Rain Water project. Most small and medium-sized towns in China do not use local rainfall data to compile the formula of rainstorm intensity. In practical engineering, the formula of rainstorm intensity in neighboring areas is usually used for reference, which makes the safety and economy of Rain Water project constructed in the local area open to question. There is no local formula of rainstorm intensity in Mian county, so it is necessary to compile the formula of rainstorm intensity to reflect the characteristics of rainfall in Mian county. Based on the original rainfall data from 1996 to 2015 in Mian County, the annual maximum value method is used to select the sample and establish the rainfall statistical sample. Firstly, three kinds of theoretical distribution models are used to analyze the frequency of the original rainfall data. The corresponding i~t~P tables under different distribution models are obtained, and then the least square method, McQualte method and Gao Si Newton method are used to solve the unknown parameters in the torrential rain intensity formula. Finally, the error of each formula and the difference rate between the corresponding theoretical value and the measured value are compared, and finally the formula of rainstorm intensity in Mian county is determined. Based on the established rainfall statistical samples, three kinds of theoretical models are used to analyze the frequency fitting of the measured rainfall data. The error of the three groups of i~t~P tables can be obtained: the Geng Bell model is the best fitting result. Followed by Pearson III model, the worst is the exponential model. According to the three sets of i~t~P tables, nine groups of torrential rain intensity formulas were obtained by using the above three methods, and the errors were compared: under the same distribution model, the minimum parameter error was obtained by McQuarrit method and the maximum error was obtained by least square method; Under the same parameter calculation method, the best fitting effect is Geng Bell distribution model, followed by exponential distribution model, and the worst one is Pearson 鈪，

本文编号：2203326