基于防洪排涝设计的鄂州市短历时暴雨雨型研究

Study on Short Duration Rainstorm Pattern Based on Flood Control and Drainage Design in Ezhou City

采用鄂州市国家气象观测站1980~2017年共38a的逐分钟降水资料,利用芝加哥雨型分析法推求鄂州市区重现期2a历时30、60、90、120、150、180 min以5 min为单位时段的设计短历时暴雨雨型,结果表明:利用芝加哥法推求鄂州市区各降水历设计暴雨雨型基本呈单峰形,短历时降水样本中单峰型所占比例最大,雨峰位于整场降水过程的前、中部;暴雨雨型雨峰位置超前于整场降水过程的1/2分位,各历时的降水强度随着重现期的延长而增大;利用芝加哥法推求的鄂州市暴雨雨型具有“单峰型、来得快、强度大、长尾巴”的特点。因此当短历时暴雨发生时,鄂州市水利、水文、住建、防洪等相关应在第一时间做好排水排捞准备,防止降水强度过大导致城市内涝灾害。

Using the minute-by-minute rainfall data of 38 years from 1980 to 2017 at Ezhou National Meteor-ological Observation Station, and the Chicago rain pattern analysis method, the design short-duration rainstorm pattern for Ezhou urban area with a return period of 2 years of 30, 60, 90, 120, 150, 180 min and a unit of 5 min was obtained. The results indicate that based on Chicago method, the design rainstorm pattern of Ezhou urban area is basically unimodal, the unimodal type accounted for the largest proportion in the short duration precipitation samples, the rain peak is located in the front and middle of the whole precipitation process;the location of the rainstorm peak was half of the whole precipitation process;and the precipitation intensity of each duration increased with the extension of the return period. The heavy rain pattern of Ezhou city is characterized by its “unimodal type, quick coming, stronger, long duration” by using Chicago method. So when a short duration rainstorm occurs, Ezhou water conservancy, hydrology, housing, flood control and so on should be ready for drainage and flood discharge in the first time to prevent urban waterlogging disaster caused by excessive rainfall intensity.