基于特征参数的长历时降雨雨型研究

Research on Rainfall Pattern of Long Duration Rainfall Based on Characteristic Parameters

近年来极端降雨频发,从而引发城市内涝、山洪、泥石流等灾害。由于长历时降雨往往伴随着较大的降雨量,其致灾能力不可忽视。降雨雨型对降雨导致的灾害影响较大,开展长历时降雨雨型研究对防灾减灾工作具有重要意义。以四川省苍溪县降雨为例,依据苍溪站2013~2022年逐时降雨资料,采用综合雨峰位置系数和集中趋势度将33场长历时降雨划分为七种不同雨型,并确定了各典型雨型的时程分配。结果表明,该地区长历时降雨主要以峰值偏前或居中的集中型降雨为主,分散型及均匀型降雨发生的概率较小。不同雨型的雨量分配在降雨前期即存在明显差别,因此可结合气象数据,在整场降雨的中前期对雨型进行预测,为相关防护工作提供依据。

Extreme rainfall has been frequent in recent years,leading to disasters such as urban flooding,flash floods and mudslides.Since long duration rainfall is often accompanied with large rainfall amount,its disaster causing ability cannot be ignored.The rainfall pattern has a large impact on the disasters caused by rainfall,and it is of great significance to carry out the research on rainfall pattern of long duration rainfall for disaster prevention and mitigation.Cangxi county in Sichuan Province is taken as the study area.Based on the hourly rainfall data at the Cangxi station from 2013 to 2022,33 long duration rainfall events are classified into 7 different rainfall patterns by using the integrated rain peak location coefficients and the concentration trend indexes.And then the time-range distributions of each typical rainfall pattern are determined.The results show that the long duration rainfall in the region is mainly concentrated rainfall with peaks at the front or center,and the probability of scattered and uniform rainfall is small.The rainfall distribution of different rainfall types is obviously different in the early stage of the rainfall.So,it is possible to predict the rainfall types in the middle and early stages of the whole rainfall by combining the meteorological data,which can provide a scientific basis for the related protection work.