中国诱发滑坡的降水极端性特征及变化趋势  

Extreme Characteristics and Variation Trend of Rainfall-Induced Landslides in China

作　　者：徐辉 XU Hui(National Meteorological Center,Beijing 100081,China)

机构地区：[1]国家气象中心,北京100081

出　　处：《山地学报》2023年第4期545-553,共9页Mountain Research

基　　金：国家重点研发计划(2019YFC1510702)。

摘　　要：极端降水往往会造成滑坡灾害,但关于引发滑坡灾害的极端降水特征量化评估研究仍不足。本文基于近20年(2000—2019年)的中国地面观测站点降水数据和2014—2018年历史滑坡灾害个例数据,运用百分位数、标准化距平和Mann-Kendall方法分析诱发滑坡的极端降水特征,初步揭示了滑坡灾害与极端降水间的关系,探讨了近20年来中国范围内的极端降水与滑坡灾害的时空分布特征及变化趋势。结果表明:(1)诱发滑坡灾害的不同时间尺度降水绝大部分都存在极端性特征,导致滑坡灾害的发生一般是一年之中某个时间尺度内出现了极端性累积降水;(2)异常性降水是滑坡灾害的关键诱发因素,绝大部分滑坡灾害点的前期过程有效雨量均超出气候平均2σ以上,具有明显的降水异常性;(3)近20年以来中国遭遇极端日降水和过程降水事件的次数整体呈现增长趋势,而不同区域内的极端降水变化特征存在较大差异,除了黄淮、云南、华南东部的部分地区存在减少趋势以外,其他大部地区的极端日降水、极端过程有效降水事件发生频次均呈增多趋势。本研究成果揭示了诱发滑坡灾害的触发因素和极端降水事件的变化趋势,可为基于极端降水的滑坡预报预警提供科学依据。Extreme precipitation often causes landslides,but there was a lack of quantitative research on the extreme characteristics and variation trend of rainfall-induced landslides.In this study,it preliminarily revealed the relationship between landslide occurrences and extreme rainfall based on the observations at ground meteorological stations in China from 2000 to 2019 and the recorded rainfall-induced landslide events from 2014 to 2018.The extreme characteristics of rainfall-induced landslides in China were analyzed by percentile,standardized anomaly and Mann-Kendall methods,and then it concluded the distribution and variation trend of extreme precipitation in the past 20 years(2000-2019)as well as the corresponding landslides for the same period.We get the following results.(1)Most of the precipitation triggering landslides at different time scales had extreme characteristics.Landslides occurred generally on a certain time scale of a year with extreme cumulative precipitation.(2)Abnormal precipitation is the key inducing factor of disasters.The effective precedent rainfall at most of landslide sites exceeded the average of precipitation by more than 2σ,presenting apparent anomaly.(3)For the past 20 years,the number of extreme daily precipitation and process precipitation events in China had shown an obvious growth trend in general,but the change characteristics of extreme precipitation events also had relatively large discrepancy in different regions.In addition to Huanghuai,Yunnan,and parts of eastern South China had a decreasing trend,the frequency of extreme daily precipitation and extreme process effective precipitation events in most other areas showed an increasing trend.This trend of extreme precipitation had a good correspondence with the frequency of landslide disasters.Except for the decreasing trend in some areas of Huanghuai Plain,Yunnan,and eastern South China,the frequency of extreme daily precipitation and extreme process effective precipitation events had shown an increasing trend in most other ar

关 键 词：滑坡 降水极端性 前期有效雨量 百分位数 标准化距平 

分 类 号：P426.61[天文地球—大气科学及气象学]