摘要
科学合理地确定降雨诱发滑坡的预警阈值是区域防灾减灾的关键。以降雨型滑坡灾害高发的武陵山区为例,选取湖南慈利县1987—2011年逐年的历史滑坡灾害及降雨数据进行统计研究。首先,利用SPSS软件分析降雨与滑坡事件的相关性,发现该地区降雨型滑坡灾害主要受前3 d累积降雨量影响,且前期降雨有效系数仅为0.6;进而基于经验阈值分析模型,建立该地区分级预警的宏观平均有效降雨强度-降雨持续天数(I-D)降雨阈值曲线,并通过已知降雨滑坡事件进行空间验证;最后,考虑区内降雨型滑坡规模、滑体厚度及坡度的差异,分类建立了不同地质条件特性的I-D阈值曲线,发现临界降雨量阈值与滑坡规模及厚度呈显著正相关关系,而滑坡坡度则存在明显的最易发区间(25°~35°),此时临界降雨量阈值最小。研究结果可为武陵山区及相关地区降雨型滑坡的预测预报提供依据和借鉴。
The key to hazard control and reduction for rainfall-triggered landslide is to identify the warning threshold scientifically.With Wuling mountain area as an example,historical landslide data and rainfall data from 1987 to 2011 were analyzed statistically using SPSS to reveal the relevance between rainfall and landslide event.Rainfall-triggered landslide in this region was mainly affected by the accumulated rainfall in the first three days of rainfall,and the effective coefficient of early-stage rainfall was only 0.6.Subsequently,based on the empirical threshold analysis model,the macroscopic I-D(intensity-duration)rainfall threshold curve for staged early-warning was established and verified through known rainfall landslide events.In view of the differences in scale,thickness,and slope gradient of landslides in the region,the I-D threshold curves corresponding to different geological conditions were built.Results unveiled that the rainfall threshold was evidently positively correlated with the scale and thickness of landslide,whereas slope gradient had an apparent susceptible interval(25°to 35°)where rainfall threshold reached the minimum.The conclusion offers reference for the forecast of rainfall landslide in Wuling mountain area and related areas.
作者
林巍
李远耀
徐勇
连志鹏
曹颖
盛逸凡
LIN Wei;LI Yuan-yao;XU Yong;LIAN Zhi-peng;CAO Ying;SHENG Yi-fan(Geological Survey Research Institute,China University of Geosciences(Wuhan),Wuhan 430074,China;Wuhan Geological Survey Center,China Geological Survey,Wuhan 430205,China;Faculty of Engineering,China University of Geosciences(Wuhan),Wuhan 430074,China)
出处
《长江科学院院报》
CSCD
北大核心
2020年第2期48-54,共7页
Journal of Changjiang River Scientific Research Institute
基金
中国地质调查局地质调查项目(DD20160275)
国家自然科学基金项目(41702330)。
关键词
降雨型滑坡
分级预警
临界降雨量阈值
I-D阈值曲线
武陵山区
rainfall-triggered landslide
staged early-warning
critical rainfall threshold
Intensity-Duration threshold curve
Wuling mountain area
作者简介
林巍(1995-),男,浙江丽水人,硕士研究生,主要从事工程地质方面的研究。E-mail:lwcug2013@163.com;通信作者:李远耀(1978-),男,湖北宜昌人,副教授,博士,主要从事环境地质及地质灾害的教学与研究工作。E-mail:liyuanyao2004@163.com。
