滑坡二次灾害的三角面积比预警方法及其预警阈值确定  

Triangle area ratio warning method and warning threshold determination of secondary landslide disasters

作　　者：邵玮玺 肖先煊[1] SHAO Weixi;XIAO Xianxuan(State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]地质灾害防治与地质环境保护全国重点实验室(成都理工大学),成都610059

出　　处：《成都理工大学学报(自然科学版)》2025年第2期362-378,共17页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：地质灾害防治与地质环境保护国家重点实验室自主研究课题(SKLGP2021Z010)。

摘　　要：西南山区地质环境条件复杂,滑坡地质灾害频发,首次滑坡后的救援现场可能发生滑坡二次灾害,给应急抢险救援带来新的挑战。现有预警预报常出现延报、漏报及错报等问题,构建更可靠、更精准的预警方法是有效应急防灾减灾的重要出路。本文基于滑坡位移−时间曲线三阶段演化规律,建立了滑坡二次灾害三角面积比(Φ)预警方法。该方法依据各变形演化阶段曲线特征,提出了不同阶段的三角面积比计算公式并初步确定了其预警阈值:Φ<1,变形趋缓阶段;Φ=1,等速变形阶段;Φ>1,变形加剧阶段。在此基础上,以四川省普格县白水河滑坡二次灾害为例,在对地基合成孔径雷达(GBSAR)和小基线集干涉合成孔径雷达(SBAS-InSAR)位移−时间曲线提取基础上,研究了传统预警指标(包括变形速率V、累积加速度a、改进切线角α’)与预警阶段的对应关系,将利用三角面积比计算公式所得数值依照传统指标预警阈值划分标准进行了分析,变形加剧阶段可分为3个亚阶段,对应的三角面积比预警阈值为:①缓慢加剧阶段,1<Φ<1.2;②中等加剧阶段,1.2≤Φ<1.4;③快速加剧阶段,Φ≥1.4。研究认为,三角面积比预警阈值与传统预警阈值相结合可实现更为准确的预警预报。这为滑坡二次灾害监测预警预报提供新思路。In the southwest mountainous area of China,the geological environment conditions are complicated and geological disasters occur frequently.In these areas,it is difficult to prevent subsequent landslide catastrophes.Existing early warning and forecasts have frequent problems such as lags,missing alarms,and false alarms;thus,constructing a more reliable and accurate early warning method is an important way to prevent and alleviate emergencies effectively.This paper establishes a triangular area ratio(Φ)warning method for secondary landslide hazards based on the three-stage evolutionary behavior of landslide displacement-time curves.Based on the curve characteristics of each stage of deformation,we propose a formula for calculating the triangular area ratio at each stage.We preliminarily determine three warning thresholds:Φ<1,deformation slowing down stage;Φ=1,isochronous deformation stage;andΦ>1,deformation intensifying stage.On this basis,the secondary disaster of the Baishui River landslide in Puge county of Sichuan Province is taken as an example.Based on the extraction of GBSAR and SBAS-InSAR displacement-time curves,the correspondence between traditional warning indicators(including deformation rate,V,acceleration,a,and tangent angleα')and the proposed warning stages is investigated.The values obtained by using the triangular area ratio formula are divided in accordance with the criteria used to categorize the warning thresholds of traditional indicators.Based on this,the stage of intensified deformation can be divided into three substages,which correspond to the warning thresholds of the triangular area ratio:slow intensification stage,1<Φ<1.2;medium intensification stage,1.2≤Φ<1.4;and fast intensification stage,Φ≥1.4.The research presented here shows that the triangle area ratio warning threshold combined with the traditional warning threshold can achieve more accurate warning forecasts,providing a new way to monitor and forecast landslide disasters.

关 键 词：滑坡二次灾害 GBSAR SBAS-InSAR 预警指标 三角面积比 

分 类 号：P642.22[天文地球—工程地质学]