基于“三查”体系的丹巴县滑坡隐患早期识别与监测

Early Detection and Monitoring of Potential Landslides in Danba County Based on the Space-Air-Ground Investigation System

针对高位隐蔽性滑坡隐患传统地面调查手段难以识别的问题,笔者所在团队提出了天-空-地协同的滑坡隐患识别与监测“三查”体系,并已在全国范围进行工程化应用,取得了较好的成效,但相关工作的学术报道较少。以滑坡灾害频发的大渡河流域丹巴县段为研究区,开展基于“三查”体系的滑坡隐患识别与监测具体实践。首先利用干涉图堆叠技术(stacking-interferometric synthetic aperture radar,Stacking-InSAR)和小基线集InSAR(small baseline subsets-InSAR,SBAS-InSAR)两种InSAR技术结合高分辨率光学遥感实现整个实验区活动滑坡隐患的广域普查,并对比分析Stacking-InSAR和SBAS-InSAR的识别结果;随后利用机载激光雷达测量技术和无人机航空摄影测量技术对丹巴县城周边高风险区段滑坡隐患进行详查,进一步通过现场调查实现重大滑坡隐患的核查,最后利用SBAS-InSAR技术对典型滑坡隐患形变进行监测分析。协同利用天-空-地观测手段在研究区共探测到滑坡隐患41处,主要为大型古老滑坡堆积体在长期重力作用、河流冲刷和人类工程活动等因素扰动下产生的局部复活,大部分滑坡隐患形变演化趋势与季节性降雨有较好的相关性。

Objectives:In view of the problem that it is difficult to identify the high hidden landslides by traditional ground investigation methods,the author's team have proposed the space-air-ground investigation system of landslide detection and monitoring.It has been applied nationwide with good results.However,there are few academic reports about it.In the study area of Danba County,where landslide disasters are frequent.Therefore,the detection and monitoring of potential landslides based on the space-air-ground investigation system was carried out.Methods:First,stacking-interferometric synthetic aperture radar(Stacking-InSAR)and small baseline subsets-InSAR(SBAS-InSAR)were combined with high-resolution optical remote sensing to achieve a wide-area census of active landslides in the whole study area,and the results of Stacking-InSAR and SBAS-InSAR were compared and analyzed.Second,light detection and ranging(LiDAR)technology and unmanned aerial vehicle aerial photography technology were used to conduct a detailed investigation of landslides in high-risk areas around Danba County,and further verification of major landslides through on-site investigation.Finally,SBAS-InSAR technology was used to monitor and analyze the deformation of typical landslides.Results:41 active landslides were detected in the study area by using the space-air-ground investigation system.They are mainly local resurgence of large ancient landslide accumulations under long-term gravity,river scouring and human engineering activities,etc.Most of the landslide deformations have a good correlation with rainfall.Conclusions:In the process of identifying landslides by using the space-air-ground investigation system,it is necessary to give full play to the advantages of each technical means.