Integrated Space-Air-Ground Early Detection, Monitoring and Warning System for Potential Catastrophic Geohazards

XU Qiang , DONG Xiujun , LI Weile 中国地质灾害点多面广，且大多地处高位并被植被覆盖，传统的人工调查排查在一些地区进行地质灾害隐患识别已显得无能为力，这也是近年来绝大多数灾难性地质灾害事件都不在预案点范围内的主要原因。提出通过构建天-空-地一体化的“三查”体系进行重大地质灾害隐患的早期识别，再通过专业监测，在掌握地质灾害动态发展规律和特征的基础上，进行地质灾害的实时预警预报，以此破解“隐患点在哪里”“什么时候可能发生”这一地质灾害防治领域的难题和国家急切需求。“三查”体系首先通过光学遥感和合成孔径雷达干涉测量技术（interferometric synthetic aperture radar，InSAR）实现区域扫面性地质灾害隐患的普查，随后利用机载激光雷达测量技术（light laser detection and ranging，LiDAR）和无人机摄影测量实现高地质灾害风险区段和重大地质灾害隐患的详查，最后采用现场调查、地面与坡体内部监（探）测等手段，实现重大地质灾害隐患的复核确认和排除，即核查。监测预警则是通过InSAR和地面观测手段（如全球导航卫星系统、裂缝计等），在掌握滑坡崩塌的变形规律和阶段以及时间-空间变形特征的基础上，建立分级综合预警体系，并利用地质灾害实时监测预警系统，逐步实现地质灾害监测预警的实用化和业务化运行。 Abstract: In China, traditional methodology on early detection of natural terrain to landslides is challenging as zones most prone to slope failure are usually inaccessible due to high location and dense vegetation. This can lead to underestimation of potential landslide events to the degree of wrongly identifying unstable areas as stable. This paper provides a solution for these cases by proposing an integrated space-air-ground investigation system that allows for the early detection, real-time prediction, and warning of catastrophic geohazards. Firstly, high-resolution optical images and interferometric synthetic aperture radar (InSAR) data from satellites are employed to obtain a global panorama of a region, highlighting these problematic locations; yet results are detailed enough to provide reliable estimates of deformations at particular points along time spans of days and weeks. As consequence, it makes the compilation of long displacement time-histories feasible, contributing to the understanding of long-term landslide-driving phenomena in regions where it has been underestimated. This is called the general investigation. Then, detailed assessments can be done through the deve-lopment of unmanned aerial vehicles (UAV) for elaborating high-resolution relief maps and photogrammetric representations based on both visual images and light laser detection and ranging (LiDAR) data. The system finally allows for precise tagging of locations that warrant real-time site monitoring of displacements using global navigation satellite system (GNSS) and crack gauges, validating expecting behavior of these critical, but previously hidden hazardous locations. The overall approach makes it possible to establish a four-level comprehensive early warning system, which meets the urgent needs of the country and promotes a practical and operational application of such system in the field of geohazard prevention.