Real-time monitoring of deep-seated gravitational slope deformation in the Taiwan mountain belt

The deep-seated gravitational slope deformation (DGSD) on mountain areas is widespread and overexploitation has increased the frequency of natural disasters such as landslides, rockslides, and debris flows. In Taiwan, the observation and the analysis of the deep-seated landslides suggest that these are mainly controlled by tectonic structures, which play a dominant role in the deformation of massif slopes. Considerable enhancement for morphometric interpretation can be obtained by means of the integration with Airborne Light Detection And Ranging (LiDAR) technology. On the other hand, surface displacements ranging from a few millimeters to several centimeters can be easily measured by continuous Global Positioning System (GPS). Our study analyzes the characteristics of deep-seated gravitational slope deformation using a multi-technique approach by integrating data from the photogrammetry, LiDAR, GPS, rain gauges and field observations. A continuous GPS site, TENC, located along the southern cross-island highway, Taiwan, shows a huge displacement of about 240 mm during the Morakot typhoon in 2009. .