Using Motion Sensor for Landslide Monitoring and Hazard Mitigation

Owing to tectonic collision, about 70% of Taiwan’s land are mountains and foothills. With several unfavourable conditions such as typhoons, strong rainfalls, and earthquakes, the landslide hazard is a critical issue in Taiwan. This issue is increasingly important because the use of hillsides for residence are growing in recent years. To address the issue and to protect its citizens, Taipei City Government initiated a pilot project to monitor landslide displacements in 2010. The project involves a selected hillside community with dip slope in Taipei City. The community had a major landslide in 1983.The monthly monitoring with non-automated devices is not helpful for residence to react to landslides. To help improve the situation, we use motion sensors to develop fully automated devices to infer displacements. We also used numerical analyses to help determine the best locations to install these devices. They were mounted to the ground surface to sense the tilt. The tilt converts to displacements by assuming slip surfaces. Small displacements were detected during a typhoon event in July of 2013.With the developed monitoring device, standard operation procedures were developed accordingly. Community residents has been educated how to react to unfavourable conditions. These conditions are defined by displacements exceeding certain thresholds.