Prof. Chien-Yuan Chen, Chinese Taipei
Department of Civil and Water Resources Engineering, National Chiayi university
Title: Slope Stability and Vegetation Monitoring by Using Infrared Thermal Imager
Abstract: Thermal imagers are characterized by noncontact and long-distance detection capabilities, rendering them suitable for landslide monitoring. A thermal imager can reveal changes in surface radiation temperatures and can be used for monitoring slope surface temperature changes. The purpose of the study was to understand the slope stability and vegetation changes by monitoring surface infrared temperature changes. The field large scale earth dam experimental test and landslide cases in a mudstone area in Taiwan were monitored for this study. Thermographs obtained by a handheld thermal imager from various times were analyzed for monitoring the surface temperature changes on slope faces. In addition, an unmanned-aerial-system (UAS) mounted thermal imager was used to capture digital orthophoto thermal images for setting up a three-dimensional monitoring net. These images indicated that wet soil had higher water content and exhibited a lower surficial infrared temperature change. Infrared temperature changes per unit time served as monitoring variables and were compared with isotherms for detecting potentially unstable areas. The results demonstrated that a potentially unstable area could be detected through the thermal images. Accordingly, landslide monitoring could be improved by thermal imagers.