Applications of Thermal Images for Monitoring Surficial Temperature Changes of Naked Slope

Abstract

Global climate change causes increases in the torrential rainfall brought by typhoons and the monsoon in Taiwan. Torrential rain in turn causes landslides, debris flows, and the formation of earth dams. Most dams were formed in remote mountainous areas and are difficult to reach for safety evaluation at the beginning of their formation. A long distance and non-destructive testing methodology is necessary for evaluating the safety of landslide dams. This study used an infrared imager for monitoring naked slopes. The thermography can detect surficial radiation temperature changes in the slope to locate potential unstable areas for further monitoring. This study proposes radiation temperature change (T) per unit of time (Δt) as an index (T /Δt) for nondestructive monitoring. The index was used for monitoring and analysis of artificial earth dams constructed at Huishun farm in Nantou County. The results of the analysis show that the failure zone of the artificial dam exhibited the greatest change in the index and the potential failure mode could be predicted once the dam breached. The proposed model could be used for potential unstable slope monitoring.