Monitoring and early warning of debris-flow in an earthquake impacted area, Baishahe catchment, southwest China

Abstract

After 10 years of the Wenchuan earthquake of China, the post-seismic landslides are turning weak. However, the debris flows in earthquake-stricken area continue to be threat. In order to reduce the risk from debris flows in this region, we discuss the operation of an alert system, monitoring objectives, and early-warning policies. Three gullies in the Baishahe catchment, Dujiangyan, Southwest China were selected and rain-gauge, tilt-sensor, mud-meter and ground acoustic meter combined to a warning system in April, 2014. The data collected from these events shows changes in susceptibility levels and triggering rainfall complicating the application of a fixed rainfall threshold for any alert system.