Monitoring cases of rainfall-induced debris flows in China

Debris flows are considered one of the most hazardous types of mass movement. China has a long history of monitoring debris flows, which has enhanced the understanding of debris flows and the development of strategies for their prevention. This study reviewed case studies and outputs related to debris flow monitoring in China. The monitoring systems are set in seven catchments, with area between 2 and 40 km², covering various types of debris flows in different climate conditions. This review also introduced the definitions and classifications adopted for debris flows in China for comparison with those used in Western literatures. A comprehensive analysis was conducted of debris flow parameters, including the grain size distribution, density, Froude number, velocity–depth relationship, volume–peak discharge relationship, volume–drainage area relationship, and velocity and peak discharge calculation methods. Additionally, the rainfall intensity–duration thresholds were compared. Accurate identification of such information is fundamental for enhancing comprehension of debris flow characteristics, facilitating monitoring, and the implementation of early warning and alarm systems.