First World Congress of International Consortium on Geo-disaster Reduction (1st ICGdR World Congress)

Under global climate change, mountain hazards such as landslides, debris flows, and flash floods have become increasingly frequent in China's mountainous regions. Although total casualties have declined significantly, sporadic mass-casualty events still occur, exposing persistent weaknesses in early warning dissemination and community emergency response. This study systematically reviews four disastrous events: the 2009 Typhoon Morakot-induced Xiaolin Village landslide (491 fatalities, Kaohsiung, southern Taiwan, China); the 2010 Zhouqu debris flow (1,765 dead or missing, Gansu); the 2020 Mianning flash flood and debris flow (22 dead or missing, Sichuan); and the 2022 Longcao Gully flash flood (7 dead, Sichuan). Four major human-induced factors are identified: (1) insufficient precision and spatial targeting of early warnings; (2) "last-mile" failure in early warning response; (3) weak public risk perception, with self-evacuation not yet an instinctive response; and (4) systematic underestimation of hazard chain risks. To address these challenges, a fine-scale forecasting system developed by the Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, dividing Sichuan into 14,000 small watersheds, has been providing dynamic nowcasts since 2022. Institutionally, a five-tier Public Participation Monitoring and Warning System (PPMWS) and a “wake-up and response” mechanism—integrating emergency broadcasting with a 3 km radius under “three-cut” conditions and a “30123” closed-loop protocol—create a fail-safe pathway from warning to time-bound community action. Persistent challenges include extreme weather unpredictability, complex hazard chains, unstable monitoring teams in remote communities, and managing transient populations. We propose an optimization framework combining scenario-based drills, “emergency first responder” training, household hazard awareness cards, and post-disaster psychological intervention. We argue that the deep integration of fine-grained early warning, the “wake-up and response” mechanism, and community response capacity is the critical pathway to reducing mass-casualty risks from catastrophic mountain disasters.

Catastrophic mountain disasters,Mass casualties,Last-mile failure,Community emergency response,Wake-up and response mechanism