极端降雨与强人类活动复合作用下山洪灾害研究构想和成果展望OA北大核心CSTPCD

Global warming has led to frequent extreme rainfall events in hilly areas,with rainfall intensity and magnitude constantly breaking re-gional historical records.Simultaneously,the fragile environment and intense human activities in these areas exacerbate the formation and evolu-tion of flash floods,complicating the situation and increasing casualties and property losses.Flash flood disasters have significant natural and so-cial attributes,resulting from the complex interaction of environmental factors in hilly areas.The local climate in the mountainous regions of our country is unique,characterized by diverse geological and geomorphic types,complex river systems,and prominent human activities.Numerous major flash flood events have demonstrated that the processes and characteristics of flash floods induced by extreme rainfall vary significantly,posing substantial challenges for prediction,warning,and defense.Research on flash floods remains a critical and difficult aspect of natural dis-aster prevention and control.Historically,flash flood research in China has focused on the spatiotemporal changes of rainfall and the inundation characteristics of water floods.This research has led to the calculation of critical rainfall/water level thresholds for flood disaster prevention and control,yielding significant practical results and reducing the overall number of casualties from water flood disasters.However,in mountainous areas,the formation and evolution of flash floods are influenced by multiple factors,including rainfall characteristics,surface composition,river morphology,and human activities.These floods often carry large amounts of sediment,manifesting as water floods,water-sediment floods,and debris floods.The causes and thresholds for local erosion,siltation,and inundation differ fundamentally between water-sediment and debris floods compared to water floods,contributing to the frequent occurrence of major flash flood disasters in China in recent years.To address the chal-lenges of disaster prevention caused by extreme rainfall and human activities,a combination of field investigation,physical experiments,numeric-al simulation,and theoretical analysis is adopted.Utilizing interdisciplinary knowledge from meteorology,hydrology,and river dynamics,re-search has expanded from the traditional study of water floods to include all types of flash floods,such as water-sediment and debris floods.This research aims to understand the composite disasters caused by these floods,including erosion,sedimentation,and inundation.We will systematic-ally explore the spatiotemporal evolution of heavy precipitation in major flash flood-prone provinces and regions of China,analyze the formation and evolution of multiple types of flash floods under extreme rainfall and strong human activities,and reveal the disaster mechanisms associated with meteorological,hydrological,and river responses.This involves establishing simulation methods for meteorological,hydrological,and sedi-ment dynamic processes,identifying the risks of flash flood erosion,deposition,and inundation in mountainous areas,and developing methods to identify prone areas for different types of flash floods.Additionally,we aim to construct a multi-index early warning and defense method for zon-ing and grading water floods,water-sediment floods,and debris floods.This study is expected to enhance the theoretical and technical research on flash flood disasters in China and improve strategies for their prevention and control.