摘要
全球气候变暖导致山丘区极端降雨事件多发,降雨强度与量级不断突破区域历史极值,同时叠加区域脆弱环境和强人类活动影响,致使山洪形成及演进致灾成因复杂多变,由此加重了暴雨山洪引发的人员伤亡和财产损失。山洪灾害具有显著的自然和社会双重属性,其形成发展是山丘区环境孕灾承灾因子复合作用的结果。中国山丘区局地气候独特,地质地貌类型众多,溪河水系复杂,人类活动影响突出。大量重大山洪灾害事件表明,极端降雨诱发的山洪过程及致灾特征各异,给山洪灾害预报预警防御造成极大困扰,山洪灾害研究仍是当前重大自然灾害防控的重点和难点。长期以来,中国山洪灾害研究多偏重于雨水情时空变化规律,着重研究降雨影响的山洪洪水淹没特征,据此推算山洪灾害防治区的临界雨量与水位阈值,在山洪灾害防治实践应用中取得了较为显著的成效,山洪灾害事件导致的人员伤亡数总体显著下降。然而,受山丘区降雨特征、下垫面组成、溪河形态及人类活动等多因素影响,山洪洪水形成演进时挟带大量泥沙,从而表现为山洪水沙、山洪泥石流等物理过程,导致的局地冲毁、淤埋、淹没等致灾成因及阈值与山洪洪水致灾也存在本质差异,这也是近年来中国重大山洪灾害事件多发的主要原因。针对极端降雨诱发多类型山洪形成演进与强人类活动复合作用致灾防御难题,亟需利用气象学、水文学及河流动力学等多学科知识,采用现场调查、物理试验、数值模拟及理论分析相结合的方法,从传统单一的山洪洪水灾害研究扩展为全类型山洪灾害(山洪洪水灾害、山洪水沙灾害、山洪泥石流灾害)研究,开展全类型山洪引发的冲毁—淤埋—淹没等复合致灾研究,系统探究中国重灾省区重大山洪灾害事件的强降水时空演变规律,剖析极端降雨与强人类活动复合作用
Global warming has led to frequent extreme rainfall events in hilly areas,with rainfall intensity and magnitude constantly breaking regional historical records.Simultaneously,the fragile environment and intense human activities in these areas exacerbate the formation and evolution of flash floods,complicating the situation and increasing casualties and property losses.Flash flood disasters have significant natural and social 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 disaster 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 challenges of disaster prevention caused by extr
作者
王协康
WANG Xiekang(State Key Lab.of Hydraulics and Mountain River Eng.,Sichuan Univ.,Chengdu 610065,China)
出处
《工程科学与技术》
EI
CAS
CSCD
北大核心
2024年第4期1-9,共9页
Advanced Engineering Sciences
基金
国家自然科学基金重点项目(52239006)
国家自然科学基金委员会-中华人民共和国水利部-中国长江三峡集团有限公司长江水科学研究联合基金项目(U2340201)。
关键词
山区流域
极端降雨
强人类活动
山洪灾害
致灾成因
mountainous watershed
extreme rainfall
intense human activities
flash flood disasters
disaster causes
