摘要
受“4·25”尼泊尔Ms8.1级地震影响,中尼边境山区发生了大量滑坡灾害,严重威胁人民生命安全及边疆经济建设。本文利用多时相遥感影像对震区滑坡进行了解译,引入关联维数探究了同震滑坡的空间分形特征,并结合二元Logistic模型和区域背景因素分析其形成原因。结果表明:(1)本次地震诱发的1431处滑坡大多为新生滑坡体,以浅层中小型为主,在高地震烈度区和公路两侧较为发育。受低角度逆冲断层影响,滑坡全部位于上盘,沿地震烈度圈长轴方向呈面状分布。(2)不同地震烈度区内的滑坡具有不同的分形特征,滑坡关联维数随着地震烈度等级的增大而增加,滑坡在空间上由聚集分布逐渐转变为均匀分布。(3)不同地震烈度区内的因子权重大小不同,其中距断层带距离因子对滑坡的影响最小,用该因子描述低角度逆冲断层地震同震滑坡存在一定的局限性,而坡度是对滑坡影响最大的因子。(4)在Ⅸ度地震烈度区内,各因素对滑坡的作用程度差异较小,滑坡的发生受到多因素共同控制,因此滑坡呈现相对均匀的分布特征;反之,在Ⅵ度地震烈度区内,滑坡的发生主要受到单一因素控制,所以呈现相对聚集的分布特征。本研究可为探讨同震滑坡的空间分布规律、同震滑坡的分形特征以及震后灾害管理等提供资料参考。
A large number of landslides have occurred in the mountainous areas along the border between China and Nepal,which were induced by the“4.25”Nepal Ms8.1 earthquake.These landslides led to heavy casualties and damaged the economic infrastructure of the border areas.Multi-temporal remote sensing images were used to interpret and investigate the landslides in the seismic area.A correlation fractal dimension was introduced to explore the spatial fractal characteristics of the co-seismic landslides.Moreover,the causes of these characteristics were analyzed by combining the binary logistic model and regional background factors.The results showed that most of the 1431 co-seismic landslides were neogenic landslides.They were mainly small and medium shallow landslides,and they were relatively developed on both sides of the highway and high seismic intensity areas.Under the influence of the low-angle thrust fault,all the landslides were located on the upper plate and distributed along the long axis of seismic intensity circle with a plane shape.The correlation fractal dimension increased with increases in seismic intensity,and the spatial distribution of the landslides changed gradually from aggregation to uniformity.The weights of factors were found to differ for areas with different seismic intensity.The distance from the fault had the least influence and had notable limitations regarding describing the landslides induced by low-angle thrust fault earthquakes.However,the slope had the greatest influence on the landslides.In theⅨseismic intensity area,the difference of each factor on the landslides was small,and the landslides in this area were affected by many factors,then they presented a relatively uniform characteristic.In contrast,in theⅥseismic intensity area,the landslides were mainly affected by a single factor,and it presented a relatively aggregated characteristic.The study can provide references for the spatial distribution of co-seismic landslides,the fractal characteristics of earthquake-induced landslides,and post-earthquake disaster management.
作者
蒋宁
苏凤环
徐京华
葛永刚
刘智
JIANG Ning;SU Fenghuan;XU Jinghua;GE Yonggang;LIU Zhi(Institute of Mountain Hazards and Environment, Chengdu 610041, China;Key Laboratory of Mountain Hazards and Surface Process, Chinese Academy of Sciences, Chengdu 610041, China;University of Chinese Academy of Sciences, Beijing 100049, China;Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China;Sichuan Institute of Geological Survey, Chengdu 610081, China)
出处
《山地学报》
CSCD
北大核心
2020年第5期699-709,共11页
Mountain Research
基金
第二次青藏高原综合科学考察研究资助项目(2019QZKK0902)
自然资源部中国地质调查局地质调查项目(DD20190545)
四川省科技计划项目(2019YFH0038)。
作者简介
蒋宁(1993-),男,河南开封人,博士研究生,主要研究方向:遥感技术与地理信息系统;通讯作者:苏凤环(1977-),女,山东阳谷人,博士,副研究员,主要研究方向:灾害遥感与山地灾害风险评估。
