长白山天池及邻区次生火山灾害类型、分布及其与火山地质的关系

Types and distribution of secondary volcanic hazards and their relationship with volcanic geology in Changbaishan-Tianchi and its adjacent areas

基于对长白山天池及邻区火山地质和次生火山灾害的编图结果,从岩性、断裂、地形地貌和水系等方面,分析火山喷出物的地质特征与这些火山物质所导致的次生火山灾害之间的相关性。研究表明,崩塌发生在柱状节理发育的硬质岩中,多期火山喷发以及伴生的地震活动剥蚀掏空坚硬岩层间的松散堆积体,使岩体失稳发生崩塌,局部陡崖地貌在地震影响下亦会发生崩塌灾害。软质岩和松散堆积体受流水侵蚀,河谷下切,河流两岸斜坡前缘形成开阔的滑动空间,火山地震引起山体变形,斜坡岩体结构遭到破坏发生滑坡灾害。火山先期喷出的碎屑物和崩塌滑坡产生的碎石是火山泥石流的重要物质来源,火山喷发或强地震引发的洪水灾害以及地形地貌对火山泥石流的形成、搬运和分布范围起关键性作用。

Based on the mapping results of volcanic geology and secondary volcanic hazards in Changbaishan-Tianchi and its adjacent areas,from the aspects of lithology,fracture,landform,geomorphology and water system,the correlation between the geological characteristics of volcanic products and the secondary volcanic hazards caused by these volcanic products is analyzed.The research shows that the rock collapses occur in the hard rock with columnar joints,as multiple volcanic eruptions and associated seismic activities denudate the loose accumulation between hard rock layers,and the rock mass loses stability and collapse.Steep slope landforms also collapseunder earthquakes.The soft rocks and loose accumulation of sediment are eroded away by water and cut down by the valley,forming open sliding space in the front edge of the slope on both sides of the river,and the volcano earthquakes induce mountain deformation,which damages the slope rock mass structure and results in landslides.Fragments from early volcanic eruption and debris generated by landslides are important material sources of volcanic debris flow,while flood disasters caused by volcanic eruptions or strong earthquakes,together with landform and geomorphology,play a key role in the formation,transportation and distribution of volcanic debris flows.