摘要
青藏高原东缘地形地貌复杂,构造活动强烈,地质灾害频发,尤其是近年来的地震和人类工程活动增加了地质灾害强度,给国家重大工程、区域发展和公共安全等造成了巨大危害。本文首先概述了青藏高原东缘地质灾害成灾背景和发育特征,然后对比分析了不同区域地质灾害发育分布密度的差异性,重点剖析了地质灾害发育分布与影响因子之间的关系,探讨了影响因子对地质灾害发育分布的控制作用及其敏感性。研究表明,在青藏高原东缘,地形坡度、地形起伏度、斜坡坡型、年24 h最大降雨量、河网密度、到断裂距离、地震动峰值加速度、工程地质岩组和人类活动强度等9个因子具有较高的地质灾害敏感性,而斜坡坡向和年均降雨量具有较低的地质灾害敏感性。研究结果有利于加深对青藏高原东缘地质灾害成灾背景的认识,也可以为建立青藏高原东缘地质灾害评价指标体系提供重要参考。
In the eastern margin of Tibetan Plateau,the complicated geomorphology and strong tectonic activities bring frequent and destructive geohazards. Especially in recent years,earthquakes and human engineering activities have seriously increased geohazard intensity. So far,these unwelcome geohazards have caused great harms to national major projects,regional development,life and property and public safety. This paper firstly presents a general overview of the forming background and development characteristics of geohazards in the Eastern Margin of Tibetan Plateau. Then,the relationship between the geohazard distribution and causative factors was analyzed.Especially the control effect of causative factors on geohazard distribution was discussed through comparatively analyzing the differences of geohazard density of different regions. Finally,sensitivity of the causative factors of geohazards in the eastern margin of Tibetan Plateau was examined in depth. The study results show that nine factorshave higher geohazard sensitivity. They are terrain slope,terrain relief,slope shape,annual 24 h maximum precipitation,river density,distance to fault,ground peak acceleration,engineering geological group and human activity intensity. That is to say,they are more prone to geohazard occurrence. However,the slope aspect and annual precipitation have lower geohazard sensitivity and fewer control effect to geohazard occurrence. Moreover,the terrain slope of 25° - 40° and terrain relief of 120 - 160 m·km-2 have the highest geohazard sensitivity. The geohazard sensitivity of convex slope is higher than that of concave slope. The heavy rainfall with short duration（ 24 h maximum rainfall） has a higher control effect to geohazard occurrence. With the increase of river density,the geohazard intensity and density shows a corresponding increasing trend. With the decrease of distance to fault or the increase of ground peak acceleration,the geohazard intensity and density all shows an accompanying increasing trend. The study results can deepen the understanding of forming background of geohazards and also provide significant reference for establishing geohazard evaluation index system in the eastern margin of Tibetan Plateau.
作者
杨志华
张永双
郭长宝
姚鑫
YANG Zhihua;ZHANG Yongshuang;GUO Changbao;YAO Xin(Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081;Key Laboratory of Neotectonic Movement and Geohazard,Ministry of Land and Resources,Beijing 100081;ChinaInstituteofGeoEnvironmentMonitoring,Beijing10008)
出处
《工程地质学报》
CSCD
北大核心
2018年第3期673-683,共11页
Journal of Engineering Geology
基金
国家自然科学基金项目(41502313
41731287)
国家科技基础性工作专项课题(2011FY110100-2)
中国地质调查局地质调查项目(DD20160271
DD20179282)资助
关键词
青藏高原东缘
地质灾害
影响因子
敏感性分析
Easter nmargin of Tibetan Plateau
Geohazard
Causative factors
Sensitivity analysis
