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青藏高原多年冻土区由于自然环境变化和人为活动的影响,不少区域存在如热融滑塌、冻胀丘、融沉、冻胀等与冻土变化相关的冻融灾害。冻融灾害的存在与发展给冻土区环境与开发带来极大影响。在广泛现场调查和查阅相关资料的基础上,分析了各种灾害的形成机制以及冻融灾害的主要影响因素。结合地质灾害形成机理和多年冻土区工程建设的实际情况,确定了以岩土性质、活动层厚度、植被覆盖度、坡度、海拔、纬度为内因,年平均气温变化、人为活动为外因的评价模式。评价结果表明,整个青藏高原在现状条件下以中低风险性为主。中高风险区主要分布在年平均地温较高、人类活动强度较大的区域。
In the permafrost region of Qinghai-Tibet Plateau, due to the changes of natural environment and human activities, there are many regions such as thawing and thawing, freezing and thawing, melting and thawing, frost heave and so on. The existence and development of freeze-thaw disaster have a tremendous impact on the environment and development in permafrost regions. On the basis of extensive field investigation and access to related information, the formation mechanism of various disasters and the main influencing factors of freeze-thaw disaster are analyzed. Combined with the formation mechanism of geological disasters and the actual situation of the project construction in permafrost regions, the evaluation of external factors such as geotechnical properties, active layer thickness, vegetation coverage, slope, altitude and latitude as internal factors, annual mean temperature and human activities mode. The evaluation results show that the entire Qinghai-Tibet Plateau is characterized by low and medium risk under the current conditions. The high-risk areas are mainly distributed in areas with high annual average ground temperature and high intensity of human activities.