青海省祁连山聚乎更矿区冻土特征及其生态地质功能作用研究

Research on Permafrost Characteristics and Eco-geological Function of Juhugen Mining Area,Qilian Mountains,Qinghai Province

聚乎更矿区是青藏高原多年冻土区重要的煤炭资源生产地。矿区多年冻土类型为亚稳定型,冻土厚度大,对环境变化的响应较敏感。观测数据显示,多年冻土内部温度场呈现相对“急剧”、“恒定”、“稳定”三个显著规律变化区段。矿区多年冻土受海拔和地形地貌控制,表现为西厚东薄。在区域气候变暖背景下,多年冻土的地温呈增加趋势,上限逐步下降,下限逐步抬升,多年冻土地温正向着退化的方向变化。冻土作为浅部地下水含隔水层的实质载体和支撑地表植被、湿地等生态环境的基础,同时兼具水源涵养、植被保护、碳库固碳、工程地质安全、成矿控矿等多重生态地质功能作用,对高原高寒地区生态系统的稳定和演化起重要作用。

Juhugen mining area is an important coal resource production area in the permafrost region of Qinghai-Tibet Plateau.The main type of permafrost in this mining area is substable,and the permafrost is thick and sensitive to environmental changes.The observation data for many years show that the internal temperature field of permafrost presents three significant regularities of relative“sharp”,“constant”and“stable”.Permafrost in the mining area is controlled by altitude and landform,which is thick in the West and thin in the East.Under the background of regional climate warming,the geothermal temperature of permafrost in this region is increasing.The upper limit is gradually decreasing,and the lower limit is gradually rising.The geothermal temperature of permafrost is changing towards the direction of degradation.As the substantial carrier of shallow groundwater containing water-repellent layer and the foundation of supporting surface vegetation,wetland and other ecological environment,permafrost has multiple ecological geological functions,such as an important component of underground hydrologic water-repellent layer,water conservation,vegetation protection,carbon sequestration,engineering geological safety,mineralization and ore control,etc.It plays a pivotal role in the stability and evolution of ecosystem in the plateau region.