青藏高原热融湖横向扩张速率对湖下融区发展影响的数值模拟

发布时间：2018-05-14 12:22

本文选题：热融湖 + 横向扩张速率　；参考：《冰川冻土》2017年02期

【摘要】：热融湖是高纬度和高海拔富冰多年冻土区重要的自然景观。这些湖由于富冰多年冻土或地下冰的融化而形成,由于湖水向周边多年冻土传递热量而持续扩张。以青藏高原北麓河地区一个热融湖的信息和冻土监测资料为基础,运用柱坐标系下伴有相变的热传导模型模拟了以不同的横向扩张速率演化的热融湖湖下融区的发展过程。结果表明:在青藏高原多年冻土厚度为75 m的北麓河盆地,分别以横向扩张速率0.10 m·a~(-1)、0.15 m·a~(-1)、0.20 m·a~(-1)和0.25 m·a~(-1)演化的热融湖,在湖形成分别达760 a、703 a、671 a和652 a时,湖下形成贯通融区,相应的多年冻土从上向下融化的平均速率分别为8.22 cm·a~(-1),8.89 cm·a~(-1),9.31 cm·a~(-1)和9.74 cm·a~(-1)。热融湖的横向扩张速率对湖下的融区发展和土壤热状况有重要的影响,在现场调查资料的基础上选取正确的热融湖横向扩张速率是热融湖对多年冻土热状况作用数值模拟研究的必要前提。
[Abstract]:Hot thawing lake is an important natural landscape in high latitude and high altitude ice-rich permafrost region. These lakes are formed by the melting of ice rich permafrost or underground ice and continue to expand because of the heat transfer from lake water to the surrounding permafrost. Based on the information of a hot thawing lake and the monitoring data of permafrost in the northern part of Qinghai-Xizang Plateau, a thermal conduction model with phase transformation in cylindrical coordinate system is used to simulate the development process of the thawing area under the lake with different lateral spreading rates. The results show that in the North Luhe Basin with a thickness of 75 m permafrost in the Qinghai-Xizang Plateau, the thermal thawing lakes, which evolved at a transverse spreading rate of 0.10 m / a ~ (-1) and 0.25 m ~ (a) ~ (-1) of permafrost, respectively, formed a thawing zone under the lake at 760 a, 703 a, 671 a and 652 a, respectively, and the thawing zone was formed under the lake at a transverse spreading rate of 0.10 m / a ~ (-1) and 0.25 m / a ~ (-1), respectively. The average melting rates of permafrost from top to bottom are 8.22 cm / a ~ (-1) and 9.74 cm / a ~ (-1) respectively. The lateral expansion rate of the heat thawing lake has an important influence on the development of the melting area and the soil thermal condition under the lake. On the basis of the field investigation data, it is necessary to select the correct lateral expansion rate of thermal thawing lake for the numerical simulation of the effect of thermal thawing lake on permafrost.
【作者单位】：肇庆学院数学与统计学院;中国科学院西北生态环境资源研究院冻土工程国家重点实验室;
【基金】：国家自然科学基金项目(41271076) 广东省自然科学基金项目(2015A030313704)资助
【分类号】：P642.14;P901

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