青藏高原坡面尺度冻融循环与水热条件空间分布

发布时间：2018-04-02 18:17

本文选题：坡面尺度　切入点：冻融循环　出处：《科学通报》2015年07期

【摘要】：冻土的广泛分布使得青藏高原地表冻融循环与水热条件成为地球科学系统研究的关键之一.高原复杂的下垫面条件导致了冻融循环与水热交换显著的空间非均一性,而坡面尺度是认识地表过程空间变化的基础.本文基于青藏高原地表冻融循环与水热交换空间非均一性研究成果的回顾,利用安多地区近期的观测、模拟成果揭示了该领域的最新进展:首先评价了探地雷达在冻融循环与土壤水热空间变化研究的适用性;其次利用多元手段,显示了冻融循环与土壤水分坡面尺度的空间非均一性.另外利用冻土水热模型的敏感性试验发现:地表升温背景下,冻融过程与土壤水分在不同时期、不同深度、不同坡面的响应均有所不同,升温引起两个坡面冻结周期和速率变化明显.而且升温幅度越大,土壤水分的响应越明显,表层土壤水分的相对变化更为剧烈;对坡面而言,北坡的响应更为显著.
[Abstract]:The widespread distribution of frozen soil makes the freeze-thaw cycle and hydrothermal conditions of the surface of the Qinghai-Xizang Plateau become one of the key points in the study of the Earth science system.The complex underlying surface conditions of the plateau lead to the significant spatial heterogeneity between freeze-thaw cycle and water and heat exchange, and the slope scale is the basis of understanding the spatial variation of the surface process.Based on the review of the research results of the surface freeze-thaw cycle and the spatial heterogeneity of water and heat exchange over the Qinghai-Tibet Plateau, recent observations in the Ando region are used in this paper.The simulation results reveal the latest progress in this field. Firstly, the applicability of GPR in the study of freeze-thaw cycle and soil hydrothermal spatial variation is evaluated.The spatial heterogeneity between freeze-thaw cycle and soil water slope scale is shown.In addition, by using the sensitivity test of frozen soil hydrothermal model, it is found that under the background of surface warming, the response of freezing and thawing process and soil moisture in different periods, different depths and different slopes are different.The freezing period and rate of the two slopes are obviously changed by heating.And the larger the temperature range, the more obvious the response of soil moisture, and the more severe the relative change of surface soil moisture, and the more obvious the response of north slope is to the slope.
【作者单位】：中国科学院青藏高原研究所;中国科学院青藏高原地球科学卓越创新中心;中国科学院寒区旱区环境与工程研究所;中国气象局国家气候中心;
【基金】：国家自然科学基金(41071042) 中国科学院战略性先导科技专项(XDB03030200) 中国科学院“百人计划”(KZCX2-YW-BR-22)资助
【分类号】：P642.14

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