寒区典型下垫面冻土水热过程对比研究(Ⅱ):水热传输  

Heat and Water Transfer Processes on the Typical Underlying Surfaces of Frozen Soil in Cold Regions(Ⅱ):Water and Heat Transfer

作　　者：阳勇[1] 陈仁升[1] 叶柏生[2] 宋耀选[1] 刘俊峰[1] 韩春坛[1] 刘章文[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所黑河上游生态-水文试验研究站/内陆河流域生态水文重点实验室,甘肃兰州730000 [2]中国科学院寒区旱区环境与工程研究所冰冻圈科学国家重点实验室,甘肃兰州730000

出　　处：《冰川冻土》2013年第6期1555-1563,共9页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(91025011;91125013;41222001)资助

摘　　要：依托中国科学院寒区旱区环境与工程研究所黑河上游生态-水文试验研究站葫芦沟试验小流域,选取4种典型寒区下垫面,利用CoupModel模型对试验点的土壤水热传输过程进行模拟计算.结果显示:冻土对土壤水热传输影响为开始冻结时,冻结作用导致土壤水向上运动,往冻结锋面集结;稳定冻结期,土壤水运动微弱,接近零通量;解冻期,土壤水运动与上下层水势有关.冻融阶段的土壤水相变会带来热量的急剧变化.不同下垫面土壤水迁移差异主要体现在冻结过程中土壤水向上运动期间.沼泽草甸试验点因土壤含水量较大,吸水过程较长且吸水量大于其他3个试验点;高山寒漠试验点因为土壤孔隙较大,成冰作用会使土壤中毛细孔增加,导致冻结过程中出现多次土壤水向上运动状态.植被覆盖、土壤性质、土壤含水量和冻土类型等是寒区不同下垫面冻土水热传输过程差异的主要原因.Four research sites covered with（1）alpine grassland（seasonally frozen soil）,（2）alpine meadow（seasonally frozen soil）,（3）alpine swampy meadow（permafrost）and（4）alpine clod desert（permafrost）were chosen to study the heat and water transfer processes of various underlying surfaces in cold regions.The simulations of transfer process of water and heat by CoupModel show that the water and heat transfer from deeper layer to the upper one when the soil is freezing.At the beginning,water in the deep layer moves upward to the freezing front and releases heat during the freezing process.While the soil layer is frozen,the water flow between the frozen layers become zero and is controlled by the vertical soil water potential during the thawing period.The soil heat flux increases sharply when water phase change takes place in soil with frozen/thaw process.The difference of soil water flow in various underlying surfaces presents when soil layer is freezing.In freezing time,the flow time and quantity of water transfer from deeper layer to upper one in alpine swampy meadow site is large because of largest soil water content;there are more water transfer processes in the alpine clod desert site,because the capillary action increases when the ice fill in the macro-pore.Vegetation,soil characteristics,soil liquid water content and frozen soil types are the influence factors of difference transfer of heat and water in different underlying surfaces.

关 键 词：寒区 冻土水文 CoupModel 水热传输 

分 类 号：P334[天文地球—水文科学]