黑河高山草甸冻土带水热传输过程  

Heat and water transfer processes on alpine meadow frozen grounds of Heihe mountainous in Northwest China

作　　者：阳勇[1,2] 陈仁升[1,2] 吉喜斌[2] 卿文武[1,2] 刘俊峰[1,2] 韩春坛[1,2] 

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,甘肃兰州730000 [2]中国科学院生态水文与流域科学重点实验室,甘肃兰州730000

出　　处：《水科学进展》2010年第1期30-35,共6页Advances in Water Science

基　　金：国家自然科学基金资助项目(40771045;90702001-2;40401012);中国科学院知识创新工程重要方向性项目(KZCX2-YW-301-3);国家重点基础研究发展计划(973)资助项目(2007CB411506)~~

摘　　要：以黑河源区高山草甸冻土带的基本气象参数、植被参数和土壤水热性质参数为输入条件,利用CoupModel模型计算了试验点两个完整年度日尺度上的各种基本水热状况,计算结果较符合实测值(7层地温和土壤液态含水量平均R2分别为0.95和0.83)。利用模型输出的土壤热通量和土壤水迁移分析了试验点季节性冻土区的水热传输过程:在土壤层开始冻结期,下层土壤液态水向冻结锋面集结,集结期向上的地热通量急剧增加;在冻结期,土壤热传导主要与上下层的土壤温度有关,土壤水迁移基本处于零通量状态;在融化期,在融化锋面未出现液态水分集结现象,融化层土壤水热传输过程迅速改变并与非冻结土壤一致,向下的地热通量急剧增加。The hydrological process in frozen soil regions is very intensive to global warming. The coupled heat and mass transfer model for soil-plant-atmosphere system （CoupModel） is applied in the headwater region of the Heihe River, with an alpine meadow frozen ground landscape. The observed meteorological forcing and soil and vegetation properties are used in the CoupModel application for the period from September 10, 2005 to September 10, 2007. A 24-h time step is used in the model simulation. The results show that the simulated soil temperature and water content as well as frozen depth compare well with the observations. The coefficient of determination （R^2 ） of 7 soil layers is 0.95 for the mean soil temperature, and 0. 83 for the mean soil water content. An analysis is performed on the simulated heat and water transfer process from the deep soil layer to the upper one during the freezing seasons. At the beginning of the season, the water in the deep soil layer moves upward to the freezing front and releases heat during the freezing process. When the soil layer is frozen completely, there will be no vertical water exchanges between the soil layers, and the heat exchange process is controlled by the vertical soil temperature gradient. During the thawing perithe downward heat process becomes more active with the help of the increase of incoming shortwave radiation at ground surface. There will be no confinement of the melt water in the thawing front. Instead, the melt water will quickly dissolved in the soil. Eventually, the frozen soil heat and water transfer process vanishes and the unfrozen process returns.

关 键 词：黑河源区 高山草甸 冻土水文 水热传输 CoupModel模型 全球变暖 

分 类 号：P339[天文地球—水文科学]