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介绍了黑河源区野牛沟流域在试验点尺度和山坡尺度上所开展的冻土水文过程初步结果.冻土水文观测场建于最大冻结深度约为3.0 m的季节冻土区,近50 a来,该区降水量变化不大,器测蒸发量(20)和风速呈明显的降低趋势,而气温和地表温度则分别上升约1.0℃和1.7℃.研究区季节冻土冻结上限和下限深度均与地表温度呈二次多项式关系,这表明地表温度与冻结或融化区地温变化之间有一个滞后过程.在地表融化季节,季节冻土存在两层现象.当融化深度接近最大冻结深度时,存在向上和向下的双向融化现象,但自下而上融化速率较慢.2005年9月—2006年9月,具有较高代表性的3个山坡径流场均没有观测到产流量,结合蒸散发观测和野外调查,发现夏季高山草甸具有明显的地表径流拦蓄和水源涵养作用.COUP模型能够较好的连续演算试验场生长季节高山草甸-季节冻土-大气-维水热传输和耦合过程,但因其土壤完全冻结临界温度阀值设置偏高,影响了非生长季节的计算精度.
The preliminary results of the hydrological process of the frozen soil at the experimental scale and hillside scale in the Ye Niu Gou drainage area are introduced.The frozen ground hydrological observation field is built in the seasonally frozen soil region with the maximum frozen depth of about 3.0 m and nearly 50 years (20) and wind speed decreased obviously while the temperature and surface temperature increased by about 1.0 ℃ and 1.7 ℃ respectively.The freezing and freezing depths of the seasonal frost in the study area Which shows a quadratic polynomial relation with the surface temperature, which indicates that there is a lag between the surface temperature and the change of the ground temperature in the freezing or thawing zone.In the surface thawing season, there are two layers of seasonal frozen soil.When the thawing depth approaches the maximum freezing depth, There is a two-way melting phenomenon up and down, but the bottom-up melting rate is relatively slow. From September 2005 to September 2006, the runoff fields of three hillsides with high representativeness were not observed. The results showed that summer alpine meadow had obvious surface runoff interception and water conservation function.COUP model can better calculate the growth season of experimental field alpine meadows - seasonal frozen soil - atmosphere - dimensional water Transmission and coupling process, but because the soil completely frozen critical temperature threshold is set too high, affecting the accuracy of non-growing season.