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受地形起伏影响,山区流域的水分和能量通量时空分布差异很大.利用水文模型VIC(variable infiltration capacity)对黑河上游流域的水文和能量时空分布进行了模拟,并通过观测对模拟结果进行了验证.结果表明:VIC模型能够较合理地模拟研究区径流过程,对净辐射的计算也较准确,模拟得到的部分水分通量和能量通量(感热、潜热和土壤热通量)在趋势上较一致,但在数量上存在偏差.积雪过程对研究区的水文和能量循环有重要影响,VIC模型对积雪的模拟偏差较大,导致了每年4月左右的模拟径流偏低,也没有模拟出积雪融化导致的土壤含水量上升;同时,积雪模拟的不准确也明显影响到能量通量的模拟.在研究区,土壤水分变化受土壤冻融影响明显,VIC模型对气温较高、不发生冻融过程的7-9月土壤水分变化模拟较好,但是在其他月份,对积雪及表层土壤消融导致的土壤水分迅速增加和土壤冻结导致的土壤水分迅速减少两个过程的模拟比较差;VIC模型能够给出水分和能量各通量的时空分布,较好地揭示研究流域各个通量的空间异质性及相互影响.
Influenced by the relief of the terrain, the spatial and temporal distribution of water and energy flux varies greatly in mountainous watershed.Using hydrologic model VIC (variable infiltration capacity) to simulate the spatial and temporal distribution of hydrology and energy in the upper reaches of the Heihe River basin, and through the observation of the simulation results The results show that the VIC model can simulate the runoff in the study area more reasonably and calculate the net radiation more accurately. Some of the water fluxes and energy fluxes (sensible heat, latent heat and soil heat flux) But there are some deviations in quantity.The process of snow accumulation has an important influence on the hydrological and energy cycling in the study area and the VIC model has a large deviation in the simulation of snow cover which leads to the low simulated runoff around April each year At the same time, inaccuracy of snow simulation obviously affected the simulation of energy flux.In the study area, the variation of soil moisture was significantly affected by soil freezing and thawing, while the VIC model was more sensitive to the air temperature Soil water change during July-September without high temperature and high temperature without freezing and thawing process was better, but in other months, soil moisture caused by snow cover and surface soil ablation increased rapidly Soil moisture in soil freezing due to rapid reduction in the simulation of both processes is relatively poor; VIC model can give time and space for each flux of energy and water distribution, to better reveal the spatial flux of each river basin study heterogeneity and interaction.