不同土壤物理属性空间分布对水文过程模拟的影响

Effects of Different Spatial Distributions of Soil Physical Properties on Hydrological Process Modeling

基于不同空间分辨率的土壤物理属性数据(土壤田间持水量、孔隙度和饱和水力传导度),运用WATLAC分布式水文模型模拟了西苕溪流域2005—2010年的水文过程。对比评价了土壤物理属性空间分布对地下水补给、土壤蒸发、径流量及其组分的影响。结果显示,利用不同空间分辨率土壤物理属性数据模拟的流量过程与实测值都匹配的很好,模拟精度相当,更详尽的土壤属性空间分布信息未能明显提高模型模拟的精度;而对于地下水补给量,高分辨率的土壤属性空间分布会使其模拟结果大幅减小,但对土壤蒸发量则影响较小,两种数据模拟的结果及其空间分布都很接近;同时,虽然土壤物理属性空间分布的分辨率对模拟的径流总量影响甚微,但对基流与地表径流的分割却产生了较大影响。

Different spatial resolutions of soil physical properties, including field capacity, soil porosity and saturated hydraulic conductivity, were used as input data for water flow model for lake catchment（WAT LAC） model to simulate the hydrological processes of the Xitiaoxi catchment from 2005 to 2010 and evaluate the effects of the spatial distribution of soil physical properties on groundwater recharge, soil evaporation, runoff generation and their components. Results show that the simulated stream flow hydrographs with dif ferent spatial resolutions of the soil physical properties reproduced the observed hydrographs well. There might be no significant increase in model accuracy as more precise information on the soil physical properties was used. The groundwater recharges simulated using the refined spatial information on soil physical proper ties were greatly lower than those using the conventional soil type data, but had a slight effect on soil evapo ration values. The two soil data cases showed a similar simulated result and spatial distribution. Although different spatial resolutions of the soil physical properties did not cause apparent difference in overall stream flow, their effect on the partition of surface and subsurface water flows was distinct.