One-dimensional statistical dynamic representation of subgrid spatial variability of precipitation in the two-layer variable infiltration capacity model
One-dimensional statistical dynamic representation of subgrid spatial variability of precipitation in the two-layer variable infiltration capacity model
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DOI：
10.1029/96jd01448
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发表时间：
1996-09
影响因子：
--
通讯作者：
Xu Liang;D. Lettenmaier;E. Wood
中科院分区：
文献类型：
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作者：
Xu Liang;D. Lettenmaier;E. Wood
两层可变入渗能力（维克-2L）模型扩展到包括降水的次网格变率的表示，使用分析一维统计动态表示部分区域覆盖的降水。分析方法允许子网格尺度的降水对地表通量，径流量和土壤水分的空间变异性的影响被明确表示。用这种方法，空间集成表示的地表通量，径流，和土壤水分由于亚网格尺度的降水，渗透和植被覆盖的空间变异。使用一个详尽的像素为基础的方法，并通过应用均匀的降水覆盖面积所获得的结果进行比较。网格单元的降水覆盖率在估算地表通量、径流和土壤湿度方面起着主要作用。一般来说，降水覆盖区内降水的空间分布起着次要作用，部分原因是维克-2L代表了土壤性质的次网格空间变异性。虽然分析方法给出了基于像素的方法的良好近似，并且总体上上级均匀降水方法，但是差异并不大。
The two-layer variable infiltration capacity (VIC-2L) model is extended to incorporate a representation of subgrid variability in precipitation, using an analytical one-dimensional statistical dynamic representation for partial area coverage of precipitation. The analytical approach allows the effects of subgrid-scale spatial variability of precipitation on surface fluxes, runoff production, and soil moisture to be represented explicitly. With this method, spatially integrated representations of surface fluxes, runoff, and soil moisture due to subgrid-scale spatial variability in precipitation, infiltration, and vegetation cover are obtained. The results are compared with those obtained using an exhaustive pixel-based approach, and the results obtained by applying uniform precipitation over the precipitation-covered area. The precipitation coverage over a grid cell is shown to play a primary role in estimating the surface fluxes, runoff, and soil moisture. In general, the spatial distribution of precipitation within the precipitation-covered area plays a secondary role, in part because VIC-2L represents the subgrid spatial variability of soil properties. While the analytical approach gives good approximations to the pixel-based approach, and is superior to the uniform precipitation approach in general, the differences are not large.