An Efficient Approach to Modeling the Topographic Control of Surface Hydrology for Regional and Global Climate Modeling

作者：Marc Stieglitz, David H. Rind, J. S. Famiglietti, Cynthia E. Rosenzweig · 发表于：Journal of Climate · 年份：1997 · DOI：10.1175/1520-0442(1997)010<0118:aeatmt>2.0.co;2 · 被引用次数：264 · 研究领域：Hydrology and Watershed Management Studies、Soil and Unsaturated Flow、Soil Moisture and Remote Sensing

The current generation of land-surface models used in GCMs view the soil column as the fundamental hydrologic unit. While this may be effective in simulating such processes as the evolution of ground temperatures and the growth/ablation of a snowpack at the soil plot scale, it effectively ignores the role topography plays in the development of soil moisture heterogeneity and the subsequent impacts of this soil moisture heterogeneity on watershed evapotranspiration and the partitioning of surface fluxes. This view also ignores the role topography plays in the timing of discharge and the partitioning of discharge into surface runoff and baseflow. In this paper an approach to land-surface modeling is presented that allows us to view the watershed as the fundamental hydrologic unit. The analytic form of TOPMODEL equations are incorporated into the soil column framework and the resulting model is used to predict the saturated fraction of the watershed and baseflow in a consistent fashion. Soil moisture heterogeneity represented by saturated lowlands subsequently impacts the partitioning of surface fluxes, including evapotranspiration and runoff. The approach is computationally efficient, allows for a greatly improved simulation of the hydrologic cycle, and is easily coupled into the existing framework of the current generation of single column land-surface models. Because this approach uses the statistics of the topography rather than the details of the topography, it is compatibl...