【摘要】 为了寻求合理简化的流域地形指数水文模型TOPMODEL（Topographic Index model）用于大尺度的陆面模式，推导了土壤表层饱和导水率k₀、衰减因子f和地下水补给速率R空间都可变的扩展的TOPMODEL，并将f空间非均匀分布的TOPMODEL与陆面模式SSiB4耦合（SSiB4/GTOP）。通过耦合模型在f空间非均匀条件下进行实际流域的水文模拟，分析f空间非均匀对流域土壤湿度、蒸散发、地表径流、基流和总径流的影响。主要结论有：（1）k₀和R的空间变化并不改变经典TOPMODEL原有关系式，只要定义新的地形指数，k₀和R空间非均匀TOPMODEL与空间均匀的TOPMODEL并无区别；（2） f空间变化条件下由于局地的地下水埋深还与局地的f值有关，地形指数相同的区域具有水文相似性这一结论不再成立；（3）与f空间均匀的模拟结果相比较，f随海拔高度h i增加而线性减小使模拟的流域土壤湿度、地表径流和流域蒸散减小但使基流和总径流增加；（4） f空间非均匀对流域水文模拟结果有影响，但其影响明显小于流域地形因子的影响。更多还原

【Abstract】 To develop a reasonable and simplified TOPMODEL（Topographic Index model） that can be integrated into large-scale land surface models, the classic TOPMODEL is extended to spatially heterogeneous land surfaces, where saturated hydraulic conductivity at the ground surface k₀, water recharge rate to groundwater R, and decli ne factor f are all spatially heterogeneous. The extended TOPMODEL with a spatial variation of f is coupled with the land surface model SSiB4（SSiB4/GTOP）. In addition, numerical experiments with an assumed spatial variable pattern of f are conducted with the coupling model to evaluate the hydrological effects of the spatial variation of f. The effects of spatial heterogeneity on soil moisture, evapotranspiration, surface runoff, base flow, and total runoff are analyzed. The main conclusions are as follows:（1） The spatial variation of k₀ or R does not change the original relation of the classical TOPMODEL; as long as the new topographic indexes are defined, no differences exist between the spatially heterogeneous TOPMODEL and the spatially homogeneous TOPMODEL.（2） For heterogeneous f in space, because the local groundwater table depth is also related to the local value of f, the conclusion that the locations with the same topographic index are hydrologically similar is no longer valid.（3） Compared with the simulation results of the spatial homogeneity of f, the spatial variation of f, which linearly decreases with the increase in altitude, will reduce the soil moisture, surface runoff, and evapotranspiration of the simulated basins but increase the base flow and total runoff. 4) The spatial heterogeneity of faffects hydrological simulations; however, the topographic effects are more important than the influence of the spatial variation of f.更多还原