Résumé
In a continuing effort to test the behavior of Meteo France's land-surface scheme, Interaction Soil Biosphere Atmosphere (ISBA), under a wide range of hydrometeorological conditions, the scheme was applied to a small tropical high-mountain river basin of the Cordillera Real in Bolivia. The surface scheme simulates the key hydrological processes, such as evaporation, infiltration, surface runoff, and snow and soil ice freeze-thaw processes, which are essential for accurately simulating the hydrological behavior of the river basin in this type of location. The 12.5 km 2 nonglacierized subbasin has been divided into homogeneous surface units with irregular shapes, on the basis of their elevation and soil surface characteristics. The ISBA scheme was applied to each unit and the water fluxes were transferred from one unit to another using a system dynamics modeling approach. The method was applied step by step, improving its efficiency based on several hypotheses. This special application of the ISBA scheme, combining the high-mountain conditions and the tropical seasonality is discussed.