Hydrology and Earth System Sciences www.hydrol-earth-syst-sci.net 1027-5606 1607-7938 2 1 1998 10.5194/hess-2-51-1998 http://www.hydrol-earth-syst-sci.net/2/51/1998/ http://www.hydrol-earth-syst-sci.net/2/51/1998/hess-2-51-1998.html http://www.hydrol-earth-syst-sci.net/2/51/1998/hess-2-51-1998.pdf 51 64 0000-00-00 Spatial and temporal predictions of soil moisture patterns and evaporative losses using TOPMODEL and the GASFLUX model for an Alaskan catchment P. F. Quinn B. Ostendorf K. Beven J. Tenhunen Water Resource Systems Research Laboratory, Department of Civil Engineering, University of Newcastle Upon Tyne, NE1 7RU, UK. European Academy Balzona/Bozen, Department of Alpine Environment, Domplatz 3, I–39100, Bozen, Italy. Centre for Research on Environmental Systems, Lancaster University, Lancaster, LA1 4YQ, UK. Department of Plant Ecology, BITOK, University of Beyreuth, D–95440, Beyreuth, Germany. By using topographic indices as derived from a Digital Terrain Models (DTM), it is possible to represent the heterogeneity within a landscape. This heterogeneity can reflect both long term evolutionary patterns seen in a landscape and the short term forcing of flow dynamics during storm events. By spatial analysis, the linkage between the geomorphological- hydrological-plant physiological phenomena can be examined. In this study, a direct link will be established between the topographically-driven hydrological phenomena and the eco-physiological response. The topographic distribution function of TOPMODEL is used to control the spatial and temporal flux of the channel flow and water table. The plant physiological model GAS-FLUX is used to give a spatially and temporally dissaggregated species-sensitive estimate of evapotranspiration flux. Evapotranspiration is sensitive to the vegetation phonology, to tundra community physiology and to the temperature regime. A simple linking of TOPMODEL and the GAS-FLUX model is applied to a summer snow-free period to the Imnavait catchment, Alaska (2.2 km²). A species-sensitive evapotranspiration model proved to give the highest quality results when validated against flow observations. Predicted dynamics of variable source area and the component hydrological processes are illustrated.</p>