CONCEPTUAL CATCHMENT SCALE RAINFALL-RUNOFF MODELS AND AGCM LAND-SURFACE PARAMETERIZATION SCHEMES

The similarities and differences between conceptual rainfall-runoff mo dels developed by hydrologists and land-surface parameterisation schem es developed for incorporation into atmospheric general circulation mo dels (AGCMs) are explored. The simulations indicate that the key surfa ce water and energy quantities estimated by a typical rainfall-runoff model (MODHYDROLOG) and a typical land-surface scheme (BEST) for a wet tropical catchment and a temperate ephemeral catchment are reasonably similar. The results suggest that the parameterisations used in land- surface schemes can simulate runoff satisfactorily for wet areas but a re too simplified to model runoff adequately in ephemeral catchments. The simulations also suggest that the simple algorithms used in rainfa ll-runoff models can be adopted for climate change impact studies and for use with AGCMs.