Rainfall−runoff modelling of the Ouse basin, North Yorkshire: an application of a physically based distributed model

Abstract A physically based distributed rainfall-runoff model is applied to the basin of the River Ouse, North Yorkshire, with a catchment area of 3315 km2. The model includes a description of overland flow, subsurface flow, vertical water transfer in the soil, evapotranspiration, and channel flow in the river network. The finite-element schematization of the catchment provides a representation of the drainage network and the spatial pattern of topography, soils, and meteorological inputs. Most of the parameters of the model are determined on the basis of the topography and measured soil characteristics. Other parameters are calibrated using 15 min rainfall and flow data for six flood events and daily rainfall and runoff data for 1986. Temporal disaggregation based on the average variability method of Pilgrim et al. (Civ. Eng. Trans. Inst. Eng. Aust., CE11: 9–14, 1969) is used to generate hourly estimates of rainfall from daily measurements. Model simulations are compared with daily flow measurements for the years 1987–1990. Results show that the model can simulate catchment outflows satisfactorily while giving hydrologically meaningful estimates of internal variables.