RAINFALL-RUNOFF MODELING OF THE OUSE BASIN, NORTH YORKSHIRE - AN APPLICATION OF A PHYSICALLY-BASED DISTRIBUTED MODEL

A physically based distributed rainfall-runoff model is applied to the basin of the River Ouse, North Yorkshire, with a catchment area of 33 15 km(2). The model includes a description of overland flow, subsurfac e flow, vertical water transfer in the soil, evapotranspiration, and c hannel flow in the river network. The finite-element schematization of the catchment provides a representation of the drainage network and t he spatial pattern of topography, soils, and meteorological inputs. Mo st of the parameters of the model are determined on the basis of the t opography and measured soil characteristics. Other parameters are cali brated using 15 min rainfall and flow data for six flood events and da ily rainfall and runoff data for 1986. Temporal disaggregation based o n the average variability method of Pilgrim et al. (Civ. Eng. Trans. I nst. Eng. Aust., CE11: 9-14, 1969) is used to generate hourly estimate s of rainfall from daily measurements. Model simulations are compared with daily flow measurements for the years 1987-1990. Results show tha t the model can simulate catchment outflows satisfactorily while givin g hydrologically meaningful estimates of internal variables.