Development and application of a distributed catchment-scale hydrological model for the River Ythan,NE Scotland

Mathematical models are being used to develop a decision support system for integrated management of the Ythan catchment in NE Scotland. One component of this has involved the development of a distributed catchment-scale hydrological model. The model is based on subsurface flow routing and calculates the contribution to stream flow from each 50 m×50 m cell in the 548 km² catchment. It uses two topographic parameters, slope and distance to stream following the main line of flow, and five physical parameters. The topographic analysis and distributed flow accumulation are performed by linking the single cell model with a geographic information system. Preliminary results from a three-year simulation of daily flows indicate that the model successfully predicts the main characteristics of the catchment flow. © 1998 John Wiley & Sons, Ltd.