Evaluation of a distributed model for urban catchments using a 7-year continuous data series

The documentation existing on both land use and the delineation of pervious and impervious zones in urban areas tends to be rather complete. In addition, topographical information (altitudes, slopes) is generally available, although contours are not drawn in detail on urban-area maps. The development of urban databases has provided a convenient means of accessing this information for the purpose of hydrological modelling. The objective of this paper is to evaluate a recent model, 'SURF' (semi-urbanized runoff flow), specifically developed for coupling with a GIS based on a digital terrain representation. This model was evaluated by use of an original approach from the field of urban hydrology. A 7-year continuous data series, which includes the dry periods, has been used as input to run the model. The principles behind the SURF model are briefly described herein. A sensitivity analysis is then performed in order to select the most influential parameters. Following the calibration stage, the model's validation is discussed. This validation is conducted not only by comparing observed and simulated hydrographs, but also by comparing the SURF model with a more conventional model in urban hydrology, called the URBAN model. It is demonstrated that the SURF model provides useful simulation results and does outperform the URBAN model. Copyright (C) 2000 John Wiley & Sons, Ltd.