Compared performance of a conceptual and a mechanistic Compared performance of a conceptual and a mechanistic

摘要

In order to investigate the hydrologic response of a green roof system within the urban environment, a monitoring campaign isncarried out at the green roof site of the University of Genova (Italy). Experimental data confirm that the green roof is able tonsignificantly mitigate the generation of runoff with median values of retained volume and peak reduction, respectively, equalnto 94 and 98%. A conceptual linear reservoir and a simple mechanistic (Hydrus-1D) models are implemented to simulatenthe hydrologic behaviour of the system; each model is calibrated and validated based on experimental data collected at thengreen roof site. The hydrographs simulated with both hydrologic models reproduce with acceptable matching capabilities thenexperimental measurements, as confirmed by the Nash-Sutcliffe Efficiency index generally greater than 0D60. Although thenrelative percentage differences evaluated for the selected hydrograph variables (the total effluent volume, the peak flow ratenand the hydrograph centroid) demonstrate that the mechanistic model is more accurate, prediction errors of the conceptualnmodel are generally limited when compared with the observed hydrologic performance. Results of the present comparisonnare useful in supporting conceptual model selection in case the hydrologic response is addressed for hydrologic performancenassessment. Copyright  2011 John Wiley & Sons, Ltd.