title: Should we trust build-up/wash-off water quality models at the scale of urban catchments?
abstract: Models of runoff water quality at the scale of an urban catchment usually rely on build-up/wash-off formulations obtained through small-scale experiments. Often, the physical interpretation of the model parameters, valid at the small-scale, is transposed to large-scale applications. Testing different levels of spatial variability, the parameter distributions of a water quality model are obtained in this paper through a Monte Carlo Markov Chain algorithm and analyzed. The simulated variable is the total suspended solid concentration at the outlet of a periurban catchment in the Paris region (2.3 km2), for which high-frequency turbidity measurements are available. This application suggests that build-up/wash-off models applied at the catchment-scale do not maintain their physical meaning, but should be considered as "black-box" models.
authors.affiliation: LEESU, MA 102, École des Ponts, AgroParisTech, UPEC, UPE, 6-8 Avenue Blaise Pascal, 77455, Champs sur Marne Cedex 2, France. Electronic address: celineb@leesu.enpc.fr.
authors.forename: Céline
authors.initials: C
authors.lastname: Bonhomme
authors.affiliation: Department of Analytical, Environmental & Geo-Chemistry (AMGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050, Brussels, Belgium.
authors.forename: Guido
authors.initials: G
authors.lastname: Petrucci
mesh_terms: D004784:Environmental Monitoring; D011891:Rain; D035501:Uncertainty; D014872:Water Movements; D060753:Water Quality
keywords: Black-box model; Build-up/wash-off model; Monte Carlo Markov Chain; Stormwater quality modelling; Urban catchment