Influence of urban forms on surface flow in urban pluvial flooding

This paper presents a systematic analysis of the influence of nine urban characteristics (distance between buildings, mean building size, building coverage, etc.) on surface flow in case of pluvial flooding. Time dependent stored volumes, outflow discharges and mean water depths were computed for a set of 2000 synthetic urban forms, considering various terrain slopes and return periods of the rainfall. An efficient porosity-based surface flow model was used to compute the 2D flow variables. Statistical analysis of the relationship between the flow and urban variables highlights that the flooding severity is mostly influenced by the building coverage.