Abstract
Abstract. Fractal analysis relies on scale invariance and the concept of fractal dimension enables one to characterize and quantify the space filled by a geometrical set exhibiting complex and tortuous patterns. Fractal tools have been widely used in hydrology but seldom in the specific context of urban hydrology. In this paper, fractal tools are used to analyse surface and sewer data from 10 urban or peri-urban catchments located in five European countries. The aim was to characterize urban catchment properties accounting for the complexity and inhomogeneity typical of urban water systems. Sewer system density and imperviousness (roads or buildings), represented in rasterized maps of 2 m × 2 m pixels, were analysed to quantify their fractal dimension, characteristic of scaling invariance. The results showed that both sewer density and imperviousness exhibit scale-invariant features and can be characterized with the help of fractal dimensions ranging from 1.6 to 2, depending on the catchment. In a given area consistent results were found for the two geometrical features, yielding a robust and innovative way of quantifying the level of urbanization. The representation of imperviousness in operational semi-distributed hydrological models for these catchments was also investigated by computing fractal dimensions of the geometrical sets made up of the sub-catchments with coefficients of imperviousness greater than a range of thresholds. It enables one to quantify how well spatial structures of imperviousness were represented in the urban hydrological models.
Highlights
The aim of this paper is to consistently characterize urban catchment properties accounting for the complexity and inhomogeneity typical of urban water systems
Fractal analysis relies on scale invariance and the concept of fractal dimension enables one to characterize and quantify the space filled by a geometrical set exhibiting complex and tortuous patterns
In this paper we implementedfractal analysis in the context of urban hydrology on 10 catchments located in five European countries
Summary
The aim of this paper is to consistently characterize urban catchment properties accounting for the complexity and inhomogeneity typical of urban water systems. It is focused on two main properties of urban catchments, namely the geometry of the sewer system and the distribution of impervious surfaces Such characterization is important to obtain insights in the urban catchment response behaviour at the various spatial scales that control the relation between rainfall and sewer flows; to develop convenient methods that allow for evaluation of the urban catchment characteristics implemented in urban drainage models (the ones that are of importance for obtaining reliable spatially variable urban catchment responses; e.g. spatial imperviousness structure); to develop methods that support the urban hydrological modeller in the decision making process with regard to spatial details required to obtain reliable model (impact) results. Fractal analysis and more generally scaling analysis have been often and successfully used in geophysics, including hydrology, but seldom in the specific context of urban hydrology
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
