Modelling decentralised systems for urban drainage and flood mitigation

S Hellmers,N Manojlovic,G Palmaricciotti,P Fröhle

doi:10.1080/23249676.2015.1128368

S Hellmers, N Manojlovic + Show 2 more

Open Access

https://doi.org/10.1080/23249676.2015.1128368

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Abstract

Adapting to the impacts of climate change and urban growth in urban flood management requires approaches, which mitigate the flood risk and provide sustainable solutions. A combination of local drainage systems and water retention in public spaces may provide an appropriate strategy to cope with present and future pressures on the urban drainage infrastructure. To implement these small-scale hydrological systems in catchment models, novel hydrological modelling approaches are required that can handle a large number of spatially distributed measures. This paper presents the enhancement of a model system and the application for an urban catchment in Hamburg, Germany. The efficiency study of decentralised systems was conducted on the basis of climate change and urban growth scenarios. The results demonstrate the potential of sustainable drainage systems and multipurpose retention spaces for flood peak mitigation.

Highlights

Drainage infrastructures in urban areas prevent frequent flooding and protect water courses from combined sewage and stormwater runoff
In case of storm events that surpass the capacity of Sustaina-ble Drainage Systems (SUDS), the control of exceedance flow is of particular concern
This demands for a modelling approach which can handle a large number of spatially distributed measures and a sufficiently detailed land use map is required matching the spatial detail of the SUDS distribution in the model area

Summary

Introduction

Drainage infrastructures in urban areas prevent frequent flooding and protect water courses from combined sewage and stormwater runoff. Wong et al 2013, Zhou 2014) These measures treat or drain water in a more sustainable way by activating its natural behaviours and processes in the urban environment using infiltration, retention and storage (Zhou 2014). These measures consist of (mostly vegetated) source-control structures such as swales or green roofs, with a limited capacity and a specific design threshold. By linking those measures into a cascade of measures, an integrated system can be created

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