Univ.-Prof. Dr. Jürgen Breuste, head of the Research Group Urban and Landscape Ecology, University of Salzburg.
Ass.-Prof. Dr. Angela Hof, Research Group Urban and Landscape Ecology, University of Salzburg.
PhD project – sensitive, adaptive and regenerative management of flooding risk in urban areas:
Research topic and background: Sustainable Urban Drainage Systems (SUDS)
* Conventional flooding risk management practices
Currently, flood risk management in most European urban areas is characterised by underground drainage systems, enabling fast conveyance of stormwater out of the city to receiving waterways. While this paradigm has become mainstream, its underlying principles, together with the high degree of imperviousness of urban surfaces, translate into a severe shift in surface runoff patterns, as imperviousness and fast conveyance entail an intense reduction in infiltration and evapotranspiration, and subsequently an increase of flooding risk.
* SUDS as an alternative
In order to respond to these shortcomings, alternative approaches based on decentralised solutions have been proposed and deployed to handle the volume and rate of stormwater. These systems, entitled, inter alia, Sustainable Urban Drainage Systems (SUDS), are constituted by above ground soft structures, where natural processes are mimicked (infiltration, evapotranspiration, filtration, retention, reuse) in order to address flood risk.
* Research gaps
The development and adoption of such systems has led to the emergence of a vast body of research especially addressing their performance in terms of flood risk mitigation. Nevertheless, while a lot of endeavour has been undertaken in the modelling of overland flow, much less emphasis has been put on issues of power, actors’ agency and institutional work related to their implementation, as well as on the potential for radical social and technical change towards a more sustainable (e.g. sensitive, regenerative and adaptive) handling of flooding risk in urban areas that their adoption offers. By means of this research project, it is intended to respond to these research gaps.
* Overall aim of the project
The overall aim of the project is: to develop a model and subsequently assess the existing interplay among: a) flooding risk alleviation infrastructure, b) institutional work, c) relations of power and d) actors’ roles, during transition processes from conventional flood risk management practices to a sensitive, adaptive and regenerative flood risk management paradigm. To that end, 2 typologies of urban areas (district level) are evaluated with the model created: a) eco-quarters where SUDS have been deployed on the one hand, and b) conventional analogous quarters where traditional approaches to tackle floods (i.e. fast underground conveyance systems) are prevalent on the other hand. This approach is expected to enable us to gain an insight on the potential for radical change (both social and technical) offered by creating work on SUDS, hence on the degree of social and technical sustainability transitioning that such technical innovation and all related institutional work, power issues, etc. make possible.
Moreover, 2 distinct socio-ecological contexts, where dissimilar challenges and opportunities are faced concerning floods (i.e. the urban area of Linz (Austria) on the one hand, and the urban area of Toulouse (Southern France) on the other hand), are analysed. This methodological scheme makes possible to respond to 2 additional sub-targets:
– To discern and generate hypotheses on possible general guidelines among distinct socio-ecological contexts regarding the issues aforementioned (i.e. existing interplay among flooding risk alleviation infrastructure, institutional work, relations of power and actors’ roles, during transitions in the flooding risk management socio-technical system; and potential for radical change).
– To draw hypotheses on the way how an enabling context for radical to a water sensitive, adaptive and regenerative paradigm, in the actual urban flooding risk management paradigm, can be set up.
SUDS in the Solar City (Linz, Austria)
SUDS in Viala-Est (left) and Coste Rousse (right) (Prades-le-Lez, Southern France)