Pluviala översvämningar i stort och smått / Pluvial flooding in large and small scale
Urban, pluvial flooding severely effects infrastructure, buildings and urban life during and after extreme rainfall. In this study, spatial analyses of flood claims from insurance companies and the water utility company of Malmö, VA Syd, are used to better understand the mechanisms and characteristics of pluvial flooding. The same data sets are used to analyse how blue-green infrastructure impacts flood risk. Can blue-green infrastructure for handling of stormwater in urban green spaces be used as a strategy for resilient flood risk management? It was found that flooding during intense rainfall often is located closely to the main overland flow paths and the main sewers, while flooding during rainfall with longer duration seem to be more randomly distributed. Combined sewers are more affected by flooding than separate sewers. Blue-green infrastructure can reduce urban, pluvial flooding. The large-scale spatial distribution of flooding with respect to urban flow paths and drainage system are discussed in relation to the impact of small-scale surface water detention in e.g. detention basins and concave green spaces. The article is based on the authors doctoral thesis (Sörensen, 2018).