The Flash Floods Risk in the Local Spatial Planning (Case Study: Lublin Upland, E Poland)

Abstract

Flash floods pose a significant threat to humans but the state of our knowledge on the occurrence and related risk of such phenomena is insufficient. At the same time, many climate change models predict that extreme rainfall events will occur more and more frequently. Identifying areas susceptible to flash floods is more complicated that in the case of floods occurring in the valley bottoms of large rivers. Flood risk maps in Poland have not been developed for small catchments. The study objective was to assess whether the threat related to flash floods is taken into account in the spatial planning system of municipalities. Studies were conducted in the Lublin Upland, E Poland (an area of about 7200 km2). A preliminary assessment of susceptibility of 369 catchments to flash floods was carried out in a GIS environment using multi criteria analysis. The susceptible catchments cover about 30% of the area. Existing planning documents, flood hazard and flood risk maps were analyzed for municipalities located in the catchments with highest susceptibility to this phenomenon. Our results show that flash flood risk is usually not recognized at the level of local governments even when it is significant. Local planning documents do not take into account the existence of this threat.