Förorenade områdens sårbarhet för klimatrelaterade naturolyckor

Sammanfattning: Throughout history industries have been located adjacent to water courses to use water in the process, for transport and release of wastewater. This is also the case along the Arboga river. Due to climate change the estimated increase and greater variations in temperature and precipitation may induce a greater risk of flood, landslide and erosion along Arboga river, increasing the spread of pollutants to lake Mälaren- a source of fresh water for two million people. Polluted sites susceptible to natural hazards have been identified in Västmanland and Örebro counties (SGI 2012, Bäckström 2012). The Swedish Geotechnical Institute has developed a quick scan method and a model for vulnerability assessment with focus on contaminated sites (Edebalk et al., 2016, Göransson et al. 2016). A landslide susceptibility index (LSI) has been developed by Ströberg et al. (2017). I here present a GIS-method influenced by LSI and the scan method, that uses an index for incorporating the dispersion risk of pollutants with the degree of potential exposure (ISE), for regional supervision. The outcome is evaluated in three case studies and the vulnerability assessed using the method by Edebalk et al. (2016) and integrated in environmental risk assessment. The results of ISE show that the ranking is strongly affected by sites polluted with mainly organic substances, as the weight of flood is relatively low if exposing organic substances. ISE is greatly influenced by the degree of exposure and therefore affected by where the coordinate point is set, that the shape and size of the sites are like the buffer zones and how precise the layers of natural hazards are. The three sites impose a high to very high dispersion risk due to vulnerability to natural hazards. This would affect the risk class in at least one case, if considered in environmental risk assessment.