Coastal economic vulnerability to sea level rise of Bohai Rim in China

Through index-based method, the coastal economic vulnerability of Bohai Rim in China to the hypothetical local scenario of 1-m relative sea level rise by the end of twenty-first century was assessed (note that 1-m global sea level rise throughout the twenty-first century is highly improbable). Both physical and socioeconomic variables were considered, and the comparison between physical vulnerability and economic vulnerability was conducted to identify effects of socioeconomic variables on coastal susceptibility to sea level rise. The assessment was carried out at shoreline segments scale as well as at county-level scale, and the results were as follows: The combination of geomorphology and terrain plays the determinant role, since the gently sloped coasts with softer substances are always both physical and economic susceptible to the projected inundation scenario; potential displaced population and GDP loss have more influence on economic vulnerability than reclamation density in that the most intensively reclaimed areas are not always high vulnerable, while the areas that may suffer from the largest potential displaced population and GDP loss are always high vulnerable; the method employed in this study is sensitive in identifying the relative difference in economic vulnerability; moreover, it is capable of handling the issues caused by mutual offset effects between land-controlling impacts and marine-controlling impacts. The insights offered by this study could inform the coastal managers in optimizing allocation of limited resources and, consequentially, assist them to sequence policy, planning and management choices efficiently and effectively to adapt to the sea level rise.