Sensitivity analysis of typhoon-induced floods in coastal cities using improved ANP-GIS

This study developed an analytical network process (ANP) incorporated into a geographic information system (GIS; abbreviated as ANP-GIS) to assess flood sensitivity in coastal cities. A new consulting process is proposed to improve the ANP analysis by determining range scores of assessment factors. Compared with the original analytical hierarchy process (AHP) combined with GIS (AHP-GIS), the improved ANP-GIS with new consulting process can effectively consider the interrelationships of assessment factors between the index and sub-index layers. To verify the efficiency of ANP-GIS with new consulting process, both AHP-GIS and ANP-GIS were adopted to assess the exposure of sensitivity to typhoon-induced floods in the coastal cities of Guangdong Province. The results were validated by historical typhoon-induced flood records, revealing that most of the typhoon-induced floods were in the region with the assessed higher and highest flood sensitivities. The percentage of the highest flood sensitivity from the improved ANP-GIS with typhoons was twice that of the AHP-GIS. When considering typhoons, the higher and highest flood sensitivity levels increased from 29% to 48%, as indicated in this study. The assessment results from the improved ANP-GIS were closer to the historical records and better than the performance of AHP-GIS.