Risk Mapping and Evacuation Analysis of Vulnerable Population under Climate Change - a Case Study in New Taipei City, Taiwan.

The objective of this study is to investigate the flooding effect on the evacuation safety of vulnerable populations in the context of disaster response and climate change impact. The case study of New Taipei City, Taiwan, is introduced. Initially, we establish an urban flood drainage model, NTU-2DFIM, which includes a watershed rainfall-runoff model, a one-dimensional hydraulic model for regional drainage and stormwater sewers, and a two-dimensional surface flood model. After calibration and validation, the IPCC AR6 RCP8.5 climate change scenario is applied to simulate the flooding. Regarding vulnerable groups, which include the elderly (65 years and above), children (5 years and below), low to middle-income households, people with disabilities, solitary elderly individuals, and individuals with no formal education, a spatial autocorrelation analysis is conducted using the Basic Statistical Area to identify hotspots of vulnerable populations. Subsequently, in these hotspot areas, together with nearby evacuation shelters, service coverage analysis is performed. Additionally, road network analysis is conducted by considering flood-induced obstacles to determine optimal evacuation routes. With the above risk mapping process, the results can guide individuals in formulating emergency response plans for household and community, as well as providing public authorities with insights for adjusting shelter locations and planning transportation for the evacuation of vulnerable groups.