Indicator-based approach for flood vulnerability assessment in ancient heritage city of Hoi An, Central Region of Vietnam

The increasing unpredictable floods due to the effect of climate change across regions of Vietnam have threaten the country’s socio-economic development goals at local, regional and national scales. This paper employs indicator-based approach to calculate Flood Vulnerability Index and generates vulnerability maps that reflect the spatial distribution of flood vulnerability in the Central region of Vietnam, which is the hardest hit flood region and home to many sites of great cultural-historical value. Data were collected from Hoi An’s 2020 statistical yearbook, digital elevation model, land use map, open street map and from surveying experts and civil servants at the city level (representatives of the City People’s Committee, the Center for Cultural Heritage Management and Preservation of Hoi An) and at ward/commune level (representatives of 12 wards and communes). GIS techniques and analytical hierarchy process were applied to analysis the obtained data and generate three scenarios that reflect the impact of vulnerability’s components. The findings indicate that number of organizations in disaster prevention and historical site preservation, road density, the presence of historical sites, flood frequency and average elevation are the key factors affecting the city’s vulnerability to flood hazard in the area of cultural heritage. The empirical results in Hoi An also indicate the importance of the number of poor households as an necessary factor when considering the sensitivity to flood in developing countries. In addition, this study distinguishes the impact of vulnerability’s components by generating different scenarios which clearly proof that having more floods does not always mean high vulnerability and vice versa. More importantly, by looking into the reasons (either transportation, education or other indicators) that leads to the gap between Flood Vulnerability Index in different scenarios, the paper subsequently identifies measures for each locality, whereby the governmental investment budget can be prioritized effectively.