Spatial Vulnerability Analysis by using Geographic Information System (GIS) for achieving Healthy Cities

Abstract

This article examines the sensitivity of urban residents to health-related vulnerabilities based on spatial physical characteristics, using the case of Saraphi District in Chiang Mai Province. Historically, the area was the settlement of Wiang Kum Kam during the reign of King Mangrai, before large-scale flooding between 1558 and 1774 led to the abandonment of the site and subsequent relocation to establish the Lanna capital, now known as Chiang Mai. With the expansion of Chiang Mai City, a significant number of people have resettled in Saraphi District due to its proximity to both Mueang Chiang Mai District and Mueang Lamphun District. As a result, Saraphi has become a transitional urban zone between the two provinces and currently has the second-highest population density in Chiang Mai Province, following Mueang Chiang Mai District. Despite this urban expansion, the district continues to face recurring flood events in several subdistricts, including Pa Bong, Chomphu, Nong Phueng, Chaiyasathan, and Yang Noeng. In particular, the year 2024 experienced a severe flood disaster, attributable to the district’s topographical characteristics as a basin. Other environmental hazards also persist, such as extremely high temperatures and accumulated fine particulate matter (PM 2.5), which has contributed to Chiang Mai’s highest incidence of lung cancer. These conditions position Saraphi District as a high-vulnerability area in the region. The objective of this study is to investigate physical spatial data and identify factors influencing the health and well-being of residents living in vulnerability area. This assessment supports an analysis of spatial vulnerability and environmental risk within the frameworks of healthy cities, resilient cities, and sustainable urban development. The study employs a process of selecting appropriate indicators in combination with the method of principal component analysis and geographic information system–based spatial mapping to evaluate and classify risk levels. The research involved collecting physical spatial data from multiple sources and analyzing relationships among variables using principal component analysis to reduce redundancy and identify the primary factors contributing to actual spatial risk. The extracted components were then integrated with geographic information system analysis to generate spatial risk maps. This approach enabled the visualization of risk distribution patterns and the identification of areas with heightened sensitivity. The results identified three thematic categories comprising twelve indicators. Theme 1: Urban Development includes (1) population density, (2) building density, (3) historical sites, pagodas, and temples, (4) industrial areas, and (5) agricultural areas. Theme 2: Healthy City includes (1) haze and air pollution, (2) health-promoting public parks, (3) health-promoting schools, and (4) health-promoting hospitals. Theme 3: Resilient City includes (1) slope of terrain, (2) flood-prone areas, and (3) government service areas. Spatial vulnerability analysis classified Saraphi District into five risk levels: Very High Risk (highly sensitive areas): 15.44 square kilometers (13.91 percent), including Chaiyasathan and Yang Noeng Subdistricts. High Risk (moderately high sensitivity): 13.92 square kilometers (12.54 percent), including Tha Kwang and Nong Faek Subdistricts. Moderate Risk (medium sensitivity): 30.04 square kilometers (27.06 percent), including San Sai, Nong Phueng, and Don Kaeo Subdistricts. Low Moderate Risk (moderately low sensitivity): 19.27 square kilometers (17.36 percent), including Chomphu and Pa Bong Subdistricts. Low Risk (least sensitive areas): 32.33 square kilometers (29.13 percent), including Tha Wang Tan, Khua Mung, and Saraphi Subdistricts. The findings reveal significant spatial variation in vulnerability levels across the district. These results provide essential baseline information for prioritizing and planning sustainable urban development, while supporting the creation of a resilient city capable of effectively preparing for and responding to future disasters. Moreover, the outcomes align with provincial and national development strategies, including Sustainable Development Goal 11 on safe and sustainable human settlements, and the principles of healthy cities that emphasize environmental quality, access to health services, green open spaces, and improved air quality. Furthermore, the study’s results can be integrated into practical measures for planning, management, and the design of healthy urban environments that enhance resilience. This contributes to the development of adaptive risk management mechanisms that reflect local spatial contexts, strengthen the district’s capacity to cope with and recover from disasters, and ultimately improve the quality of life for residents in Saraphi District toward becoming a safe, healthy, and sustainable urban community in the long term.