Urban resilience and heat vulnerability of Bangkok's informal settlements: a GIS case study

Thesis Abstract

Urban heat exposure and climate resilience in Bangkok’s informal settlements pose critical urban sustainability challenges due to dense housing, limited green space, and precarious infrastructure. This study aims to assess heat vulnerability and urban resilience within these communities using a GIS-based case study to inform targeted adaptation strategies. The specific objectives are (1) to map spatiotemporal patterns of land surface and air temperature across informal settlements; (2) to quantify exposure, sensitivity, and adaptive capacity indicators at household and community levels; (3) to examine the relationship between built-environment attributes (density, materials, shade, ventilation) and heat risk using multivariate regression; (4) to evaluate the effectiveness of existing coping mechanisms and community-led adaptation efforts through semi-structured interviews; and (5) to propose a GIS-based resilience framework integrating local knowledge with urban planning indicators. The research adopts a mixed-methods design, combining quantitative GIS analyses with qualitative insight to ensure depth and generalizability. The population encompasses residents of five major informal settlements in Bangkok, with a purposive sample of 400 households for survey administration and 60 key informants from community organizations, local authorities, and NGOs. Data collection instruments include high-resolution remote sensing data (Landsat 8 and Sentinel-2 for thermal bands), municipal census and housing data, a structured household survey (comprising 60 items on heat exposure, coping capacity, and socio-economic status), and a semi-structured interview protocol. Validity and reliability are established through pilot testing (n=40), Cronbach’s alpha for scale constructs (target ?0.70), and triangulation across GIS-derived indicators, survey responses, and interview transcripts. Data analysis employs spatial statistics and regression modeling to quantify heat exposure and vulnerability, including Moran’s I for spatial autocorrelation, geographically weighted regression (GWR) to capture local variation, and hierarchical linear modeling to link resilience indicators with household outcomes. A conceptual model grounded in the Technological-Environmental-Social-Economic (TESE) resilience framework and drawing on the Theory of Planned Behavior for behavioral adaptation will guide interpretation. Expected findings indicate that informal settlements experience elevated land surface temperatures and heat indices due to high albedo loss, limited albedo-reducing materials, and scant vegetation, with heat vulnerability amplified by low income, high occupancy density, and inadequate access to cooling and water. The analysis anticipates significant associations between building materials (e.g., metal roofs), lack of shade, and increased indoor temperatures, as well as reductions in vulnerability linked to community-based cooling centers and participatory planning processes. The study contributes to knowledge by integrating high-resolution heat mapping with socio-spatial vulnerability indicators in a Southeast Asian megacity, advancing a participatory GIS resilience framework tailored to informal settlements, and informing policy on equitable heat mitigation and urban design. The main conclusion expected is that urban resilience in Bangkok’s informal settlements hinges on integrated interventions combining retrofit of housing and micro-infrastructure, expansion of green and shaded spaces, and formal recognition of community-led adaptation planning within municipal governance. Policy and practice recommendations include prioritizing heat-muffer zoning in settlement upgrades, subsidizing reflective roofing and shading, deploying mobile cooling and water-sharing schemes, and establishing participatory monitoring mechanisms using GIS dashboards to track progress and adapt strategies over time.