The most vulnerable districts in Bangkok to urban heat stress are those located in the dense, central urban core, characterized by a confluence of high heat exposure and high population/housing density, resulting in a Critical Vulnerability ranking.
Based on a vulnerability analysis using the Heat Vulnerability Index (HVI), the top 10 most vulnerable districts are identified as follows:
Critically Vulnerable Districts (HVI > 0.6)
These three districts require immediate and comprehensive heat mitigation interventions due to their extreme vulnerability scores across multiple dimensions.
Rank | District | Heat Vulnerability Index (HVI) | Primary Vulnerability Drivers |
1 | Samphantawong | 0.750 | Driven by extreme heat exposure (1.000), minimal green space (0.007 ratio), and the highest population density (14,242 people/km²). |
2 | Pom Pram Sattru | 0.720 | Driven by nearly ** maximum heat exposure** (0.981), minimal green infrastructure (0.018 ratio), and extreme housing density (30,192 units/km²). |
3 | Bang Rak | 0.635 | Driven by extreme heat exposure (0.930) combined with very limited green space (0.018 ratio). |
Highly Vulnerable Districts (HVI 0.5 – 0.6)
These districts need targeted interventions addressing their specific vulnerability drivers.
Rank | District | Heat Vulnerability Index (HVI) |
4 | Pathum Wan | 0.592 |
5 | Khlong Toey | 0.560 |
6 | Ratchathewi | 0.554 |
7 | Din Dang | 0.536 |
8 | Sathorn | 0.519 |
9 | Khlong San | 0.519 |
10 | Wattana | 0.509 |
Khlong Toey is specifically noted as an area where informal settlement residents face extreme indoor heat due to insufficient cooling infrastructure and the "concrete jungle" effect.
Key Drivers of Vulnerability in Bangkok's Core
The overall high vulnerability in these central areas is due to the strong correlation between urbanization intensity, reduced green spaces, and increased heat exposure, reflecting the pronounced urban heat island effect.
1. Extreme Heat Exposure: The highly vulnerable districts consistently experience the highest heatwave burden in the Bangkok Metropolitan Area, facing up to 100 heatwave days per season, with events sometimes lasting up to 40 consecutive days.
2. Lack of Green Space: These districts have minimal green space coverage (e.g., Samphantawong has a 0.007 ratio). Central districts average temperatures exceeding 30°C and are up to 3°C warmer than the city's coolest areas.
3. Sensitivity Drivers: High sensitivity is found in districts like Ratchathewi (0.585), driven by demographic factors including the highest birth rate, which serves as a proxy for the presence of infants and young children, who are highly vulnerable to heat stress.
The vulnerability analysis utilized a comprehensive assessment framework that weighted Heat Exposure (40%), Heat Vulnerability (40%, combining demographics and built environment), and Behavioural Exposure (20%).
0 Comments