Bangkok's Critically Vulnerable Districts to Urban Heat Stress

 The most vulnerable district in Bangkok to urban heat stress, according to the Heat Vulnerability Index (HVI) analysis conducted in the sources, is Samphantawong.

Samphantawong has the highest overall Heat Vulnerability Index (HVI) score. This score places it in the Critical Vulnerability tier, meaning it requires immediate and comprehensive heat mitigation interventions due to its extreme risk across multiple dimensions.

Vulnerability Ranking and Key Drivers

1. Samphantawong (HVI = 0.750)

Samphantawong's high vulnerability is primarily driven by its overwhelming exposure to heat and its dense, unmitigated urban environment.

• Heat Exposure Score: 1.000 (Maximum score). This district experiences the highest heat exposure among all districts.

• Heatwave Burden: It faces up to 100 heatwave days per season, with events lasting up to 40 consecutive days in the urban core.

• Lack of Green Space: It has minimal green space coverage, with a ratio of only 0.007.

• High Density: It suffers from the highest population density (14,242 people/km²).

2. Second Most Vulnerable: Pom Pram Sattru (HVI = 0.720)

The second most vulnerable district is Pom Pram Sattru, also falling under Critical Vulnerability.

• Heat Exposure Score: 0.981 (Nearly maximum exposure).

• Density and Green Space: Its vulnerability is driven by its nearly maximum heat exposure, minimal green infrastructure (0.018 ratio), and extreme housing density (30,192 units/km²).

3. Third Most Vulnerable: Bang Rak (HVI = 0.635)

Bang Rak is the third district in the Critical Vulnerability tier.

• Heat Exposure Score: 0.930 (Extreme heat exposure).

• Green Space: This is combined with very limited green space (0.018 ratio).

These critically vulnerable districts are all part of the dense, central business districts and historical center of Bangkok where vulnerability is concentrated. The high vulnerability reflects a strong correlation between urbanization intensity, reduced green spaces, and increased heat exposure, demonstrating the pronounced urban heat island effect in Bangkok's core.