Urban Green Cover and Land Surface Temperature in Ho Chi Minh City: A Remote Sensing Analysis of Vegetation Cooling Effects Across Historical Development Rings, 1990–2025

Ho Chi Minh City's 11.3 million residents live in a landscape shaped by four political regimes — French colonial, wartime, socialist, and market-era — each of which built the city it needed and left the green space debt for the next. Using Sentinel-2 and Landsat satellite imagery from 1990 to 2025, we map vegetation cover and surface temperature across the city at 100-meter resolution and trace how each historical layer lost its green. The city shed 130 km² of vegetation between 2000 and 2020. Today, 36 wards forming a contiguous concrete belt — home to 3.5 million people — have critically low canopy cover, and three wards are true "green deserts" where 327,000 residents cannot walk to adequate vegetation in any direction. Dense green areas are over 4°C cooler than concrete surfaces. The results show that HCMC's heat burden is not random — it is a map of planning decisions made decades ago.