In recent years, extreme heat in Central Vietnam has become increasingly severe. Hue City has recorded some of its highest temperatures on record, with summer temperatures exceeding 42°C. While climate change is a major driver of rising temperatures, rapid urbanization, concrete surfaces expansion, and the decline of green spaces is also contributing to higher temperatures in urban areas.
A recent ISET study on urban thermal variation in Hue City during the 2014–2024 period reveals a clear relationship between green space loss and increasing urban heat. The findings provide scientific evidence to support green space planning and strengthen resilience to extreme heat.
Green Space Is Declining
Analysis of satellite imagery shows that green space in Hue’s central wards has declined significantly over the past decade. Across 12 central and peri-urban wards, green space decreased by approximately 20% between 2014 and 2024. This trend is closely linked to rapid urbanization, which has transformed agricultural land, gardens, ponds, and other vegetated areas into residential developments and urban infrastructure.
Areas Losing Green Space Are Getting Hotter
Analysis of summer land surface temperatures derived from satellite data reveals clear differences across the city:
- Hue’s urban core is consistently 4–8°C warmer than the citywide average.
- Peri-urban areas experiencing rapid urbanization are typically 1–4°C warmer than the city average, indicating that the Urban Heat Island effect is expanding beyond the city center.
- In contrast, rural areas with abundant vegetation and water bodies generally remain at or below the citywide average temperature.
- A comparison between Thuận Hóa Ward, a densely built urban area, and Quảng Điền Commune, a predominantly rural area, shows average summer temperature differences of up to 5–8°C. This highlights the important role that vegetation cover and water bodies play in regulating urban microclimates.
The study also found that areas experiencing green space loss are not only hotter but tend to maintain elevated temperatures for longer periods. This increases heat-related risks and can have significant impacts on public health and well-being.
Green Spaces: A Key Solution for Heat Resilience
The findings demonstrate that green spaces and water bodies play a critical role in regulating urban temperatures and reducing the impacts of extreme heat.
As climate change intensifies and urbanization continues, protecting and expanding green spaces should be recognized as a key adaptation strategy for cities like Hue. This includes preserving existing green areas, ensuring adequate tree cover and water features in new urban developments, and integrating green infrastructure solutions into urban planning and design.
Strengthening urban temperature monitoring systems and using remote sensing data to track changes in green space can also help local authorities identify emerging heat hotspots and develop more effective adaptation measures.
Read our study here.
By Tung Hoa Truong and Canh Toan Vu, ISET-International