Friday, June 13, 2025

Smart growth: How China's 30-year urban planning led to predominantly high-suitability city expansion

Science China Press

image:
Spatial distribution of urban expansion speed in China from 1990-2020. Red areas indicate high-speed expansion zones, orange shows medium-speed expansion, and pink represents low-speed expansion areas. The map clearly shows that the eastern region is dominated by high-speed expansion, forming three major expansion megaregions: Beijing-Tianjin-Hebei (b1), Yangtze River Delta (b2), and Guangdong-Hong Kong-Macao Greater Bay Area (b3); the central region exhibits medium-speed expansion; while western and northeastern regions are characterized by low-speed expansion.
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Credit: ©Science China Press

Scientists have created the first high-precision assessment of how China's massive urban growth over three decades has matched its geographical conditions and disaster risks, providing crucial insights for future urban planning and urban sustainability.

The study, published in Science China Earth Sciences, analyzed urban development across China from 1990 to 2020 – a period that saw the nation's urban construction land expand by 214% and urbanization rates surge from 26.4% to 66.2%.

"China has experienced the world's fastest and largest urbanization process, representing a remarkable achievement in national development," explains Dr. Kai Wang of the China Academy of Urban Planning and Design, the study's lead author. "Since the enactment of China's first urban planning law in 1990, a series of well-implemented urban planning policies have played a crucial role in guiding rational and orderly development across the country. This strategic approach has not only driven tremendous economic growth but also progressively shifted many cities from 'spatial mismatch' to 'spatial adaptation,' resulting in steady improvements in urban livability despite challenges posed by natural factors like floods, heatwaves, and seismic activity."

Using satellite remote sensing data, big data techniques, and comprehensive disaster risk assessments, researchers quantified how well urban expansion matched suitable land and measured cities' exposure to nine types of natural disasters.

The findings reveal distinct regional patterns. Urban development was concentrated in medium to high suitability areas (83.23% of expansion), but 14.46% of urban growth occurred in the lowest suitability areas, predominantly in eastern coastal and western regions.

From a safety perspective, approximately half of urban development took place in areas with medium to highest safety levels, yet 13% of urban expansion areas exhibit relatively high safety risks.

The study identified clear regional risk variations:

Eastern coastal regions primarily face water-related threats (heavy rain, floods, typhoons, storm surges), with urban expansion in these risk areas accounting for 62% of regional growth
Western regions are mainly threatened by geological earthquake risks, with urban expansion in these risk zones exceeding four times that of other regions
Central regions primarily face high-temperature disaster risks, with heatwaves affecting over 83% of urban expansion areas
Northeastern regions contend with extreme cold and snow-related disasters, affecting nearly 61% of urban expansion

The researchers identified distinct regional development patterns, described as: "high-suitability and high-expansion in eastern regions, medium-suitability and medium-speed expansion in central regions, low-suitability and low-expansion in western regions, and high-suitability and slow-expansion in northeastern regions."

The study provides valuable insights for China's "Beautiful China" initiative and offers scientific guidance for creating safer, more resilient cities. As climate change intensifies extreme weather events, understanding these spatial patterns becomes increasingly crucial for sustainable urban development.

Dr. Wenhui Kuang, corresponding author from the Institute of Geographic Sciences and Natural Resources Research at the Chinese Academy of Sciences, emphasized the practical implications: "Our findings provide scientific guidance for high-quality regional development and resilient urban safety, supporting the coordinated development of differentiated regional socioeconomic and ecological systems."

The research team developed a new theoretical framework for precise spatial adaptation, which quantitatively analyzes spatial resource carrying capacity in urbanized areas. This approach allows for more accurate monitoring and evaluation of urban spatial adaptation and safety resilience, enabling timely adjustments in urban planning.

As China looks toward future urban growth with an additional 255 million urban residents expected by 2050, this study offers crucial insights for creating safer, more livable cities adapted to their specific regional conditions and disaster risks.

See the article:

Wang K, Kuang W, Fang W, Dou Y, Chen M. 2025. Spatially explicit adaptation characteristics of urban development and construction across China over the past three decades. Science China Earth Sciences, 68(5): 1624–1640, https://doi.org/10.1007/s11430-024-1545-0