The Impact of Urban Land Expansion on Cropland under Shared Socioeconomic Pathways in China

Urban land and cropland are two land-use types most significantly affected by human activities, serving as critical indicators for the United Nations’ SDG11 (Sustainable Cities and Communities) and SDG2 (Zero Hunger) . As a rapidly developing major economy, China has experienced accelerated urbanization in recent years, resulting in intensified conflicts between urban expansion and cropland protection, thereby reflecting the trade-offs between SDG11 and SDG2. Using remote sensing-based change data and projections of urban land expansion by 2030, this study applies GIS spatial analysis and indicator-based methods to explore the spatial and temporal characteristics of cropland occupation by urban expansion around the baseline year 2015, both at the national level and within major grain producing region. The study finds that: 1) The most significant cropland loss due to urban expansion is projected in the middle and lower reaches of the Yangtze River, while the Northeast shows the highest rate of decline. Among cities of different sizes, Type-I municipalities exhibit the greatest reduction. 2) In contrast to the national trend, urban expansion in major grain-producing areas is projected to exert an increasingly severe impact on cropland, particularly in the Huang-Huai-Hai Plain, the Southwest, and the Loess Plateau. Type-I and Type-IV municipalities within these regions show the most pronounced effects. 3) Under various Shared Socioeconomic Pathways, the sustainable development scenario has not effectively curbed cropland loss. Urban expansion continues to encroach upon cropland substantially, with cropland being the primary contributor to land conversion. These findings suggest that sustainable development scenarios should be adjusted to better incorporate food security concerns.