Characteristics and Influencing Factors of Cropland Function Trade-Off in Highly Urbanized Areas: Insights from the Yangtze River Delta Region in China

Exploring the characteristics of changes in cropland function trade-off and the influencing factors in highly urbanized areas can promote the synergistic development of urbanization and fine cropland management. Taking the Yangtze River Delta region as the study area, this paper developed a cropland function evaluation system from the production–ecology–living perspective, identified the spatial and temporal changes in cropland function trade-offs through Wavelet analysis and Root mean square error, and explored the driving factors of the trade-offs by using GeoDetector. The results indicated the following: (1) The cropland function in the Yangtze River Delta region has undergone a transition from a single production function to a composite function integrating ecology and life in conjunction with urbanization. The trade-offs between cropland functions are weakened, and the rate of decline from 2010 to 2023 is significantly higher than that from 2000 to 2010, and the characterization of cropland in different types of cities is revealed. (2) The turning points of cropland function trade-off changes in cities of different scales diverge, with the inflection points of small and medium-sized cities and large cities shrinking toward the center (decreasing from 42–48 km to 30–36 km), and metropolises showing an obvious trend of outward expansion (expanding from 42 km to 60 km). (3) The influence of natural and socioeconomic factors on cropland function trade-off intensity generally increases over time, with socioeconomic factors increasingly becoming significant drivers of the trade-off intensities. It is recommended that the study area focus on developing cropland characterization in different types of cities in the future, and continue to improve the degree of sharing the integration of profits from cropland functions, so as to promote optimal development.