The transition characteristics and driving mechanisms of rural residential land in metropolitan areas-a case study of Tianjin, China.

Rural revitalization is the core decision for eradicating global poverty and achieving shared prosperity, and one of the most important works is to optimize and manage rural land space. A theoretical framework based on urbanization theory was built to reveal the rural residential land transition in the Tianjin metropolitan area, China from 1990 to 2020. The transition features are identified by computing the land-use conversion matrix and the rural residential land expansion index (RRLEI) and the influencing factors and mechanisms through a multiple linear regression model. The spatial distribution of rural residential land shows that it expands from the inner suburbs to the outer suburbs, then diminishes in the outer suburbs, and extends to the Binhai New Area. Low-level conflicts between rural residential land and urban construction land occurred during the rapid urbanization period, resulting in disorganized and wasteful growth. The inner suburbs have edge-expansion, dispersion, and urban encroachment patterns; the outer suburbs have edge-expansion, infilling, and dispersion patterns, with little urban encroachment; and Binhai New Area has just an edge-expansion pattern. During decelerated urbanization stage, a high-level conflict occurred between rural residential land and arable land, forestland, grassland, water, and urban construction land. Dispersion grew as urban encroachment reduced in the inner suburbs; dispersion increased while urban encroachment declined in the outer suburbs; dispersion, infilling expansion, and urban encroachment increased in the Binhai New Area. During the saturation stage of urbanization, rural residential land evolved in tandem with other forms of land use, with more efficient land use and diverse uses. The main pattern of rural residential land in a suburban region is still edge-expansion, dispersion has expanded in the Binhai New Area, and urban encroachment is the way of urban development in the inner suburbs. Economic factors and economic location strongly impact the dispersion pattern. Edge-expansion and infilling patterns are impacted by comparable variables, including geographical location, topography, population resources, and economic location. Furthermore, the amount of economic growth influences the edge-expansion pattern. It might be influenced by land policy, and the eight elements have no substantial relationship with urban occupancy. Based on resource endowment and pattern features, certain optimization techniques are given.