Spatial characteristics on grass-roots space of metropolitan urban-rural transition zone

The space on the 30-150 m scale in the urban-rural transition zones belongs to an urban grass- roots space system that has obvious changes in development. In this paper, a multifractal analysis is carried out to reveal the evolution law of these zones, and the construction lands in Zhengzhou, Hangzhou and Beijing are taken as examples. Specifically, this study presents the multifractal characteristics by dividing three spatial evolution subsystems, according to generalized and typical f(a)-a(q) curve. Therefore, this paper makes a quantitative analysis of the spatial multifractal characteristics, taking the courtyard group level-neighborhood committee level space in the urban-rural transition zone as the research scale interval. The analysis shows that, the evolution of the zones belongs to adaptive change which is under the influence of macro-middle space, so its market-driven overtones are striking. On the whole, the evolution of grass-roots space is complicated in the rural-urban transition zone. Within a certain scale interval, generalized and typical spatial multifractal characteristics and their corresponding patch density (q) distribution areas are formed. Moreover, the evolution intensity of multiple spatial subsystems is usually different under the influence of various development processes and other factors, and their spatial composition also presents dynamic changes at various scales. And so, the spatial evolution of this zones is "situational". However, the grass-roots space of urban-rural transition zone is not a necessary continuation process from small and medium cities→traditional metropolises→modern metropolises→megacities. Its changes should be related to the status of the city in the urban system, more with the specific situation of urban-rural integration. The theoretical contribution of this paper is, to extend the typical multifractal characteristic system to more extensive evolution characteristic and degradation characteristic systems on the basis of satisfying the global and local indices. Thus, the nonlinear description of real development state of geographic space is enhanced. © 2023 Science Press. All rights reserved.