Population growth and construction land expansion’s link to sustainable development has gained attention. This study investigated the urban–rural divergence in the population–construction land relationship in China’s Yangtze River Economic Belt (YREB) from 2000 to 2020 using census and land-use data. This study utilized an integrated urban–rural framework to discuss reasons for the disparity. The findings suggested the following: (1) A spatial mismatch formed between population distribution and construction land allocation in the YREB from 2000 to 2020. The mismatch gap in rural areas was larger than in urban areas. (2) The urban areas maintained double growth rates in the population and construction land, while rural areas experienced constant population loss accompanied by construction land expansion. (3) An expansive negative decoupling relationship dominated the urban population–land system, while a strong negative decoupling relationship dominated the rural population–land system. (4) Institutional factors, such as land financialization and urban–rural dualism, were major triggers for the mismatch between population and construction land. Policy responses such as a new type of urbanization and rural revitalization strategies can shape the population–land relationship’s evolution. Our comparative analysis of urban and rural areas highlights the population–land relationship’s complexity, promoting sustainable land-use planning in urban–rural spaces.

Previously, urban planning approaches have tended to convert local agglomeration into network connections to advance urban development. However, is this successful experience learned from developed counties appropriate for developing countries? Scholars hold different opinions on this debate. To answer this question, we need to examine the effects of urban agglomeration in developing countries with a quantitative method. In this paper, we introduced a method of examining network connections from a geospatial perspective to explore the practice and spatial consequences of regional integration using a new concept of “coupling distance” based on metal valence bond theory. Then we applied this method to conduct an empirical case study of the urban agglomeration in the middle reaches of the Yangtze River region in China. We found that: (1) the real integration scale of the investigated urban areas was less than one-fourth the planned area, as most of interactions between cities are local, although we see the positive facilitation of urban networks on cross-provincial integration. (2) In terms of spatial consequences, the study area demonstrated phenomena of “agglomeration shadows”, “enclaves” and “inverse integration”. Specifically, these “agglomeration shadows” were all in their province’s geometric centers, which seemed to have suffered a “central position curse”. (3) Both “enclaves” and “inverse integration” call for a readjustment of government-led regional integration planning. Differently, the former has a positive attitude towards integration while the latter holds the opposite attitude. This study hopes to provide operationalizing methods and guidelines for planners and decision makers in the field of regional integration planning.