Urban shrinkage has become a topic of major concern to scholars of geography and urban science. However, the methods of identifying urban shrinkage and growth have mostly focused on traditional statistical methods, and studies based on nighttime light (NTL) data are rare. Here, we use the NTL data for 56 months from 2012 to 2019 obtained by the Visible Infrared Imaging Radiometer Suite (VIIRS) on board the Suomi National Polar Orbiting Partnership (NPP) to identify the shrinkage and growth patterns of Yichun in China, by calculating the slope of the NTL radiance value after denoising. At the same time, by combining high-resolution Google satellite images and traditional demographic data, we analyzed the shrinkage characteristics of Yichun. The results of the study confirmed the characteristics of partial shrinkage in China’s shrinking cities. In addition, the use of NPP-VIIRS NTL data was able to more accurately identify the urban shrinkage and growth patterns, and may also be seen to present a more objective picture of reality, thus providing a new perspective for studies of urban shrinkage.

As populations continue to be concentrated in cities, the world will become entirely urbanized, and urban space is undergoing a drastic evolution. Understanding the spatial pattern of conversion and expansion of functional urban land, in the context of rapid urbanization, helps us to grasp the trajectories of urban spatial evolution in greater depth from a theoretical and practical level. Using the ESRI ArcGIS 9.3 software platform, methods, such as overlay analysis, transition matrix, and kernel density estimation, were used in order to analyze the spatiotemporal characteristics of different types of functional urban land conversion and expansion in the central city of Changchun. The results show that different types of functional urban land were often expanded and replaced, and the urban spatial structure was constantly evolving. The conversion and expansion of functional urban land show similar characteristics to concentric zone and sector modes and show dynamic changes in different concentric circles and directions at different periods. Our method can accurately identify the different types of functional urban land, and also explore the evolutionary trajectory of urban spatial structure. This study will help to coordinate the development of different functional urban spaces and to optimize the urban spatial structure in the future.

The growth and shrinkage of cities and towns are normal phenomena in the evolution of regional town systems. The growth and shrinkage of different levels of cities and towns are mutually influential. This study uses ArcGIS and the Hierarchical Linear Model to analyze the hierarchical differences and correlations in the characteristics and mechanisms of shrinking cities and towns in Northeast China from 2000 to 2020. The results indicate that the shrinkage of cities and towns is characterized by hierarchical differences. High-level cities show widespread and slight shrinkage, while low-level towns show the most severe and continued shrinkage. The population shrinkage of cities and towns within the same municipality is not fully synchronized. In terms of spatial patterns, the multi-level relationship between cities and towns is divided into growth-driven, central siphon, peripheral growth, local growth, and global shrinkage. The shrinkage of high-level cities is mainly influenced by economic and industrial development and built-up environment. The shrinkage of low-level towns is constrained by population concentration, economic development, enterprise scale, local arable land resources, and environmental quality. Wages, jobs, and infrastructures in high-level cities have a strong siphoning effect on low-level towns, while technology and industrial development drive the population and economic development of low-level towns.

The imbalance between urban and rural development has increased socio-economic challenges. Urban–rural integration has become an important strategy for addressing disparities in development between urban and rural areas in China. The digital economy offers new opportunities to advance urban–rural integration. This study constructs an evaluation index system to assess the degree of urban–rural integration and examines the development of the digital economy in Northeast China from 2010 to 2020. It also studies the impact of the digital economy industry on urban–rural integration. The findings are as follows: (1) The development of the digital economy industry in Northeast China has a significant positive effect on urban–rural integration. (2) The influence of the digital economy industry on urban–rural integration varies across regions, with a stronger effect in areas with a moderate concentration of digital economy industries, non-border regions, and Jilin Province. (3) The facilitative effect of digital economy industries on urban–rural integration diminishes as urban economic levels rise, with two critical thresholds; after surpassing the first threshold, the promoting effect of the digital economy weakens noticeably, and after crossing the second threshold, the effect further declines. Based on these findings, the study offers policy recommendations. The research findings of this paper enrich the theoretical framework for urban–rural integration driven by the digital economy, provide a strong foundation for promoting the digital economy and urban–rural integration in Northeast China, and offer valuable empirical references for other regions exploring urban–rural integration pathways.

The pioneers who started the gentrification process have contributed significantly to the activation of gentrified neighborhoods, but are often overlooked in top-down urban governance strategies. We studied the core participants, who were avant-garde café owners, in the initial stage of the commercial gentrification of Mudan Street in Changchun, China. By participatory observations and in-depth interviews, we closely investigated the statuses, behaviors, and preferences of the early gentrifiers, their contributions to block revivals, and the impacts of urban renewal policies on the gentrifiers themselves. Our conclusions are as follows. Most early gentrifiers were young and highly educated. They started the process of gentrification by youth culture production, which exhibited idealistic operating behaviors, such as the decoration of shops, creation of cultural atmospheres, and organization of cultural activities. They were the pioneers who drove bottom-up block renewal, reshaped traditional blocks into youth cultural consumption centers, and stimulated commercial vitality. However, commercialization was followed by soaring rents and increasing business competition that have forced many pioneers with low economic capital to leave. Furthermore, urban governance has had strong impacts on block renewal and gentrification. Inclusive management has promoted bottom-up neighborhood renewal, whereas arbitrary management has quickly destroyed the cultural landscape and business atmosphere, thereby accelerating the displacement of the pioneers. This study provides new evidence for gentrification theories, and offers a practical reflection for urban governance by constructing the profiles of early gentrifiers and discussing the paradox of gentrification in the context of urban China.

When explaining urban land use patterns, traditional theory neglects differences in the relationship between different types of transport routes and land use development. The purpose of the research presented here is to provide an analytical framework and an empirical analysis for studying differences in impacts of transport routes on land use and to identify the hierarchical variation in the transportation–land use relationship. With regard to Changchun city, at the city-wide scale there are significant differences in the dependence of three land use types on particular transport routes. At the microscale, the intracity transportation–land use connection exhibits a corridor effect; that is, newly constructed transport routes trigger quantitative and distributed adjustment of urban land along the routes, and adjustment closer to the transport routes tends to be more intensive than adjustment farther away. Moreover, there is a statistically significant difference in the corridor effects of different types of transport routes on particular land uses.