The interplay and synergistic relationship between urban land expansion and urban resilience across the three principal metropolitan regions of the Yangtze River Basin

The rapid expansion of urban land is considered one of the primary factors contributing to the enhancement in climate extremes in both frequency and severity. But the effects of urban land expansion on climate extremes are presently unclear, especially in geographically and climatologically complex China. This study investigates evolution laws of temperature and precipitation extremes from 1960 to 2022 over five national-level urban agglomerations in China and explores evolution trends in those under urban land expansion using the WRF model. The results show that the variation characteristics of temperature extremes over urban agglomerations in China show higher consistency compared to precipitation extremes under global warming and urbanization. Both the intensity and frequency of temperature extremes have significantly increased, but those of precipitation extremes have sometimes decreased rather than increased. Furthermore, both temperature and precipitation extremes will strengthen with urban land expansion. Around 30% of the enhancement in temperature and precipitation extremes can be attributed to urban land expansion. The temperature extremes of urban agglomerations at lower latitudes are more significantly affected by urban land expansion, but no significant spatial distribution law is observed in precipitation extremes. The results of this study could provide a scientific reference for better coping with extreme climate changes in urban areas and achieving sustainable development.

With the rapid development of urbanization in Henan Province, it is of great significance to study the relationship between man and land in regional cities to grasp the quality of urban development and to promote the healthy development of urbanization. In this paper, data envelopment analysis (DEA), Kernel density analysis, gravity center model and Logistic model are used to analyze the evolution and coordination of urban population growth and land expansion in 18 cities of Henan Province from 2000 to 2014, and to predict their overall development trend. The results show that: (1) the urban land expansion rate in Henan Province is faster than the population growth rate on the whole, the spatial distribution of the two increment is mainly in Zhengzhou, Luoyang, Luohe and other core cities, and Anyang, Nanyang, Nanyang, etc. (2) the center of gravity of urban population and the center of gravity of land are both located in the southeast of Zhengzhou City, and the coordination relationship between them presents the situation of Enhancement, Stability and Enhancement; The spatial coordination between urban land expansion and population growth is weak, and the land advance development is the main factor. (3) before 2003, the urban population growth and land expansion kept in sync, The forecasting results show that slowing down the expansion of urban land properly and coordinating the relationship between human and land will be the future direction of urbanization in Henan Province.

The conversion of Earth's land surface to urban uses is one of the most irreversible human impacts on the global biosphere. It drives the loss of farmland, affects local climate, fragments habitats, and threatens biodiversity. Here we present a meta-analysis of 326 studies that have used remotely sensed images to map urban land conversion. We report a worldwide observed increase in urban land area of 58,000 km2 from 1970 to 2000. India, China, and Africa have experienced the highest rates of urban land expansion, and the largest change in total urban extent has occurred in North America. Across all regions and for all three decades, urban land expansion rates are higher than or equal to urban population growth rates, suggesting that urban growth is becoming more expansive than compact. Annual growth in GDP per capita drives approximately half of the observed urban land expansion in China but only moderately affects urban expansion in India and Africa, where urban land expansion is driven more by urban population growth. In high income countries, rates of urban land expansion are slower and increasingly related to GDP growth. However, in North America, population growth contributes more to urban expansion than it does in Europe. Much of the observed variation in urban expansion was not captured by either population, GDP, or other variables in the model. This suggests that contemporary urban expansion is related to a variety of factors difficult to observe comprehensively at the global level, including international capital flows, the informal economy, land use policy, and generalized transport costs. Using the results from the global model, we develop forecasts for new urban land cover using SRES Scenarios. Our results show that by 2030, global urban land cover will increase between 430,000 km2 and 12,568,000 km2, with an estimate of 1,527,000 km2 more likely.

Regional integration plays a pivotal role in the socio-economic advancement of various global regions and is closely linked with the expansion of construction land. This expansion is a major contributor to urban carbon emissions. Utilizing a geographical regression discontinuity design (GRDD), this paper estimates the impact of urban construction land expansion on carbon emissions and explores the underlying mechanisms within the regional integration process of the Yangtze River Delta (YRD), China. The findings reveal that urban construction land expansion significantly influences carbon emissions, displaying an inverted “U”-shaped pattern. Furthermore, this expansion affects carbon emissions through the transformation of industrial structures, shifts in consumption patterns, and enhancements in scientific and technological investments. Our findings span the performance of the Yangtze River Delta from its early development stages to a relatively mature phase. This paper also partially reveals how the Yangtze River Delta, with both megacities and large- to medium-sized cities, manages urban construction land expansion during the integration process and strives for low-carbon emissions reduction. These results can provide green growth recommendations that balance socio-economic development, low-carbon emissions, and social equity not only for other urban agglomerations in China but also for similar regions in other developing countries by altering construction land utilization patterns.

This paper analyzed the spatial patterns of urban population changes and urban land expansion. Studies show that population concentrated into Adjacent Suburb Districts from Central City Districts and Remote Suburb Districts and Counties are the main characteristic of urban population changes of Beijing since 1982. Urban land expansion mainly took place in the central city and the surrounding areas. Starting at the central city, expanding along the main traffic lines and outspreading from a few hot spots are the main characteristics of urban land expansion in 1990s. Along with the fast expansion of urban and rural construction land, cropland and forestland area reduced notably and mainly converted into urban and rural construction land. It is obviously that urban population gathering to Adjacent Suburb Districts constantly caused the sprawling expansion of urban land and the sprawling of central city caused a lot of urban problems.

Promotion incentives for local officials and the expansion of urban construction land in China: Using the Yangtze River Delta as a case study

Identifying the relationship between urban land expansion and human activities in the Yangtze River Economic Belt, China

Detailed studies on the spatiotemporal patterns of urban agglomeration in the Middle Yangtze River Basin (MYRB) are rare. This paper analyzed the spatiotemporal patterns of urbanization in the MYRB using multi-temporal remote sensing data circa 2000, 2008 and 2016 integrated with geographic information system (GIS) techniques and landscape analysis approaches. A multi-level analysis of the rate and intensity, type as well as the landscape changes of urban expansion at regional, prefectural and inner-city levels was performed. Results show that the MYRB experienced rapid urban expansion with an annual expansion rate of 3.199%, especially in the Chang-Zhu-Tan and Poyang Lake metropolitan areas. The small and medium cities presented faster urban expansion than the larger cities with annual growth rates three times the average level. Urban expansion within the three capital cities was further analyzed in detail. It is found that outlying expansion and edge-expansion were the dominant growth patterns at all the three levels. Although urbanization in the MYRB has a remarkable increase in the past sixteen years, its annual growth rate of urban land expansion has fallen behind the three other large urban agglomerations in China as a result. Finally, the spatial evolution of the socioeconomic structure of the MYRB was further explored. It indicated that urban land was distributed mainly along the “northwest-southeast” direction and that the economic spatial interactions among cities showed a pattern of “multi-polarization and fragmentation”, which illustrates the weak radiative driving forces of the central cities. The MYRB urban agglomeration faces a great challenge to manage trades-offs between narrowing the intra-regional disparity and maintaining synergetic development among cities.

Land expansion and population growth are the most important factors for urban development in the rapid urbanization stage. Intensive land use is a key goal of urban sustainable development. Therefore, to promote intensive land use, local governments should take the scientific evaluation of the relationship between urban land and population as the basis and make policies cautiously. Thus, it is vital to adopt evaluation methods that are sensitive to intensive land use. However, this topic has received insufficient attention in the literature. Addressing this gap, this study (1) proposes a modified method to evaluate the relationship between land expansion and population growth, (2) compares the results of three evaluation methods, and (3) compares the relationship between evaluation results and urban construction land area per capita (UCAP) using UCAP as an indicator of intensive land use. Our findings indicate that existing evaluation methods do not adequately reflect the state and trend of intensive land use and that our modified model significantly improves the sensitivity to intensive land use. Additionally, this paper provides policy suggestions based on a quantitative evaluation of the relationship between urban land expansion and urban population growth. These conclusions provide a basis for formulating planning strategies to promote the intensive use of land in cities in the stage of rapid development.

Land expansion of mountain cities in China is not systematically studied yet. This study identified 55 major mountain cities at and above prefecture level, and analyzed the land expansion characteristics and driving forces, based on visually interpreted data from TM images in 1990, 2000, 2010 and 2015. From 1990 to 2015, total built-up land area of the mountain cities increased by 3.87 times, 5.56% per year. The urban land growth was apparently accelerated after 2000, from 4.35% per year during 1990–2000 increased to 6.47% during 2000–2010 and 6.2% during 2010–2015. Compared to the urban population growth, the urban land expansion rate was 44% higher. As a result, the urban land area per capita increased, but it was still within the government control target, and also was much lower than the average of all cities in China. Urban development policy, changes to administrative divisions, GDP and population growth, and road construction were identified as the major driving forces of land expansion. Terrain conditions were not found a relevance to the urban land expansion rate during 1990–2015, but had a significant impact on the layout and shape, and also probably on the urban land efficiency.

With the pursuit for global competitiveness and economic growth, Chinese cities have recorded massive urban land expansion. This article examines the effects of development policies and economic restructuring on urban land expansion in China through a case study of Nanjing, representing the rapidly growing and globalizing coastal cities in China. Wei investigate the development process and changing contents of government policies, and analyze development zones and key projects as privileged, trait making, and even path‐breaking elements of the development process. We highlight the transition and paradox of the Chinese state in the urban development process, and the broad contexts underlying urban land expansion in Chinese cities. We see urban expansion in China as a process largely responding to top‐down policy change and economic transition initiated by the central government. We hold that the role of the state has to be analyzed to understand urban transformation and land expansion, moving beyond local factors of accessibility and feasibility. Development‐zone and project fevers, and lagging administrative reforms, however, have made Chinese cities heavy with debt and led to wasteful development, corruption, and social unrest in China.

More profound knowledge about urban land use and expansion is needed to better understand the growth and sustainability of Chinese cities. This special issue is dedicated to addressing land use and environmental issues arising from the urbanization process, and aims to identify and model the mechanisms of land use and environmental changes. It draws from papers that were presented in the sessions titled ‘‘Urbanization, Land Use, and Regional Development in China I, II, III’’ at the Annual Meeting of the Association of American Geographers in New York, February 24–28, 2012. In addition, we have also collected papers presented at the ‘‘International Conference on Urbanization and Development in China’’ held at the University of Utah in Salt Lake City, August 26–28, 2011, and through an open call for papers. Articles published in this special issue have all successfully gone through a very selective and rigorous anonymous peer-review process in order to secure a fairly high standard and a good balance between the different topics, debates, and study regions. This special issue has thus contributed to the broadening of the geographical scope and scale of research. This special issue is situated in the broad trends of academic enquiry on modeling urban growth and land expansion in China. Specifically, this research furthers the study of local variations on urban growth patterns with recently developed geographic information science (GIS) spatial analysis techniques such as geographically weighted logistic regression, and interprets urban growth patterns through the analysis of institutional change and on-theground field experiences. This special issue has also further attempted to incorporate socio-economic variables and expand the coastal cities-based research to interior cities. While the focus of this special issue is urban land expansion, it also explores a wide range of associated topics, including the characteristics of environmental problems and how this is related to China’s urban transition. This issue is a collection of 10 papers selected out of many candidate ones from the two conferences and open call for papers. Due to quality control and space limitation, some of the submitted manuscripts had to be rejected. We thank all those who submitted their abstracts and papers. We greatly appreciate the prompt action from both authors and reviewers, which allowed the timely publication of this special issue. Finally, our thanks also go to Dr. George Christakos, SERRA’s Editor-in-Chief, who helps us achieve the realization of this special issue.

As a developing country, China is experiencing rapid urbanization. With rapid economic development and urban population growth, urban land continues to expand. The urban land expansion provides development space for cities; however, the disorderly expansion of urban land also results in a significant waste of land resources. In order to effectively regulate the scale of urban land and prevent the disorderly expansion of urban land, it is necessary to conduct analyses of the characteristics and trends of urban land expansion. In the present paper, taking Shandong province as the research area, we analyze the characteristics and limits of urban land expansion. Based on the relationship between urban land expansion, economic development, and urban population growth, using urban land area, the output value of secondary and tertiary industries, and population data to construct a marginal effect model and logistic model to estimate the limit time and limit scale of urban land expansion in Shandong province from the perspectives of economic development and urban population growth. The results show that: (a) Economic development and urban population growth are the main influencing factors of urban land expansion in Shandong province. With the development of the economy and urbanization, the expansion rate of urban land in Shandong province is decreasing. (b) From the perspective of economic development, With the continuous improvement of urban land use efficiency, the demand for newly-added urban land by economic development gradually weakens. In 2033, the urban land in Shandong province will reach the expansion limit, with a limit scale of 7982 km2. (c) From the perspective of urban population growth, in 2037, the urbanization rate of Shandong province will reach 80%, the urban population will be stable, and the urban land will reach the expansion limit, with a limit scale of 9068.8 km2.

Relationship between urban construction land expansion and population/economic growth in Liaoning Province, China

Urban land will face high fluvial flood risk against the background of climate change and urban expansion. The effect of urban spatial expansion, instead of densification of assets within existing urban cells, on flood risk has rarely been reported. Here, we project the future flood risk of seven urban agglomerations in China, home to over 750 million people. The inundated urban land areas in the future are projected to be 4 to 19 times that at present. Without considering the urban spatial expansion, the inundated urban land areas will be underestimated by 10-50%. Urban land is more likely to be inundated than non-urban land, and the newly-developed urban land will be inundated more easily than the historical urban land. The results demonstrate the urgency of integrating climate change mitigation, reasonable urban land expansion, and increased flood protection levels to minimize the flood risk in urban land.