The U-Chang-Shi (Urumqi-Changji-Shihezi) urban cluster, located at the heart of Xinjiang, boasts abundant natural resources. Over the past two decades, rapid urbanization, industrialization, and climate change have significantly threatened the region\'s ecological livability. To comprehensively, scientifically, and objectively assess the ecological livability of this area, this study leverages the Google Earth Engine (GEE) platform and multi-source remote sensing data to develop a comprehensive evaluation metric: the Remote Sensing Ecological Livability Index (RSELI). This aims to examine the changes in the ecological livability of the U-Chang-Shi urban cluster from 2000 to 2020. The findings show that despite some annual improvements, the overall trend in ecological livability is declining, indicating that the swift pace of urbanization and industrialization has placed considerable pressure on the region\'s ecological environment. Land use changes, driven by urban expansion and the growth in agricultural and industrial lands, have progressively encroached upon existing green spaces and water bodies, further deteriorating the ecological environment. Additionally, the region\'s topographical features have influenced its ecological livability; large terrain fluctuations have made soil erosion and geological disasters common. Despite the central plains\' vast rivers providing ample water resources, over exploitation and ill-conceived hydrological constructions have led to escalating water scarcity. The area near the Gurbantunggut Desert in the north, with its extremely fragile ecological environment, has long been unsuitable for habitation. This study provides a crucial scientific basis for the future development of the U-Chang-Shi urban cluster and hopes to offer theoretical support and practical guidance for the sustainable development and ecological improvement of the region.

Urban expansion has been rapidly increasing and is projected to be tripled in 2030 in worldwide. The impact of urbanization has adverse effects on the environment and economic development. Residential lands consist of almost one-third of the urban area and heavily affect the city\'s inhabitants. The capital of Mongolia, Ulaanbaatar, has been significantly expanded, particularly in the urban periphery where poor living conditions and a lack of essential urban services were identified. The paper aims to conduct a suitability analysis of residential areas in Ulaanbaatar city based on three main categories (livability, affordability, and accessibility) of fifteen criteria using the fuzzy logic. Through the study, we have identified some potential suitable residential areas for further development, such as apartment residential area located in the southern part of the city and four low-rise ger areas were distributed along major transport corridors. Moreover, the results indicated that the spatial structure of the whole town might be in transition to a polycentric pattern. However, a concentric ring pattern in the \'city\'s periphery displayed a concerning uncontrolled ger area expansion, which may increase low living conditions in the area. This study recommends better urban sprawl control policies and more property market investment in the ger area to ensure sustainable development goals in Ulaanbaatar.

The urban heat island (UHI) effect has become increasingly prevalent and significant with the accelerated pace of urbanization, posing challenges for urban planners and policymakers. To reveal the spatiotemporal variations of the urban heat island effect in Jinan City, this study utilized Landsat satellite images from 2009, 2014, and 2019, employing the classic Mono-Window algorithm to extract land surface temperature (LST). Additionally, Geodetector was introduced to conduct a detailed analysis of the relationship between LST in Jinan City and land cover types (vegetation, water bodies, and buildings). The results indicate a significant increase in the severity of the urban heat island effect in Jinan from 2009 to 2019, with the central urban area consistently exhibiting a high-intensity core heat island. Suburban areas of Jinan show a clear trend of merging their heat island effects with the central urban area. The combined area of strong cool island effect zones and cool island effect zones within water bodies reaches 89.7%, while the combined proportion of heat island and strong heat island effect zones in building areas is 62.2%. Vegetation cover (FVC) exerts the greatest influence among all factors on the intensity level of the urban heat island effect. These findings provide a reliable basis for decision-making related to urban planning and construction in Jinan City.

Understanding the characteristics of waterlogging in urban agglomeration is essential for effective waterlogging prevention and management, as well as for promoting sustainable urban development. Previous studies have predominantly focused on the driving mechanisms of waterlogging in urban agglomeration at a single scale, but urban agglomeration space has greater spatio-temporal heterogeneity, it is often difficult to fully reveal such characteristics at a single scale. Consequently, this study endeavors to explore the spatio-temporal evolution characteristics and underlying mechanisms of waterlogging incidents within urban agglomerations by adopting a multi-scale analytical approach. The results indicate that: (1) The waterlogging degree and high-density zones increase in the GBA, and the waterlogging points are spatially polycentric. However, the waterlogging point in Hong Kong is decreasing. (2) The influence of ISP and AI on waterlogging is dominant at all scales, followed by RE and Slope. ISP∩Slope and ISP∩RE are the key interactions for waterlogging. (3) The aggregation of waterlogging decreases with grid scale, and the influence of land cover factors on waterlogging increases with grid scale. Moreover, the findings at the grid scale outperformed those at the watershed scale, indicating that the grid scale is more conducive to the investigation of waterlogging in urban agglomerations. This research broadens our comprehension of the mechanisms behind waterlogging in urban agglomeration and provide references for policy decisions on waterlogging prevention and mitigation within urban agglomerations.

For the sustainable development of the city, in a study of Tianjin\'s rapid urbanization, we explore the complex interplay between land use change and the ecosystem carbon cycle from 2000 to 2020. Spatial analysis and profit-loss matrix calculations reveal contrasting ecological impacts: expansion of woodlands and grasslands enhances Net Primary Productivity (NPP) and reduces carbon emissions, while urban construction shows the opposite effect. Over 20 years, Tianjin\'s urban transformation led to a 16.91 GgC decline in NPP amidst a construction boom. However, post-2015 ecological policy shifts resulted in a significant net carbon uptake of 0.85 Gt, demonstrating the potential of policy interventions in mitigating environmental impacts of urbanization. This study underscores the importance of sustainable urban planning and ecological conservation strategies in highly urbanized settings.

Evaluating the sustainable development level and obstacle factors of small towns is an important guarantee for implementing China\'s new-type urbanization and rural revitalization strategies, and is also a key path to promoting the United Nations Sustainable Development Goal 11 (SDG11). Traditional evaluation methods (such as Analytic Hierarchy Process, AHP, and Technique for Order Preference by Similarity to Ideal Solution, TOPSIS) mainly calculate the comprehensive score of each indicator through weighting. These methods have limitations in handling multidimensional data and system nonlinearity, and they cannot fully reveal the complex relationships and interactions within the sustainability systems of small towns. In contrast, the evaluation model combining Principal Component Analysis (PCA) and Catastrophe Progression Method (CPM) used in this study can better handle multidimensional data and system nonlinear relationships, reducing subjectivity in evaluation and improving the accuracy and reliability of the assessment results. The specific research process is as follows: First, based on the United Nations SDG11 framework, using multi-source big data, a theoretical framework and evaluation index system for the sustainable development of small towns suitable for the Chinese context were established. The impact of county-level factors on the sustainable development of small towns was also considered, and an entropy weight-grey correlation model was used to measure these impacts, resulting in a town-level dataset incorporating county-level influences. Secondly, the sustainability levels of 782 top small towns in China were evaluated using the comprehensive evaluation model based on PCA-CPM Model. Finally, an improved diagnostic model was used to identify obstacles influencing the sustainable development of small towns. The main findings include: 52.69% of the small towns have a sustainable development score exceeding 0.7255, indicating that the overall performance of small towns is at a medium to high development level. The development of small towns exhibits significant differences across regions and types, which are closely linked to county-level effects. Economic and social factors are the main obstacles to the sustainable development of small towns, and the impact of these obstacles intensifies from the eastern to the central, western, and northeastern regions. This study provides valuable insights for policymakers and scholars, promoting a deeper understanding of the sustainable development of small towns.

The rapid urbanization taking place in Africa is resulting in the emergence of large urban agglomerations. Despite the potential and typical economic benefits associated with the emergence of such agglomerations elsewhere, not much can be said of Africa\'s urbanization. With urbanization projections pointing to a continued increase, there is a need to understand the urbanization and economic dynamics relationship in order to exploit the full potential of this wave. Using a panel data set of urbanization rate, trade, economic growth, productivity and employment in six African countries for the period 1991-2019, we explore this relationship by adopting the cross-sectional augmented autoregressive distributed lag (CS-ARDL) approach using data from six African countries. The findings show that there is a significant relationship between urbanization, international trade, economic growth, productivity, and employment. they also show a causal relationship between the variables studied. In addition, the findings of this study reveal that international trade contributes, significantly, to improving the productivity in long run and the economic growth and employment increase the productivity in short run and employment in the selected African countries. This research study, therefore, contributes to the critical argument that African urbanization and international trade have significant economic potential and therefore need to be encouraged and managed effectively. This provides evidence for planners and policy-makers to back policy geared toward sustainable urbanization and diversified international trade that will contribute to the structural transformation of African countries.

This study explores the conservation of historic flyway corridors for egret in the Greater Bay Area (GBA), with a focus on habitat connectivity and dynamic corridors. To address the gaps in previous research, we used field observations, bio-climatic data and landcover information spanning three decades. Our approach involves MaxENT modeling and the Linkage Mapper method. The results showed that the MaxENT model effectively simulated the egret habitats at different levels, with coastlines and riverbanks emerging as primary habitat zones. Moreover, bio-climatic factors, particularly Bio 19 and Bio 8, played a dominant role, accounting for 90 % of the habitat suitability in 2020. Other factors contributed rather minimally. Through the utilization of resistance surface and corridor extraction methods, noteworthy alterations in the flyway networks emerged post-2000, followed by a gradual return to normal. Connectivity analyses highlighted a critical 30 km threshold for the egret preservation. Corridor widths should be determined based on cost-effective considerations. We conclude that combining MaxENT with the Linkage Mapper method, even with limited egret observations and integrating multi-source data, such as land cover, might simulate potential suitable habitats and flyway dynamics for waterbirds such as egrets. This study provides valuable insights for the egret conservation and the preservation of their habitats in the GBA, contributing to a global waterbird diversity and habitat quality.

The continuous expansion of modern cities not only leads to ecological degradation but also seriously threatens regional ecological security and sustainable development. The construction of ecological security patterns (ESPs) has emerged as a significant approach to alleviate or even solve the conflict between regional development and ecological protection. The Chengdu-Chongqing Economic Circle (CCEC) represents the core area of regional economic development strategy in western China, characterized by rapid economic growth from 2000 to 2020. This study integrates assessments of ecosystem services importance, eco-environmental sensitivity and landscape connectivity; uses circuit theory and hydrological analysis to establish a research framework for the spatiotemporal evolution of regional ESP; and develops an optimized ESP combined with the Major Function Oriented Zone. The results indicate that urban expansion significantly impacted the ESP of the CCEC between 2000 and 2020. The fragmentation and merging of ecological sources occurred simultaneously, the number of patches reduced by 28.13% from 64 to 46. The early ecological security network was compromised, leading to the disappearance or elongation of some ecological corridors. The number of ecological corridors decreased by 36.03% from 136 to 87; the total length was reduced by 29.92% from 7500.57 km to 5256.28 km. Urgent optimization of the ESP is needed, reducing the number of key ecological protection areas by 50% from 106 to 53 while increasing priority restoration areas by 13.51% from 37 to 42. The study also reveals the insufficiency of the current Major Function Oriented Zone in protecting linear corridors, necessitating focused attention on the protection and restoration of ecological sources and surrounding corridors in important development zones. Additionally, a spatial optimization strategy of \"one shelter, two cores, and three regions\" is proposed to enhance regional ecosystem stability and connectivity. The aim was to strike a balance between ecological protection and food security by recommending an ecological corridor width range of 30∼100 m. These research findings offer scientific guidance for ecological space protection and restoration in the CCEC, contributing to the enhancement of both scientific and rational ecological planning in rapidly urbanizing areas.

Exploring the spatiotemporal dynamic evolution of local climate zones (LCZ) associated with changes in land surface temperature (LST) can help urban planners deeply understand urban climate. Firstly, we monitored the evolution of 3D urban spatial form in Chengdu City, Sichuan Province, China from 2010 to 2020, used the ordinary least squares model to fit the dynamic correlation (DR) between the changes in urban spatial patterns and changes in LST, and revealed the changes of urban spatial patterns closely related to the rise in LST. Secondly, the spatiotemporal patterns of LST were examined by the integration of the Space-Time Cube model and emerging hotspot analysis. Finally, a prediction model based on curve fitting and random forest was integrated to simulate the LST of study area in 2025. Results show the following: the evolution of the urban spatial form consists of three stages: initial incremental expansion, midterm incremental expansion and stock renewal, and late stock renewal and ecological transformation. The influence of the built environment on the rise of LST is greater than that of the natural environment, and the building density has a greater effect than the building height. The overall LST shows a warming trend, and the seven identified LST spatiotemporal patterns are dominated by oscillating and new hotspots patterns, accounting for 51.99 and 11.44% of the study area, respectively. The DR between urban spatial form and LST varies across different time periods and built environment types, whereas the natural environment is always positively correlated with LST. The thermal environment of the city will warm up in the future, and the area affected by the heat island will shift to the central of the city.