Search Results (181)

The research aims to develop methodologies for the detailed characterization and spatial zoning of landfills as a means of assessing their environmental impact. The principal objective is to establish an integrated framework for evaluating landfill conditions through multisource data analysis, encompassing remote sensing, field investigations, and geochemical analyses. The proposed framework incorporates several critical components: satellite and UAV-based remote sensing, multispectral vegetation assessment, geochemical soil profiling, temporal and functional zoning, and morphodynamic evaluation. Research findings indicate substantial environmental pollution in the vicinity of landfill sites, at levels that exceed the natural self-purification capacity of surrounding ecosystems. This encompasses the contamination of all principal environmental components, including groundwater, surface water, soil, vegetation, and atmosphere. The key findings demonstrate that only a comprehensive environmental impact analysis, conducted in conjunction with detailed landfill zoning, yields a thorough understanding of the associated adverse effects. Remote sensing methodologies are shown to play a pivotal role in data acquisition and ongoing monitoring. The practical contribution of this study lies in the development of methodological frameworks for detailed landfill zoning, environmental impact assessment, monitoring, damage mitigation measures, and waste management optimisation. The results obtained have the potential to improve waste management systems, inform the development of effective monitoring protocols, and underpin strategies aimed at reducing the environmental footprint of landfills. Overall, this research advances scientific and technical knowledge in the field of waste management and contributes towards efforts to mitigate environmental impact—a matter of persistent concern given rising rates of waste generation and the increasingly constrained availability of suitable landfill capacity. Full article

Medium-sized cities play an important role in regional settlement systems as intermediary centres linking metropolitan areas with smaller towns and rural regions. Due to their relatively compact spatial structure, such cities are often associated with the principles of the 15-min city concept, which promotes accessibility to key services and public spaces within walking distance. Urban regeneration is an important instrument supporting sustainable development and improving quality of life in these cities. This study examines the relationship between legal regulations, spatial delimitation patterns, and the spatial distribution of degraded and revitalised areas in medium-sized cities. The research is based on a comparative analysis of qualitative and quantitative criteria, GIS-based spatial analyses, and accessibility modelling conducted for five cities in the Pomeranian Voivodeship using planning documents and statistical data, verified through field surveys. The results indicate a high degree of spatial continuity of revitalisation areas despite changes in legal frameworks and delimitation methodologies. Revitalisation areas remained concentrated mainly within historic city centres and their multifunctional surroundings, while degraded areas gradually expanded toward residential districts. The findings also demonstrate a strong spatial relationship between revitalisation areas and 15 min walking accessibility zones. The study provides useful comparative insights for countries developing formal urban regeneration systems. Full article

Amid accelerating global environmental change, assessing ecological vulnerability is critical for sustainability science. Focusing on the Yellow River Source Region (YRSR)—a key water source and ecological shield in China—this study develops an integrated assessment system based on the “Pressure–State–Response” (PSR) framework, incorporating 29 indicators. A combined weighting approach integrating analytic hierarchy process (AHP) with entropy-based objective weighting characterizes the spatiotemporal patterns, drivers, and future trajectories of ecological vulnerability. Key findings reveal: (1) heterogeneous warming–wetting trends with stronger humidification in the south and relative stability in the north drive divergent hydrological responses, highlighting the limitations of single-climate metrics in explaining vulnerability dynamics; (2) vulnerability patterns are primarily shaped by climatic factors—especially temperature and potential evapotranspiration—with anthropogenic pressures serving as secondary modulators, reinforcing the foundational role of thermal and moisture regimes in alpine ecosystem resilience; and (3) scenario projections consistently identify the northeast as a persistently high-vulnerability zone, yet show that balanced socioeconomic development can reconcile ecological protection with development needs. Based on these insights, a four-tier ecological zoning scheme and a governance framework comprising three strategies—strict conservation, adaptive regulation, and sustainable utilization—are proposed. This work offers actionable scientific guidance for tailored ecological conservation in the YRSR and contributes methodological advancements for vulnerability assessment and adaptive management of high-elevation ecosystems globally. Full article

Under climate warming, frequent short-duration extreme precipitation events in coastal megacities exacerbate urban waterlogging, whereas the associated convective mechanisms over complex underlying surfaces remain poorly understood. On 21 July 2023, an extreme short-duration rainfall event (14:00–19:00 LST, peak intensity 127.3 mm h⁻¹) struck Shanghai under weak vertical wind shear (VWS) conditions that cannot be fully explained by classic storm dynamics. Based on multi-source observations, this study shows that the middle and lower troposphere was controlled by warm, moist southwesterly flows, with highly favorable thermodynamic conditions (CAPE ~3300 J kg⁻¹, CIN near zero) that only required weak local lifting to trigger convection. Both 0–1 km and 0–6 km VWS were below 7 m s⁻¹, maintaining stable, upright updrafts that favored high precipitation efficiency. The formation and maintenance of the quasi-linear convective system and the resultant extreme precipitation depended critically on the southerly sea breeze, local mesoscale convergence, and cold pool feedback. Convergence induced by the complex underlying surface (urban friction, high-rise building blocking) played important roles in initiating convective cells, while the interaction between cold pool outflows and the sea breeze from the East China Sea and Hangzhou Bay sustained the system, which evolved into a unique “fish-shaped” rainstorm. Driven by dominant convective propagation toward unstable inland areas, the system moved west–southwestward across the coastal zone into central urban Shanghai. This mechanism differs from both the cold pool–VWS balance under strong shear and the urban convective relay propagation mode under weak VWS documented in previous studies. These findings provide new observational insights into the formation and maintenance of weak-shear, short-duration extreme rainfall in coastal megacities, and carry important implications for identifying convectively prone zones, optimizing spatial development patterns, and improving climate-resilient land management and urban planning practices. Full article

As global climate change intensifies, typhoon disasters pose growing threats to the socio-economic stability of coastal cities. Quantifying urban typhoon resilience and identifying its spatial driving mechanisms are essential for informing targeted disaster risk management and built environment optimization. This study develops an NTL-based framework to quantify urban typhoon resilience across three major typhoon events in Zhuhai from 2017 to 2020, using NTL loss rate and NTL recovery time as the primary resilience indicators and NTL loss as a descriptive measure of absolute disaster impact magnitude. OLS and GWR models are then applied to a 20-factor indicator system to identify the global drivers of resistance and recovery capacity and uncover the spatial heterogeneity of their effects across urbanization gradients, with the aim of providing both a replicable methodological framework and an empirical basis to inform differentiated resilience optimization strategies for coastal cities. The results demonstrate that urban typhoon resilience varies systematically across urbanization gradients in both dimensions. Highly urbanized areas consistently show stronger resistance, with NTL loss rates of 32–46% versus 36–50% in low-urbanized areas, as well as faster recovery, with NTL recovery times of 2.6–3.8 days versus 2.9–5.6 days. Transportation infrastructure emerges as the most consistent global driver. GWR reveals that its effects are most pronounced in less urbanized areas, where the absolute coefficient for transport station density reaches 4.804 (over 4% higher than in other zones). Blue–green infrastructure also plays a significant role, with higher NDVI values being associated with shorter recovery times. These findings provide a replicable NTL-based methodological framework and spatially explicit empirical evidence to support targeted and differentiated resilience optimization in coastal cities. Full article

Linear heritage corridors are increasingly exposed to spatially heterogeneous pressures from climate change and human activities, yet integrated geospatial frameworks for corridor-scale risk identification remain limited. Taking the Beijing–Hangzhou Grand Canal as a representative linear World Heritage corridor, this study developed a GIS-based spatiotemporal assessment framework to quantify natural risk, anthropogenic pressure, and their coupled patterns during 1995–2024. Approximately 350 canal segments were constructed as comparable assessment units and linked with 49 heritage sites and 18 World Heritage canal sections through a multi-scale spatial framework integrating canal sections, buffer zones, and heritage sites. Natural risk was characterized using extreme temperature, precipitation, and drought indices, while anthropogenic pressure was represented by nighttime lights, population density, impervious surface, and road density. The results reveal a clear north–south gradient in integrated natural risk, with higher values concentrated in the southern canal sections. Among the three natural-risk modules, temperature, precipitation, and drought contributed weights of 0.594, 0.242, and 0.164, respectively, indicating the dominant role of heat-related processes. The first two principal components of anthropogenic pressure explained 80.8% of the total variance. Four dominant coupling types were identified, among which the dual high-pressure type was concentrated mainly in the southern canal and marked the most critical areas of compound risk. This study provides a geospatial approach for hotspot detection and spatial decision support for the conservation of large linear heritage systems. Full article

Karst regions are commonly characterized by highly interwoven bare rock–bare soil–vegetation mosaics, strong coupling between surface and subsurface processes, and pronounced geomorphic fragmentation. Conventional land cover classification systems, which are primarily organized around land use patterns or generic ecological types, are often unable to accurately represent these key surface components and their roles in ecological processes. From the perspective of reconstructing classification semantics, this study proposes a Natural-Attribute-Based Karst Land Cover Classification framework (NALCC). The framework takes bare rock, bare soil, vegetation, water bodies, and impervious surfaces as primary classes, and further develops a hierarchical system consisting of subclasses, attribute labels, hierarchical coding, multi-scale organization, and parameter mapping with ecosystem service models. Compared with conventional land cover classification systems, the innovation of this framework lies not in increasing the number of categories, but in reconstructing the semantic organization of classification units, so that land cover classification can move beyond surface-type description toward the expression of process-sensitive information. The classification objective of NALCC is not to develop a universal land cover classification system, but to establish a process-oriented classification framework for ecosystem service monitoring, rocky desertification diagnosis, and governance zoning in karst regions, which can directly represent key surface components and their ecological-process significance. However, its regional transferability and mapping performance still need to be further validated through case studies in representative areas. Full article

As one of the three major bays in the Chinese Bohai Sea, Bohai Bay is located in a semi-encircled area consisting of three important provinces and cities with rich energy and fishery resources. The bay is not only a maritime gateway and transportation hub but also an important industrial base, energy production base, and port. In this study, we combined Landsat remote sensing and Geographic Information System technologies to extract the coastline of Bohai Bay from 2001 to 2021 and obtained the variation in coastline length by refinement vector processing. Sediment as the natural driver was quantitatively analyzed based on sand transport in the Yellow River and Hai River. Moreover, port construction was qualitatively analyzed as the anthropogenic driver. The results demonstrated that the coastline of Bohai Bay showed an overall growth trend in this period, with a total increase of 881.05 km in shoreline length; the main increase was in the artificial shoreline. The two natural driving factors, sediment and hydrodynamic conditions, were weak, and the anthropogenic driving factor, i.e., various human activities, played a dominant role in the variation in the Bohai Bay shoreline in the past 20 years. The extracted shoreline information is important not only for the rational and effective development and utilization of the various natural resources in the coastal zone of Bohai Bay but also for the plan to develop this important region in the future. Full article

Efficient storm drainage systems (SDSs) play a pivotal role in sustainable urban development. In arid regions, urban SDS often underperform during prolonged dry periods, leaving them inoperable due to sediment buildup and clogging from the intrusion of sprawling waste. Municipalities either rely on emergency response to flooding complaints or inspect storm sewers individually to handle flash floods and conserve high-value rainwater. The present study developed a risk-based decision-analysis framework for resource-efficient inspection and maintenance (I&M) planning of SDS to prioritize geographically clustered sub-zones. The study applied the framework to a case study of three urban zones with varying population densities and land use distributions in Buraydah, Qassim, Saudi Arabia. The framework integrates fuzzy synthetic evaluation (FSE) to address data limitations and subjective expert knowledge, with geographic information system (GIS)-based spatial analysis to assess three risk factors: likelihood, consequences, and detectability of sewer clogging potential. In addition to traditional likelihood-based evaluation of the susceptibility of smaller sewers to sediment accumulation due to performance anomalies, the consequence analysis augmented the process by considering land-use characteristics, exemplified by commercial areas exhibiting higher socio-economic losses than open spaces that buffer excess runoff. The detectability factor consolidated the decision analysis by incorporating the impacts of past delayed inspections, deep manholes, and scattered construction-related waste on clogging potential. The analysis identified sub-zones with aged sewers, deep manholes, long-awaited inspections, and high population densities, resulting in a high risk. GIS maps showing distinct impacts of the three factors on overall flood risk facilitate municipalities facing unique urban flooding challenges arising from sediment accumulation during long dry periods, followed by short-duration, high-intensity rainfall. Full article

This study extends beyond traditional single-binder assessments by developing a mechanistic framework for interpreting the behavior of multi-component geopolymer systems. It systematically examines the roles of industrial by-products (granulated blast-furnace slag), agricultural residues (barley straw ash), and construction-derived materials (recycled granite powder) when integrated into a metakaolin-based matrix, with particular emphasis on their influence on gel formation pathways, microstructural refinement, and macroscopic performance. A sustainable geopolymer concrete (SGC) system was formulated using multi-binder combinations at replacement levels ranging from 5% to 30%. Comprehensive evaluations were conducted, including fresh properties, mechanical performance, durability characteristics, thermal resistance, and microstructural features. The results demonstrate that the 70Mk–30GBFS composition facilitates the development of a dense hybrid C–(A)–S–H/N–A–S–H gel network, resulting in a 26.8% enhancement in compressive strength and a 32.0% decrease in chloride ion penetration. Rather than depending on empirical relationships, the study establishes a mechanistically grounded link between precursor chemistry, interfacial transition zone (ITZ) refinement, and performance limits. These findings contribute to a deeper understanding of multi-component geopolymer design and support the development of high-performance, sustainable concrete materials for structural applications. Full article

Against the background of ecological civilization construction and the transformation of state-owned forest regions after the logging ban, balancing economic development with ecological protection has become an important issue in China’s forest areas. The development of the non-timber forest-based economy plays a critical role in advancing high-quality, green economic growth in China and contributes significantly to sustainable resource utilization. This study examines data from key state-owned forests and the natural environment in the Changbai Mountain region of Jilin Province from 2013 to 2023. A comprehensive evaluation model and a coupling coordination model, based on the human–land relationship framework, are employed to assess temporal changes in economic growth quality, ecological environment carrying capacity, and their coupling coordination. The quality of non-timber forest-based economic growth exhibited an overall upward trend. Fusong County, Wangqing County, and Dunhua City consistently maintained high levels, while Helong City experienced the largest decline. The spatial distribution followed a “high center, low periphery” pattern, with the 2015 logging ban serving as a key turning point in promoting ecological transformation. The per capita ecological environment carrying capacity improved across the region, with significant increases in Dunhua, Helong, and Antu Counties. A radial decline from the central to peripheral areas was observed, with the highest values in Wangqing and Antu Counties. The coupling coordination degree between economic growth and ecological environment fluctuated between 0.4 and 0.6. In 2023, Wangqing County reached a state of intermediate coordination (index > 0.7), whereas Linjiang remained in a dysfunctional state (index < 0.5). Spatial clustering of coordination weakened over time, as indicated by Moran’s I values of 0.32, 0.21, and 0.09 in 2013, 2018, and 2023, respectively. These findings provide a quantitative foundation for promoting the coordinated development of human–land systems and guiding high-quality regional growth in forest-based economic zones. Full article

This paper investigates the strategic zone design problem for a bus-based passenger–parcel sharing delivery system. In the envisioned system, parcels are first transported along an existing bus line and transshipped at bus stops, after which dedicated vehicles perform last-mile deliveries from bus stops to customers. By leveraging the underutilized capacity of existing bus services to support parcel distribution, the system contributes to a more resource-efficient and less truck-dependent urban logistics structure, thereby supporting sustainability in urban transportation. The problem is to partition the corridor-level service area into multiple contiguous service zones along the corridor under an m-nearest feasibility requirement. A nonlinear integer programming model is developed that jointly captures parcel and passenger perspectives. On the parcel side, the objective combines zone compactness, parcel-demand balance, and parcel-delivery-distance balance; on the passenger side, it minimizes passenger impact. In this way, the model balances logistics efficiency with social-equity and service-quality considerations and operationalizes sustainability through measurable planning indicators embedded in the objective function. A tailored adaptive large neighborhood search algorithm is proposed to exploit the specific problem structure and solve the model. Case studies based on a real-world bus line in Yancheng, China, illustrate the effectiveness of the proposed method and yield managerial insights into the choice of the number of zones, the influence of passenger-flow patterns, and the role of objective-function weights in shaping trade-offs between parcel delivery efficiency and equity, as well as passenger service quality. Full article

Understanding the long-term dynamics of cropland water use efficiency (WUE) and its underlying environmental drivers is essential for ensuring food and water security, particularly for regions facing intensified climate change. Here, we investigated the spatial patterns and long-term trends of gross primary productivity (GPP), evapotranspiration (ET), and WUE in cropland ecosystems across Northeast China during the past two decades as the nation’s primary commodity grain base using the time-series Breathing Earth System Simulator (BESS) products. Subsequently, the ridge regression method was used to quantitatively disentangle the relative contributions of key climatic variables to the observed WUE trends of cropland. Our results revealed a pronounced decreasing gradient in both GPP and ET along the southeast–northwest direction. A significant increase in GPP was observed over the 20-year period (p < 0.01), with 95.94% of the cropland area showing positive trends. ET showed a slight, non-significant increase (p > 0.05), though 82.77% of pixels exhibited positive trends, particularly in the northwest. Consequently, WUE showed a widespread and significant enhancement (p < 0.01), with approximately 98% of cropland pixels exhibiting increasing trends. Attribution analysis identified air temperature as the dominant environmental variable, accounting for 92.4% of the observed WUE increase, while solar radiation and precipitation contributed modestly (3.4% and 3.2%, respectively). Our findings underscore the predominant role of thermal conditions in shaping the carbon–water coupling efficiency of agroecosystems in semi-arid to semi-humid transition zones. This study provides quantitative evidence that warming climate, rather than changes in water availability or radiation, has been the primary climatic factor driving the improved cropland WUE over the past two decades. These insights have important implications for developing adaptive water management strategies to enhance agricultural climate resilience in Northeast China and similar regions worldwide. Full article

Fine-scale accounting of land use carbon budgets and identification of their driving factors provides an essential scientific basis for constructing green and low-carbon territorial spatial systems. This is of great significance for optimizing territorial spatial structure and promoting low-carbon development in urban agglomerations. Taking the Central Guizhou Urban Agglomeration as the study area, this study employed a composite carbon coefficient method to construct a 30 m × 30 m grid-based carbon budget index and quantitatively assessed carbon budget changes induced by land use transitions from 2000 to 2024. POI data and a quantile regression model were further integrated to analyze the dominant spatial characteristics associated with carbon budgets, and a carbon budget monitoring and early-warning index was developed to delineate risk zones. The results show that: (1) From 2000 to 2024, the total area of land use change reached 0.95 × 10⁴ km² in the Central Guizhou Urban Agglomeration, accounting for 17.68% of the total land area, and leading to a net increase of 2.3821 million tons of carbon emissions. This increase was primarily associated with the conversion of cultivated land to construction land, with an accelerated growth rate observed in the later period. (2) The spatial patterns of carbon budgets and carbon emission risk levels exhibit a distinct “core–periphery” structure, with high carbon emission levels concentrated in built-up urban areas and lower levels observed in peripheral ecological land. (3) The expansion of construction land is the dominant contributor to the increase in net carbon emissions; industrial, transportation, and residential spaces exert significant positive driving effects, whereas commercial and service spaces show a negative association. (4) Carbon budget risk zoning based on dominant spatial characteristics identifies Guiyang and Anshun as extremely high-risk areas. The results further suggest that reducing carbon-increment spaces and increasing carbon-reduction spaces may play an important role in territorial carbon budget optimization. The integrated “accounting–driving–monitoring” analytical framework established in this study provides a scientific basis for territorial spatial optimization and carbon emission reduction in mountainous urban agglomerations. Full article

Improving urban land use efficiency is a critical pathway toward sustainable urban development, particularly in large countries undergoing rapid urbanization such as China. However, significant disparities in land use efficiency exist across cities, largely due to differences in economic development, resource endowments, and governance practices. These disparities highlight the necessity of conducting a systematic spatiotemporal assessment of land use mismatch at the city level to identify regional weaknesses and inform differentiated policy mechanisms. This study extends the land use mismatch (LUM) model, which introduces a supply–demand framework for analyzing the mismatch phenomenon of urban land use. Building on the LUM model, this study innovatively develops a classification system of five mismatch zones across eight construction land types, which provides a more systematic and comprehensive approach to identifying land use mismatch patterns. The empirical analysis is conducted using data from 283 prefecture-level cities in China. The results reveal substantial spatial heterogeneity in land use mismatch across Chinese cities. Most of the cities in East China generally fall within acceptable mismatch zones, where market mechanisms play a more effective role in land allocation. Cities in Western China exhibit more serious mismatch levels, where policy intervention seems more significant in land use planning. Cities in Central China demonstrate mixed patterns, ranging from acceptable to severe mismatch. The findings further indicate that these disparities are associated not only with economic and geographical differences but also with variations in governance practices, particularly the interaction between policy intervention and market mechanisms. This study introduces a new approach to examining the patterns of land use mismatch and provides evidence-based policy recommendations for cities in different regions to reduce land mismatch and promote more efficient use of urban land. Full article