Search Results (1,025)

Rapid urban expansion in arid intermediate cities often produces fragmented urban structures that exacerbate inequalities in public transport accessibility and hinder sustainable mobility. However, the relationships between urban fragmentation, transport accessibility, and travel behavior remain insufficiently explored in pre-Saharan cities. This study investigates these interactions through the case of El Bayadh, Algeria, using an integrated methodology combining urban morphological analysis, Geographic Information Systems (GIS), a household survey of 577 households, traffic counts, institutional interviews, and spatial equality assessment based on the Gini coefficient. Public transport accessibility was evaluated using a 300 m walking threshold, complemented by sensitivity analyses at 400 m and 500 m. The results indicate that approximately 65% of the population lives within 300 m of a bus stop, although coverage is strongly concentrated in central districts. A Gini coefficient of 0.41, provided by the El Bayadh Directorate of Transport and computed across 20 urban zones, indicates moderate-to-high spatial inequalities in accessibility that persist despite increasing the service threshold, suggesting that these disparities are more closely associated with urban fragmentation than with the specific walking-distance threshold used to define service coverage. The transport network comprises 11 bus routes, approximately 160 bus stops, and 90 km of routes; however, limited service quality and uneven spatial distribution contribute to a high dependence on private transport, with 45% of trips made by private car, 35% by taxi, and only 20% by bus. These findings are consistent with accessibility inequalities arising from the mismatch between fragmented urban morphology, centralized urban functions, and the configuration of the public transport network. The proposed framework provides transferable insights for planning more equitable and sustainable mobility systems in rapidly urbanizing arid intermediate cities. Full article

Land-use transformation driven by large-scale water conservancy projects profoundly reshapes regional ecosystem structures and the supply capacity of ecosystem services, yet targeted quantitative assessments linking land-use evolution to ecosystem service values (ESV) in the Xiaolangdi Reservoir resettlement zone remain insufficient, restricting scientific ecological management and territorial spatial governance for reservoir-affected counties and districts. This study draws on the latest ecosystem service valuation theories proposed by domestic and international scholars and applies the value equivalence method to quantify variations in land-use pattern changes and ESV across nine resettlement counties and districts (including the Sanmenxia urban area) affected by the Xiaolangdi Reservoir relocation project. Data collected included historical records (1995–2020), digital elevation models (DEM, 30 m resolution), and land-use information. By applying value equivalence theory and analyzing land-use change impacts, the study calculated changes in ESV and conducted sensitivity analyses across different land types. The findings reveal significant impacts on surrounding counties following the reservoir’s completion. Data indicate that the expansion of water areas drove the total ESV to rise from US$3.3261 billion in 1995 to a peak of US$3.6557 billion in 2010, followed by a decline to US$3.6128 billion in 2020. The most pronounced changes occurred during the first five years post-reservoir filling (2000–2005), marked by elevated water sensitivity indices. This research clarifies the differentiated responses of ecosystem service functions to land-use changes across reservoir-affected counties, provides quantitative decision-making support for coordinated ecological restoration, cultivated land protection, and sustainable land management in the resettlement area of the Xiaolangdi Reservoir, and offers a replicable technical framework for ecosystem service valuation of large sediment-laden river reservoir regions worldwide. Full article

This study assessed the current status of irrigation systems and water management practices in Rwanda’s irrigated agricultural zones, focusing on the Nasho Government-Funded Irrigation (GFI) scheme in Kirehe District and the Kagitumba Irrigation Scheme in Nyagatare District. A mixed descriptive approach was used, combining field observations with structured questionnaires administered via KoboToolbox to 224 respondents in Nasho and 188 in Kagitumba. Field observations were used to evaluate the physical condition and functionality of irrigation infrastructure, while questionnaires captured stakeholder perceptions, water management practices, institutional arrangements, and operational challenges. Results show that both irrigation schemes are operational but function below optimal efficiency due to multiple constraints. In Nasho, irrigation performance is primarily affected by sedimentation in canals and reservoirs, pump inefficiencies, and inadequate maintenance practices, resulting in unreliable water delivery. In Kagitumba, despite the use of modern center pivot systems, performance is constrained by pipeline corrosion, pressure losses, sediment-laden water, and uneven water distribution. Across both schemes, more than 80% of respondents reported frequent system failures, while over 95% indicated the absence of formal irrigation scheduling practices. Water management remains largely reactive, with limited preventive maintenance and weak technical capacity among users and institutions. The study concludes that improving irrigation efficiency in Rwanda requires integrated interventions that combine infrastructure rehabilitation, strengthened maintenance systems, improved water governance, and farmer capacity development to enhance sustainable water use and agricultural productivity. Full article

Land use and land cover (LULC) dynamics are critical indicators of environmental transformation and anthropogenic pressure on regional landscapes. Mirzapur, located in the transitional zone between the Indo-Gangetic Plain and the Vindhyan uplands in Northern India, represents a region characterized by ecological sensitivity, mineral-based industries, agricultural dependency, and rapid infrastructural growth. In recent decades, Northern India has experienced accelerated urbanization, population pressure, land fragmentation, and environmental stress, thus making systematic LULC monitoring crucial for sustainable resource management and policy planning. The present study examines the spatio-temporal changes in land use and land cover in Mirzapur for the years 2004, 2014, and 2024. The study employed a cloud-based platform and the Random Forest algorithm for supervised classification of multi-temporal satellite imagery. LULC maps were generated and post classification comparison was used to assess changes across the selected years. Accuracy assessment was conducted using standard validation metrics, including the Kappa coefficient, to evaluate classification. From 2004 to 2024, urban areas expanded by a relative increase of 169.36%, largely through the conversion of cropland, although the overall cropland area showed a slight increase due to agricultural expansion in other parts of the study area. A slight increase in forest cover was also observed during this period. Water bodies and barren lands declined, indicating ecological stress in the region. These changes reflect rapid urbanization, demographic pressure, and evolving socio-economic activities within the district. The LULC classification achieved overall accuracies of 96.50% (2004), 97.52% (2014), and 96.08% (2024), showing the reliability of the generated maps. The study demonstrates the effectiveness of cloud-based geospatial analysis combined with a machine learning algorithms for long-term LULC monitoring and provides valuable insights for sustainable land management and regional planning. Full article

Historic urban manufacturing territories are increasingly being reconsidered as strategic components of metropolitan sustainability rather than obsolete remnants of industrial economies slated for redevelopment. While these districts have long been associated with pollution, environmental degradation, and post-industrial decline, growing interest in circular economy strategies, Urban Resource Recovery (URR), and climate adaptation has renewed attention to their territorial significance. Using the North Brooklyn Industrial Business Zone and the Newtown Creek watershed as a case study, this paper argues that certain historic manufacturing territories possess an inherent capacity to evolve into Metropolitan Metabolic Infrastructure because of inherited geographic, infrastructural, and institutional characteristics, including waterfront access, freight networks, industrial zoning, large industrial parcels, and utility systems. Drawing upon research developed through the New York City Department of Design and Construction’s Town+Gown Urban Resource Recovery Working Group, the study combines historical analysis, spatial interpretation, planning policy, and case-study research to examine the evolving relationship among urban metabolism, circular economy, environmental justice, and Healthy Cities. Rather than advocating industrial preservation irrespective of environmental performance, the paper argues that these territories can support metropolitan material circulation while advancing cleaner industrial practices, environmental remediation, and more equitable urban development. The Metropolitan Metabolic Infrastructure framework offers a planning perspective for understanding how inherited manufacturing landscapes may contribute to resilient, circular, and healthier metropolitan regions while informing future comparative research on industrial territories undergoing similar transitions worldwide. Full article

Urban expansion generates habitat fragmentation, light pollution, and vegetation loss, driving biodiversity decline globally. Insectivorous bats are particularly suited to track these changes: their taxonomic and functional diversity, combined with their differential sensitivity to landscape configuration and roost availability, makes them reliable bioindicators of urbanization impacts. This study characterized bat acoustic diversity and community composition along an urban–rural gradient in Tacna, Peru, using passive acoustic monitoring. Twenty-three stations equipped with autonomous ultrasonic recorders were established between December 2024 and April 2025. Sonotype identification was validated through linear discriminant analysis (DFA), achieving 94.47% accuracy by Leave-One-Out Cross-Validation (LOOCV). Nine sonotypes were identified, seven Molossidae and two Vespertilionidae; Myotis atacamensis showed the highest detection frequency across all districts. Diversity indices were highest in the peri-urban zone of Pocollay (S = 8; H′ = 1.664) and lowest in Gregorio Albarracín (S = 4; H′ = 0.964). The high dissimilarity between Pachía and the urban core of Tacna (BC = 0.817) points to marked compositional differences linked to urbanization intensity. Records of Nyctinomops laticaudatus and N. macrotis constitute the first documentation for the urban area of Tacna. These results suggest urban and peri-urban sectors may function as ecological oases for bat sonotypes within a hyperarid matrix, providing a baseline for evaluating the role of green spaces, landscape connectivity, and artificial lighting in arid cities. Full article

Groundwater depth is a key control on soil salinization in arid irrigation districts, but seasonal groundwater depth thresholds for different salinization risks remain poorly constrained. Here, we examined the Yichang irrigation area of the Hetao Irrigation District using groundwater depth observations and 0–60 cm soil salinity samples collected before spring irrigation and during the crop-growing season. Indicator Kriging was used to map threshold-based probability zones for groundwater depth and soil salinity in the 0–60 cm root zone; soil salinity thresholds of 2 and 3 g kg⁻¹ represented light-or-higher and moderate-or-higher salinization, respectively, and high-probability matching rates were used to identify the corresponding critical groundwater depths. Groundwater depth showed moderate spatial variability in both seasons, whereas soil salt content showed strong spatial variability. The critical groundwater depths for light and moderate salinization were 2.6 and 2.2 m before spring irrigation and 2.2 and 1.8 m during the growing season, respectively. Soil salt content in the 0–20, 20–40, 40–60 and 0–60 cm layers decreased with increasing groundwater depth, with the 0–60 cm layer well described by an exponential response function. These findings provide a spatially explicit basis for seasonal groundwater regulation, salinization risk zoning and field-scale water–salt management in arid irrigation districts. Full article

Limpopo Province is one of South Africa’s major potato-producing regions, yet the field-level composition and community structure of plant-parasitic nematodes (PPNs) remain insufficiently documented. This study surveyed 30 potato fields in four districts to determine the occurrence, abundance and district-level patterns of PPN genera and to identify whether any detected genera had recognised plant-virus vector relevance. Composite root-zone soil samples were collected during autumn 2019. Nematodes were extracted from 250 cm³ soil subsamples, and PPNs were identified to genus level. Data included PPN, total nematodes, plant-parasitic percentage (PPP), fungal-feeder, bacterial-feeder, Wasilewska Index and Nematode Channel Ratio values. Ten plant-parasitic genera were detected in 25 of 30 fields (83.3%). Meloidogyne had the greatest mean density and prominence value, while Meloidogyne and Helicotylenchus were the most frequent genera. Waterberg had the highest median PPP and the lowest median WI, indicating dominance of PPN in the sampled fields. A virus-vector assessment showed that Nanidorus was the only detected genus that belongs to a nematode family with recognised tobravirus-vector potential. The findings provide an improved baseline for nematode surveillance in Limpopo potato fields and indicate that future monitoring should combine genus- and species-level nematode diagnostics with virus testing where Nanidorus or other trichodorids are detected. Full article

India faces large, persistent yield gaps across eight major crops—wheat, rice, maize, soybean, pulses, mustard, cotton, and sugarcane—that collectively limit food security and rural income. This review synthesises evidence from over 100 peer-reviewed studies (1990–2024) to provide the first comprehensive, multi-crop, agro-climatically resolved yield gap analysis for India. Applying the three-tier framework of potential yield ($Y_p$), attainable yield ($Y_a$), and farmer yield ($Y_f$), exploitable yield gaps are quantified at national and agro-climatic zone level, ranked limiting factors are identified, and projected climate change impacts are assessed. Yield gaps range from 20 to 35% in irrigated rice of the north-western Indo-Gangetic Plain to 60–75% in rainfed cotton and pulses of the semi-arid tropics. Yield gaps of blackgram across 20 major districts average 515 kg ha⁻¹, driven by moisture stress, biotic pressure, and management constraints. Nitrogen management, irrigation access, variety adoption, and sowing-date optimisation collectively explain 80–85% of exploitable gaps, while nitrogen and irrigation alone account for 40–58%. Closing 50% of exploitable yield gaps could add approximately 100 million tonnes of food grain annually without expanding cultivated area, directly supporting Sustainable Development Goal (SDG 2). However, climate change is projected to widen yield gaps of rainfed rice by 15–30% by the 2040s under Representative Concentration Pathway (RCP) 8.5. Beyond this crop-by-crop synthesis, the review proposes a constraint-transition framework in which the dominant type of limiting factor shifts predictably from biophysical (water, climate) in the largest-gap rainfed systems to agronomic management (nitrogen, sowing date, variety) at intermediate gap levels and to institutional and socioeconomic constraints (credit, extension, land tenure, gender) as gaps narrow in the best-resourced irrigated systems, thus offering a conceptual lens for prioritising interventions by development stage rather than by crop alone. Full article

Nature-Based Solutions (NBS) have emerged as a key strategy to address complex and intensifying urban sustainability challenges, yet empirical assessments of regulatory frameworks that operationalize these strategies remain limited. This study addresses that gap through an empirical evaluation of the Green Area Ratio (GAR), a hybrid performance-based zoning regulation for sustainable landscapes in Washington, DC, using more than a decade of regulatory implementation data. Regulatory plan approval records from 1329 private properties subject to GAR between 2015 and 2025 were analyzed to examine trends in landscaping Best Management Practice (BMP) selection, relationships with parcel characteristics, and interactions with stormwater management requirements. Over this period, approximately 184 ha of multifunctional NBS were approved through GAR plans primarily consisting of landscaping areas, plantings, and tree planting and preservation, often combined through BMP stacking and amplified by a native plant bonus. BMP selection varied significantly according to zoning district, lot area, and GAR Score Requirement. Importantly, GAR requirements influenced BMP selection differently than stormwater requirements. The findings suggest that simplicity, flexibility, and adaptability of the GAR make the regulation a versatile policy instrument for DC and a useful model for cities seeking to expand NBS through performance-based zoning regulation. Full article

The Duolong district in the central Bangong-Nujiang Suture Zone (BNSZ) is a major porphyry–epithermal Cu-Au cluster in Tibet. We combine radially averaged log-power spectra with a five-level db4 two-dimensional discrete wavelet transform (2D-DWT) to compare depth-sensitive frequency bands with their plan-view expressions in complete Bouguer gravity and reduced-to-the-pole (RTP) aeromagnetic grids. The five-level transform yields signed detail reconstructions d1–d5, ordered from fine to coarse scales, and a final cumulative low-pass approximation a5. The gravity/magnetic spectral estimates are 1.02/1.09 km for the shallow ensemble, 5.12/4.85 km for the intermediate ensemble, and 18.60/21.58 km for the deepest resolved ensemble. These values describe statistical source-depth ranges rather than discrete interfaces. The 2.98 km difference between the deep-source estimates (14.8% of the paired mean) is treated as methodological uncertainty and/or a difference in the depths of the density and magnetization transitions rather than as quantitative identity. The coarsest detail d5 and low-pass approximation a5 express a broad upper-to-middle-crustal background transition and do not image the Moho or a mantle source. Co-located mid-scale gravity and magnetic anomalies are consistent with a composite intrusive–basement source region, but the absence of site-specific density and susceptibility measurements prevents a unique lithological assignment. A southeastern anomaly zone centered approximately at 84.0° E, 31.7° N is therefore presented as a first-order regional screening hypothesis within a broad 3–8 km source-depth band, not as a quantitatively closed drill target. The interpretation distinguishes geophysical observations from geological hypotheses and explicitly incorporates the limitations of spectral and wavelet separation. Full article

As climate change intensifies and urbanization continues, Fuzhou faces growing public health risks from the urban heat island effect. This study develops a Heat Risk Index (HRI) by integrating the Local Climate Zone (LCZ) classification with the Crichton Risk Triangle framework. Hazard was characterized using quality-controlled Landsat LST and the proportion of valid MYD11A2 composites exceeding a citywide P90 LST threshold. Exposure was represented by normalized population density; ln(P + 1) was used only for cartographic classification. Vulnerability incorporated older population, nighttime light, NDVI, and MNDWI. The continuous HRI was calculated as H × E × V, and ln(HRI) was used only for Jenks five-class map presentation. The results show clear spatial differences among LCZ types and counties, with higher risks concentrated in densely built and populated areas of the five urban districts, Changle, and localized county centers. LCZ differences in LST and HRI were statistically significant (both p < 0.001), and HRI showed significant positive spatial autocorrelation. These findings provide a basis for LCZ-specific heat-risk management while acknowledging uncertainty associated with data-year mismatch, spatial resampling, remotely sensed surface temperature, and the absence of independent health-outcome validation. Full article

Improving the flood adaptability of urban waterfront spaces is an essential entry point for enhancing regional stormwater regulation capacity, scientifically preventing flood disasters, and stabilizing urban water security. Existing flood adaptability assessments mostly rely on single weighting methods and individual evaluation models, inevitably causing systematic bias and low result robustness. Against this limitation, this study integrates remote sensing intelligent interpretation, spatiotemporal landscape pattern analysis, and multi-criteria decision theory to construct a comprehensive flood adaptability evaluation system under the pressure–state–response (PSR) framework. Innovatively, a game-theoretic combined weighting scheme integrating the entropy weight method, CRITIC method, and standard deviation method is proposed, and three complementary models including TOPSIS, VIKOR, and EDAS are coupled for cross-verification evaluation, which effectively improves the objectivity and robustness of spatial flood adaptability quantification. Taking Anqing City as a typical case, this study adopts Sentinel-2 time-series remote sensing images from 2016 to 2023 and applies an optimized random forest algorithm to automatically classify land cover. Five underlying surface types, including water bodies, vegetation, farmland, built-up areas, and bare land, are accurately extracted with an overall classification accuracy of around 90% for most years. Core landscape metrics such as Shannon’s diversity index and patch density are selected to systematically analyze the spatiotemporal differentiation characteristics of waterfront landscape patterns during the study period. The results indicate the obvious spatial heterogeneity of flood adaptability in Anqing City. Yingjiang District and Yuexi County present high comprehensive flood adaptability, while Wangjiang County and Huaining County show relatively low performance. Urban areas gain strong flood resistance from complete disaster prevention infrastructures and economic resilience; mountainous areas possess natural advantages in flood retention and drainage due to high vegetation coverage and topographic relief; by contrast, plain districts are severely restricted by low-lying terrain and insufficient drainage systems, resulting in prominent flood vulnerability. The proposed method is helpful for providing reliable scientific support for waterfront landscape optimization, zoned flood disaster management, and resilient water space planning in riverine cities. Full article

The Jiaoxibei gold cluster is one of the most significant gold-producing regions in China and retains substantial regional prospecting potential. However, the superposition of multiple mineralization events has resulted in strong spatial coupling, multi-scale variability, and substantial redundancy among structural, alteration, geophysical, and geochemical information, limiting the effective extraction of key ore-controlling features. This study developed a geologically constrained feature-engineering framework for regional mineral potential evaluation. An initial indicator system comprising 32 geologically meaningful factors was constructed from structural geometry, remote-sensing alteration, gravity, magnetic, and geochemical information. The previously developed SOMML method was extended by introducing borehole-derived geological constraints to construct G-SOMML and generate the comprehensive geochemical anomaly factor Chem_F. Correlation-based redundancy reduction, Random Forest importance evaluation, SHAP interpretation, and geological screening were then combined to identify nine core factors. The selected factors were subsequently transformed according to their mineralization-response directions and integrated through category-balanced fuzzy synthetic evaluation. By linking geology-guided feature construction, borehole-constrained geochemical anomaly extraction, data-driven feature diagnosis, and balanced evidence integration, the framework provides a reproducible and interpretable workflow for organizing heterogeneous geoscientific information in regional mineral potential evaluation. The resulting high-potential zones captured 21 of the 22 known gold occurrences in the Sanshandao and Jiaojia areas and 17 of the 23 occurrences in the other parts of the study area, yielding an overall deposit capture rate of 84.4%. Compared with the all-feature fuzzy synthetic evaluation model (AT-Fuzzy), feature engineering reduced the high-potential area ratio from 50.951% to 25.356% while increasing the deposit capture rate from 51.1% to 84.4%. At the map level, the proposed framework delineated a substantially smaller high-potential area than the Random Forest model while achieving higher deposit capture rates than both the Random Forest and Weights of Evidence models under the common evaluation domain and statistical thresholding criterion. These results support the applicability of the framework for interpretable regional mineral potential evaluation and target prioritization in complex metallogenic districts. Full article

Surface deformation in rapidly urbanizing coastal cities is often shaped by the interplay between hydrogeological setting and development disturbance, yet these controls remain insufficiently constrained in tropical coastal environments. Using 119 ascending Sentinel-1A scenes acquired between September 2020 and August 2025, we derived a high-density line-of-sight (LOS) deformation field over Haikou, China, through the combined use of PS-InSAR and DS-InSAR time-series analysis. The results show pronounced spatial heterogeneity, with negative LOS anomalies concentrated in reclaimed coastal sectors, port-adjacent zones, and Jiangdong New District, where cumulative LOS displacement locally approaches 90 mm. DS-InSAR increased the number of valid observations to 764,573, approximately 2.8 times that of PS-InSAR, and showed good internal consistency with collocated PS estimates (R² = 0.8048). Positive LOS zones are present but are generally weaker and more spatially diffuse than the major negative anomalies, indicating that the near-zero city-wide mean partly reflects compensation between localized negative and positive signals. Spatial attribution analysis suggests that groundwater type, aquifer water-yield property, and geological zoning provide the main hydrogeological background associated with deformation, whereas human activity intensity, road density, and land-use intensity are associated with stronger negative deformation where hydrogeological conditions are susceptible. Because the dataset is limited to a single ascending viewing geometry, the reported deformation is interpreted as LOS motion rather than a fully resolved vertical subsidence field. These results support a cautiously framed interpretation in which coastal urban deformation in Haikou is hydrogeologically conditioned and development-amplified, providing a basis for targeted monitoring and risk-informed planning in newly developed coastal districts. Full article