Search Results (4,724)

Grain production resilience forms a critical foundation for national food security, and the ongoing development of land transfer provides essential momentum for establishing a more resilient grain production system. Using panel data from 30 provincial-level regions from 2013 to 2024, this study constructs a multi-dimensional evaluation system for grain production resilience and calculates the comprehensive grain production resilience index using the entropy value method. This study applies two-way fixed effects and mediation models to empirically analyze the impact of land transfer on grain production resilience and its underlying mechanisms. The results show the following: (1) Land transfer significantly enhances grain production resilience: a 1 percentage point increase in the land transfer rate leads to a 0.0014-point increase in the resilience index, equivalent to 0.64% of the sample mean, and this finding remains robust after model replacement, extreme value trimming, and variable substitution. (2) Land transfer exerts its positive effect through three mediating pathways: agricultural insurance (scale dimension), specialized farmer cooperation, and agricultural mechanization. (3) Heterogeneity analysis reveals significant regional differences: the enhancing effect is more pronounced in non-major grain-producing regions and areas with underdeveloped agricultural service systems; while in major grain-producing regions and high-service-level regions, the relationship presents an inverted U-shape, with turning points at 66.794% and 71.921% of the land transfer rate respectively. Accordingly, this study proposes that China should further improve the institutional design of land transfer to systematically support the development of grain production resilience, optimize relevant policy pathways, and implement region-specific measures for targeted and effective intervention. Full article

As a strategic node of the Silk Road Economic Belt and a prototypical valley-type city, Lanzhou is subject to the dual constraints of rapid urbanization and an inherently fragile ecological foundation, making the coordination between urban expansion and ecosystem services a critical issue for regional sustainability. Drawing upon multi-temporal land use remote sensing datasets provided by the Chinese Academy of Sciences Resource and Environment Science Data Center, in conjunction with soil, meteorological, and socio-economic data, this study integrates a land use transition matrix, the InVEST model, a modified coupling coordination degree model, and the geographic detector to comprehensively examine land use dynamics, the spatiotemporal evolution of urban expansion, and the spatial heterogeneity of ecosystem services (i.e., carbon storage, water yield, habitat quality, and soil conservation) in Lanzhou. In addition, the coupling coordination relationship and its underlying driving mechanisms are systematically explored. The results demonstrate the following: (1) Between 1980 and 2020, urban land area in Lanzhou increased from 103.87 km² to 286.83 km², accounting for 2.17% of the total area, with cropland constituting the dominant source of expansion and exhibiting a fluctuating “high–low–high” conversion trajectory. (2) Ecosystem services exhibit pronounced spatial heterogeneity, with carbon storage and habitat quality displaying a pattern of “low in the southeast and high in the northwest”, water yield showing an increasing gradient from southeast to northwest, and soil conservation characterized by “lower values in central areas and higher values in peripheral regions”; (3) Urban expansion has accelerated significantly, with Yongdeng County and Gaolan County emerging as principal expansion hotspots during 2010–2020. (4) The dominant driving mechanism gradually shifted from natural factors to the synergistic interaction between natural and socioeconomic factors, and the interaction among driving factors markedly enhanced the explanatory power for ecosystem service evolution. (5) The coupling coordination degree has transitioned from widespread imbalance to a spatially differentiated pattern, characterized by relatively coordinated conditions in peripheral areas and persistent imbalance within the central urban core. These findings provide a robust scientific basis for territorial spatial optimization and the synergistic development of ecological and economic systems in valley-type cities, and offer important implications for sustainable development in arid and semi-arid regions. Full article

To address the challenges of significant vehicle parking constraints, limited UAV endurance, and insufficient multi-task coordination efficiency in distribution network inspection, this paper proposes a vehicle–UAV synchronous cooperative inspection task scheduling method based on multi-objective twin delayed deep deterministic policy gradient and nondominated sorting genetic algorithm II (MOTD3-NSGA-II). First, a vehicle–UAV synchronous cooperative inspection model is established by considering staged vehicle repositioning, same-site UAV launch, landing, and retrieval, as well as state-of-charge constraints. On this basis, a multi-objective optimization model is formulated with task coverage, mission completion time, minimum residual state of charge, and load balance as objectives. Then, a bi-level closed-loop solution framework is developed, in which NSGA-II is employed to optimize cooperative parameters and objective preference weights, while the inner-layer MOTD3 learns UAV scheduling policies in a continuous action space. Finally, the proposed method is validated in four simulation scenarios with different task scales and spatial distribution characteristics. The results show that 100% task coverage is achieved in all four scenarios, with mission completion times of 11,109 s, 9693 s, 10,538 s, and 10,721 s, respectively, while the minimum residual state of charge is maintained within 0.28–0.36. The results demonstrate that the proposed method can balance inspection completeness, execution efficiency, energy safety, and cooperative stability, providing a useful reference for intelligent task scheduling in vehicle–UAV cooperative distribution network inspection. Full article

This study applies and evaluates established machine learning (ML) models for predicting monthly PM2.5 concentrations across the Greater Klang Valley (GKV), Malaysia using one year of data collected from 36 mobile monitoring stations between July 2022 and June 2023. Daily PM2.5 temperature (T), relative humidity (RH), and station location (L) were aggregated to form monthly datasets. Exploratory analysis showed substantial temporal variability, with elevated PM2.5 levels during the southwest monsoon and reduced concentrations during the northeast monsoon due to enhanced rainfall washout. Tree-based ML algorithms: decision tree (DT), random forest (RF), and Extreme Gradient Boosting (XGBoost) were developed following data cleaning, transformation, partitioning, and hyperparameter optimization via grid search. Model performance was evaluated using R², RMSE, MAE and NAE. Across all months, XGBoost consistently outperformed DT and RF, achieving the highest R² values (0.214–0.559) and generally lower error metrics. Model performance varied seasonally, with the highest accuracy observed in March 2023 (R² = 0.559) and February 2023 (R² = 0.552), whereas November 2022 showed the weakest predictive capability. Feature-importance analysis revealed that temperature exerted the strongest influence during the southwest monsoon, while station location dominated predictions in several months, reflecting spatial heterogeneity likely associated with land-use and emission patterns. RH was most influential in September 2022, when low humidity coincided with higher PM2.5 levels. Comparison of predicted and observed values showed strong alignment except during extreme pollution events, where the model tended to underperform. Overall, the findings demonstrate that XGBoost provides a robust modeling framework for monthly PM2.5 prediction in the GKV and highlights the importance of incorporating meteorological and spatial drivers to improve localized air-quality assessments. Full article

Satellite-observed greening in arid regions is often interpreted as ecological restoration success, yet this assessment may conflate natural recovery with agricultural expansion. We developed an Arid Remote Sensing Ecological Index (ARSEI) incorporating a Comprehensive Salinity Index (CSI) to address systematic biases in the traditional RSEI when applied to irrigated drylands. ARSEI scores were validated against MODIS Net Primary Production (NPP) ($R^2>0.75$ at the regional scale), confirming its reliability in capturing ecosystem productivity, while CSI effectively maps the upper-bound of surface salinization potential dictated by intrinsic soil properties. Applied to China’s Mu Us Sandy Land (2000–2024), the ARSEI reveals that 2327 km² of sandy land—54% of current cropland—was converted to agriculture, creating “assessment-induced false greening” signals. While the traditional RSEI increased monotonically (+135%), the ARSEI shows a nuanced pattern with plateau (2010–2015) and decline (2015–2020) phases, reflecting salinization risks masked by high crop NDVI. Optimal Parameters-Based Geographical Detector analysis demonstrates that Land Cover × Precipitation interactions (q = 0.28) drive spatial heterogeneity through irrigation-mediated water redistribution. The ARSEI provides a dialectical evaluation framework: acknowledging agricultural greening’s economic benefits while monitoring subsurface degradation risks. This study offers a critical methodological advance for sustainable land assessment in global drylands undergoing agricultural intensification. Full article

Efficient and reliable cooling is essential for ensuring the safety and performance of battery packs in electric vertical takeoff and landing (eVTOL) aircraft. To address the limitations of existing cooling methods in cooling capability and structural integration, this study proposes a hybrid cooling system combining air cooling, high-thermal-conductivity plates (HCPs), and phase-change material (PCM). The power demand in different eVTOL flight phases is first analyzed. A single-cell simulation model is then developed and validated through experiments. The effects of three key structural parameters on system performance are investigated, and their relative importance is quantified using sensitivity analysis. A multi-objective evaluation framework is further established to compare the proposed system with no cooling, passive cooling, and liquid cooling strategies. The adaptability of the hybrid cooling system under different operating conditions is also evaluated. Finally, an air-cooling intervention strategy is proposed based on the PCM liquid fraction. The results show that the optimized hybrid cooling system limits the maximum battery temperature and maximum temperature difference to 37.9 °C and 3.1 °C, respectively. Compared with passive cooling, the proposed system improves temperature stability by 44.6%. Compared with the liquid cooling system, space occupancy is reduced by 19.5%, and the grouping efficiency is increased by 22.4%. The adaptability analysis indicates that the optimized system is suitable for ambient temperatures not exceeding 30 °C. In addition, the proposed air-cooling intervention strategy reduces the air-cooling energy consumption by 43.3% compared with continuous air cooling, while maintaining temperature uniformity. These findings provide a numerical reference for the preliminary design of eVTOL battery cooling systems. Full article

As a policy-driven land use transition initiative bridging poverty eradication and sustainable development, China’s Poverty Alleviation Relocation (PAR) program exemplifies how state-led resettlement can reconfigure land use patterns while balancing immediate livelihood security with long-term community capacity development. The integration of large-scale PAR communities into new urbanization is a critical postrelocation task that is essential for consolidating poverty eradication achievements and enhancing endogenous development capacity. This study examined how the configuration of policy instruments shapes the endogenous development capacity of PAR communities during their transition to new urbanization. Employing a “tool–goal” analytical framework, we conducted a content analysis of 38 provincial-level policy documents (2021–present) using NVivo 20 software. The findings reveal that while local governments have established a preliminary policy system, structural imbalances persist: (1) uneven deployment of policy tools, (2) underutilization of demand-based policy tools, (3) tool–goal misalignment, and (4) insufficient market/societal participation in government-led measures. The discussion further reveals that the land use transition in the PAR program emphasizes the “living mode” (housing and public services) over the “livelihood mode” (productive resources and nonagricultural employment), creating structural dependency and leaving industrial land underutilized—as evidenced by weak policy support for industrial development (14.83%) and labour outmigration from resettlement areas. Drawing on the sustainable livelihoods framework, we further demonstrate how this exogenous-dominated policy mix disproportionately enhances physical and financial capital while constraining the accumulation of human and social capital—the very foundations of endogenous development capacity. To address these issues, we propose three key recommendations: (1) optimizing the policy mix to strengthen the endogenous development capacity of PAR communities; (2) realigning policy tools with objectives to achieve diversified yet coordinated goals; and (3) addressing implementation gaps to better leverage market mechanisms and social forces in promoting the sustainable urban integration of resettlement areas. Full article

Greece is facing a wildfire crisis that parallels many other countries in fire-prone regions around the globe. Recent wildfire data for Greece point to an alarming trend of increasing fire size and severity catalyzed by climate change, lack of forest and fuel management, urban expansion into wildlands around major population centers, and rural exodus from areas that traditionally supported fire-resilient land uses. Fire management in Greece has long emphasized suppression with relatively little attention to prevention and coordination. In this paper, we identify key factors that are slowing progress towards a solution to the Greek wildfire crisis, including the current legislative framework around wildfire management that has contributed to conflicts and inefficiency. We then discuss specific policies to rebalance the current suppression emphasis by integrating new prevention strategies aiming to create fire-resilient landscapes and reduce wildfire impacts, widely adopt the use of technology, and enhance stakeholder cooperation for more efficient fire suppression. We also highlight how optimizing landscape scale management of fuels is contributing solutions to the wildfire crisis, specifically from the EU-funded FIRE-RES project. Full article

Enhancing the willingness of rural–urban migrant workers (RUMs) to pursue the withdrawal of rural homesteads is a key measure to deepen the reform of the rural land system and advance new-type urbanization. This study aims to examine the impact of trade union participation on RUMs’ willingness to withdraw from rural homesteads (WFRH). It further offers implications for improving trade union services and refining relevant institutional arrangements for homestead withdrawal. Based on valid questionnaire data from 1949 RUMs in Hefei, Anhui Province, China, analytical methods, including the ordered Probit model, Propensity Score Matching (PSM), and KHB model, are adopted for empirical analysis. The main conclusions are as follows: trade union participation significantly enhances RUMs’ willingness to WFRH. This conclusion remains robust after the replacement of explained variables, adjustment of econometric models, and use of the PSM method to correct for selection bias. Heterogeneity analysis based on an ordered probit model reveals that the impact of trade union participation on homestead withdrawal willingness is more pronounced among females, individuals under 45 years old, and those with a college degree or above. Mediation effect test based on the KHB model finds that urban identity and sense of social fairness play mediating roles between trade union participation and RUMs’ homestead withdrawal willingness. Trade union participation improves their withdrawal willingness by strengthening their urban identity and sense of social equity. Efforts should be made to enhance the willingness of RUMs to withdraw from homesteads by improving the service function system of “capacity cultivation + rights protection + emotional connection” of trade unions, expanding the effective coverage of trade union organizations, promoting the collaborative linkage between “trade unions and governments”, and strengthening the full process service support for homestead withdrawal. The study conclusions help optimize the allocation of rural land resources and advance the integration of urban and rural development. Full article

Solar energy is emerging as a cornerstone of the global renewable energy transition, with projections indicating that photovoltaics (PV) could contribute up to 90% of electricity generation by 2050. However, environmental factors, particularly dust deposition, pose a significant challenge to the long-term performance and efficiency of PV systems. Dust accumulation varies widely across different geographic regions, influenced by climate, land use, humidity, and pollution. Arid and semi-arid areas experience the highest deposition rates, while tropical and temperate regions are affected by seasonal rainfall and urban pollutants. This review comprehensively examines the impact of dust on PV performance, highlighting factors such as surface roughness of PV module, panel tilt angle, seasonal variations, wind dynamics, and dust composition. Furthermore, the review assesses various dust mitigation strategies, including manual and water-based cleaning, robotic systems, hydrophobic coatings, and electrostatic methods. By synthesizing global studies and presenting a holistic view of dust effects, this paper provides critical insights into the impact of performance degradation with regional variation in PV, optimizing performance, maintenance, and effective dust mitigation strategies to ensure sustained energy yield and reliability in solar energy systems worldwide. Full article

Against the backdrop of urbanization and global warming, reducing carbon emissions and achieving carbon neutrality have emerged as focal points in current urban ecological research. Urban green infrastructure (UGI) serves as the primary natural carbon sink within cities; therefore, investigating and optimizing its carbon sequestration services is a crucial step toward realizing carbon neutrality and fostering sustainable urban development. As the core components of urban ecosystems, urban parks provide essential ecosystem services that play a pivotal role in expanding carbon sinks, facilitating energy conservation and emission reduction, and enhancing urban climate resilience. This paper takes 20 parks in Linyi City’s central urban area as examples, systematically quantifies the carbon sequestration effect of urban parks in the central urban area of Linyi City from 2019 to 2024 using methods such as the Carnegie–Ames–Stanford Approach (CASA) and the gravity model, and quantitatively evaluates the equity of urban residents’ access to these services. The study shows that the overall annual average carbon sequestration rate of urban parks in Linyi City’s central area over nearly six years ranges from 202.02 gC·m⁻²·a⁻¹ to 279.31 gC·m⁻²·a⁻¹, while individual park annual averages range from 171.29 to 332.76 gC·m⁻²·a⁻¹, falling within the normal range for cities at the same latitude; in terms of vegetation carbon sequestration capacity, woody plant communities dominate in this region, with annual average carbon sequestration rates approximately 10% higher than those dominated by herbaceous vegetation. In terms of intrinsic activity performance of carbon sequestration, overall, woody-dominated plant communities exhibit greater stability and resilience under extreme weather conditions, experiencing smaller impacts on ecological functions but longer recovery cycles to peak levels. Regarding equity in the supply and demand of ecosystem services, the Gini coefficient in the study area is 0.59, indicating an extremely imbalanced state; within the same park service range, up to 60% of residents do not benefit from carbon sequestration ecosystem services. The urban supply–demand mismatch reveals that approximately 20% of the population resides in high-demand–low-supply areas, experiencing extreme ecological deprivation; only about 13% of the population falls into the high-demand–high-supply category, this group being the high-benefit recipients who enjoy both spatial convenience and high-quality ecological welfare. The theoretical implications for urban green space planning: according to the results, merely expanding park green space area to increase per capita access is myopic and inadvisable in central urban park planning. Instead, greater emphasis should be placed on enhancing ecological service levels beyond basic area requirements, comprehensively improving vegetation quality and ecosystem service capacity of parks. In old urban areas constrained by land use, the hierarchical structure of vegetation should be strengthened, and micro green spaces should have enhanced ecological service capabilities to improve residents’ access rights through higher service quality. In newly developed urban areas, planning should balance quantity and quality to serve more people and alleviate urban ecological pressures. Overall, by quantitatively assessing the carbon sequestration capacity and the socio-spatial equity of ecosystem services provided by urban parks in Linyi City, this study offers robust empirical evidence and methodological tools for sustainable urban planning, ultimately fostering the sustainable development of urban ecosystems. Full article

This study examines the associations of land temperature anomalies and energy-related CO₂ emissions per hectare with wheat and maize yields in Romania and Serbia during 1992–2023. Energy-related CO₂ emissions per hectare are used as a scale-adjusted proxy for energy-use intensity and emissions associated with agricultural energy consumption, rather than as an indicator of climate intensity. The study contributes to the literature by applying a comparative ARDL framework to Romania and Serbia, two Central and Southeast European agricultural systems with different institutional contexts, integrating climate variability, nitrogen fertilizer use and energy-use-related emissions into a unified crop-specific analysis. Using the Autoregressive Distributed Lag (ARDL) framework, we estimate long-run equilibrium relationships and short-run dynamics between cereal yields and the selected explanatory variables. The results partially support the proposed hypotheses by indicating heterogeneous country- and crop-specific relationships. In Romania, nitrogen fertilizer use is positively associated with wheat and maize yields, while rising land temperature anomalies are negatively associated with maize productivity. In Serbia, energy-related CO₂ emissions per hectare show a statistically significant negative long-run relationship with maize yields, whereas no statistically robust long-run relationships are identified for wheat. The findings highlight the importance of energy efficiency, input optimization and country-specific decarbonization strategies for sustainable cereal production. Full article

Reclaiming saline–alkaline soil is critical for food security and land expansion. While paddy rice is the key pioneer crop for remediation, the soil fertility–yield relationship remains poorly understood. To optimize remediation strategies, this study evaluated soil fertility under 16 agronomic treatments—integrating irrigation quality, fertilizer regimes, and soil amendments—across three rice growth stages (tillering, heading, and maturity) in the Yellow River Delta using the minimum data set (MDS), integrated soil fertility index (SFI), and random forest models. Saline water irrigation increased soil salinity by 24.6%, while straw returning and desulfurization gypsum reduced salinity by 18.3% and 22.7%, respectively. Straw, biochar, and desulfurization gypsum significantly influenced soil organic carbon (SOC), total nitrogen (TN), inorganic nitrogen (NH₄⁺-N, NO₃⁻-N), and available phosphorus (AP), with effects varying across growth stages. Growth-stage-specific MDS indicators were significantly correlated with SFI based on the total data set (R² = 0.70, 0.65, and 0.81, p < 0.01), and stage-specific SFI was significantly positively related to rice yield. Notably, heading-stage SFI, although relatively low, explained the highest yield variance (R² = 0.51, p < 0.01) and prediction accuracy (%IncMSE = 25.22), especially under conventional NPK combined with full straw incorporation and desulfurization gypsum. These findings highlight the critical role of heading-stage soil fertility in regulating rice production, providing a targeted nutrient management blueprint for saline–alkaline paddy fields in the Yellow River Delta. Overall, this study offers a reliable scientific template to enhance yield and promote sustainable agriculture in comparable saline–alkaline paddy fields globally. Full article

The rural collective property rights system reform (RCPRSR) is a pivotal institutional innovation for revitalizing rural resources, optimizing factor allocation, and advancing urban–rural integration—a core goal of sustainable land use planning. This study evaluates the reform’s impact on county-level urban–rural integration using panel data from 1106 Chinese county-level administrative units during 2013–2020. Treating the staggered rollout of reform pilots as a quasi-natural experiment, we employ a multi-period difference-in-differences approach. The results show that the RCPRSR significantly promotes urban–rural integration, a finding robust to a series of sensitivity checks. The policy effects exhibit marked heterogeneity: the dividends of narrowing the urban–rural development gap are more pronounced in poverty-stricken counties and areas with lower baseline integration levels. Mechanism analysis reveals two pathways—population agglomeration and industrial structure optimization—through which the reform operates, specifically manifested as enhanced county population carrying capacity, accelerated tertiary industry development, and deepened secondary–tertiary industrial integration. These findings provide empirical evidence for optimizing rural property rights reform and advancing sustainable urban–rural development. Full article

Drought exhibits a complex coupling response to regional meteorological factors, hydrological characteristics, land cover, and large-scale teleconnection climate indices, while their direct and indirect influences on multi-scale meteorological and hydrological droughts remain insufficiently understood, particularly in karst basins. This study investigated drought dynamics in China’s Yujiang River Basin using an integrated framework combining run theory, drought propagation analysis, and the partial least squares–structural equation model (PLS-SEM). We analyzed the 1-, 3-, 6-, and 12-month standardized precipitation index (SPI) and standardized streamflow index (SSI) at four hydrological stations during 1984–2014, together with meteorological factors, land cover indices, large-scale climate indices, areal precipitation, and naturalized streamflow. The results show that precipitation and streamflow exhibited slight declining tendencies with marked seasonal variability, and that drought durations of all severity levels generally decreased with increasing time scales. At the same time scale, SSI was more stable than SPI, and both indices tended to become more stable as the time scale increased. SPI-3 and SSI-1 were identified as the optimal time scales for monitoring meteorological and hydrological drought, respectively, providing a practical basis for drought identification and early warning in karst basins. Hydrological drought lagged meteorological drought by 1–3 months, indicating a measurable propagation time that is valuable for improving drought preparedness and water resources regulation. PLS-SEM further revealed that precipitation and streamflow were the dominant direct drivers of drought development, while land cover exerted a persistent negative effect, and climate-related factors mainly influenced drought indirectly. These findings enhance the understanding of drought propagation and multi-factor coupling mechanisms in karst basins and provide scientific support for regional drought monitoring and water resources management. Full article