Sustainable Resource Management Research Articles

Intermittent freshwater extraction and cold-water recharge for mitigating seawater intrusion in coastal aquifers

Decreasing groundwater temperature by freshwater extraction and cold-water recharge can mitigate seawater intrusion in coastal aquifers. However, the impact of frequently employed and easily executed intermittent well operations on this has been overlooked. This study numerically examines temperature and salinity distributions in coastal aquifers subject to intermittent freshwater extraction and cold-water recharge (IER) at an equal rate. Results show that IER maintains an equivalent effect on inhibiting seawater intrusion as the continuous method, while IER during cold seasons reduces operational time and cooling heat consumption. For instance, numerical test on a realistic aquifer shows that 90 d of IER could lead to a 75% decrease in operational time and a 29% reduction in cooling energy usage compared to the continuous method. The mitigation effectiveness depends on the averaged seaward hydraulic gradient, which is affected by heat storage reduction above the saltwater wedge. The cold-water plume from IER is convergently transported and discharged, creating a pronounced fluctuation of heat storage reduction and thereby resulting in a delayed periodic variation of the hydraulic gradient. As salt efflux is an integrated result of periodically changing hydraulic gradients, total salt mass exhibits a delayed and prolonged response to the variation of heat storage reduction. Sensitivity analyses show that a far recharge distance and reduced aquifer permeability increase the delay between heat storage reduction and total salt mass, and low recharge temperature facilitates seawater intrusion mitigation. This study demonstrates the importance of the intermittent method in inhibiting seawater intrusion and has implications for sustainable management of coastal groundwater resources.

Employee well-being as a mediating variable in sustainable human resource management, organizational commitment, and job satisfaction of healthcare professionals: A structural equation modeling approach

ABSTRACT Sustainable human resource management is a concept gaining attention worldwide from researchers and practitioners. This article is focused on nursing and exploring the influence of Sustainable Human Resource Management (SHRM) on Employee Well-Being (EWB) and the impact of EWB on Organizational Commitment (OC) and Job Satisfaction (JS) of healthcare employees. The study highlighted the need for hospital organizations to develop sustainable human resource management to enhance the well-being of healthcare professionals. A well-structured questionnaire (adapted, validated, and pre-tested) was prepared. Partial Least Square Structural Equation Modeling (PLS-SEM) using Smart PLS 4.0 was employed for testing the hypothetical relationships. Using the proportionate sampling technique, data were collected from 452 healthcare professionals employed in 55 private and 56 public sector hospitals in Punjab, India. The findings of the study revealed that there exists a significant relationship between SHRM and Employee WB, and employee well-being directly influences OC and JS. Moreover, study findings also revealed that employee well-being partially mediates the relationship between SHRM as an independent variable; and OC and JS as dependent variables.

Sustainable development and environmental protection in the Absheron peninsula: a geo-ecological perspective

The research focuses on the ecological and geographical aspects of the Absheron region in Azerbaijan, highlighting the significant environmental challenges and the need for sustainable resource management. Given the region’s rapid economic development and urbanization, there is a crucial need to balance economic growth with environmental conservation to ensure long-term ecological stability. The Absheron region faces numerous environmental issues due to intensive industrial activities, particularly in the oil and gas sectors, and increasing urbanization. These activities have led to significant anthropogenic impacts, necessitating comprehensive studies to assess and mitigate their effects on the natural environment. The article’s primary aim is to analyze the current dynamics of economic progress in the Absheron peninsula, assess the anthropogenic impacts, and identify efficient strategies for environmental management. The study also aims to provide a comprehensive ecological survey of the region, focusing on sustainable green economic practices. There has been significant urban growth in cities like Baku, Sumgayit, and Khyrdalan, contributing to increased environmental pressure. Modern settlements and infrastructure development have played a crucial role in organizing advanced systems for economic purposes. The economic activities, particularly in the oil sector, have significantly impacted the region’s natural complexes, necessitating the implementation of green economy principles. Effective management practices are essential to prevent pollution, maintain ecological balance, and protect natural resources. The study highlights the importance of greening initiatives and emergency response plans to manage environmental risks. The author emphasizes the need for a balanced approach to economic development and environmental conservation in the Absheron region. The study provides valuable insights into the ecological and geographical challenges of the Absheron region and offers practical solutions for achieving sustainable development. The article outlines the potential of geographic information systems and remote sensing technologies in monitoring and managing environmental change, in particular, in assessing the impact of industrial activity and urban expansion. The results of the study indicate the need for a comprehensive policy that combines economic development goals with environmental protection measures to ensure long-term environmental sustainability and economic prosperity in the Absheron Peninsula.

Relationship of professional identity and efficacy of Chinese public university lecturers under the appointment system in sustainable human resource management

For Chinese university lecturers, implementing sustainable human resource management (SHRM) is particularly critical. China's higher education is going through an essential stage of appointment system reform aiming to overturn the traditional civil service status of university lecturers and introduce a more flexible work and talent management mechanism to universities to international teaching standards; lecturers also raise concerns about their professional role, educational mission, balance of rights and interests, and the reshaping of the evaluation system. Based on the resource-based perspective and psychological contract theory, this study aimed to explore the relationship between sustainable human resource management (SHRM) and lecturers' professional identity in the context of China's appointment system, focusing on analyzing the moderating role of lecturers' self-efficacy. This study used a quantitative research approach to collect survey data from 610 lecturers at public colleges and universities in China. The data were analyzed with a structural equation model to test the hypothesized relationships. SHRM was directly and positively related to lecturers' self-efficacy and sense of professional identity and indirectly improved sense of professional identity by enhancing self-efficacy. The findings are consistent with existing literature, emphasize the importance of SHRM in promoting lecturers' career development, and provide empirical support for applying SHRM in the context of Chinese higher education. The study provides recommendations in three dimensions: Government, University, and Faculty. It provides guidance for strategic reform of human resource management in higher education, faculty career development, and improving education quality.

Research on Employee Green Behavior from the Perspective of Sustainable Human Resource Management: The Role of Diversity, Inclusion, and Well-being

Enterprises are increasingly prioritizing social and ecological issues, cultivating sustainable Human Resource Management (HRM), and focusing on the sustainability of both people and the environment to achieve overall Sustainable Development Goals (SDGs). This study primarily draws on green HRM, selecting four key variables, including organizational diversity and inclusion, employee well-being (EWB), work stress, and employee green behavior (EGB), focusing on Chinese enterprises. This study employs quantitative research and Structural Equation Modelling (SEM) analysis to explore the relationships among these variables, aiming to promote internal green behavior within organizations and achieve SDGs. Data were collected from a randomly selected sample, resulting in a valid sample size of 453 questionnaire responses after data cleaning. The research found that organizational diversity and inclusion have a positive impact on EWB and EGB. There is also a positive correlation between EWB and EGB. However, organizational diversity and inclusion are negatively related to work stress, and work stress is negatively related to EGB. EWB and work stress mediate the relationship between organizational diversity, inclusion, and EGB. This study deepens the understanding of the relationship between diversity, inclusion, well-being, and green behavior, providing new directions for future research, and offering pathways for organizations to improve their environment and EWB to promote social sustainability.

Do ICT and green technology matter in sustainable development goals?

AbstractThe desire for development in developed and developing countries has caused difficulties in realizing environmental goals. For this reason, initiatives such as Sustainable Development Goals have been taken to balance economic growth and environmental goals. Recent research from a sustainable development perspective has shown that skilled human capital, green technology, and ICT play an essential role in the sustainable management of natural resources. In this context, the present study aims to reveal the impact of natural resource rent, economic complexity, human development, green technological innovation, and ICT on ecological footprint. It also focuses on the moderating role of green technological innovation and ICT in the relationship between natural resource rent and ecological footprint. The findings show that natural resources and ICT are the causes of environmental degradation in G7 countries, whereas economic complexity, human development, and green technological innovation improve environmental quality. It has also been discovered that ICT and green technological innovation have a moderating role in the natural resources of G7 countries. In E7 countries, natural resource rent and economic complexity increase environmental degradation, whereas human development, ICT, and green technological innovation contribute to environmental quality. Causality findings are similar in both country groups. The findings show that synergies between SDG‐4 and SDG‐13 in G7 and E7 countries can help achieve climate action sustainably and effectively. Moreover, achieving SDG 13 in E7 countries requires interactive policies to achieve SDG‐12 and SDG‐17. Achieving SDG‐8 and SDG‐17 targets in G7 countries can contribute to combating climate change.

Participatory Environmental Governance and Payments for Environmental Services: the Strategic Role of Universities

Objective: The objective of this study is to investigate the integration of Participatory Environmental Governance into Payment for Environmental Services (PES) programs, with the aim of proposing a theoretical model that actively involves universities as facilitators in this process. Theoretical Framework: The theories of Participatory Environmental Governance and the Payment for Environmental Services model are highlighted, providing a solid foundation for understanding the research context. Method: A theoretical and qualitative approach is used. The study involves a review of existing literature on PES and Participatory Governance, followed by a discussion of the limitations of current models and the proposal of a new framework for the proposed integration. Results and Discussion: The results revealed the potential effectiveness of Participatory Environmental Governance in improving the equity and sustainability of PES programs. The relationships between community participation, universities, and the success of PES are highlighted. Research Implications: The implications of this research can be applied to public policies and environmental management practices. These implications may encompass areas such as environmental education, conservation policies, and the role of universities in sustainability. Originality/Value: This study contributes to the literature by proposing a novel integration between Participatory Environmental Governance and PES programs, highlighting the strategic role of universities. The relevance and value of this research are evidenced by its potential application in different contexts, promoting more participatory and sustainable natural resource management.

Geological factors in the sustainable management of mine water heating, cooling and thermal storage resources in the UK

Re-use of the UK's coal mine water heating, cooling and thermal storage resource is increasing in scale and the number of schemes. The upward trajectory requires 3D planning, regulation and licensing to manage sustainable deployment. We review geological factors controlling thermal and flow processes in the anthropogenically-altered subsurface, critical for resource management with multiple users of the same space. Potential interactions of mine water geothermal schemes with the wider environment are also summarized, leading towards concepts of 3D mine water thermal blocks, protection zones, or management strategies integrating heating, cooling and storage demands. Factors such as the magnitude, extent and timescale of thermal processes to underpin management approaches are poorly quantified by data measured at-scale under varying pumping rates and thermal loads. We demonstrate early insights of how two infrastructures, the UK Geoenergy Observatory in Glasgow and the Coal Authority's Mine Water Heat Living Lab in Gateshead, can measure and monitor heat-flow processes in real world settings to provide an evidence base. For example, a thermal storage test at Glasgow showed rapid temperature changes in the rock and mine workings at the re-injection borehole and indicated an influence of lithologically-controlled transmissivity and thermal conductivity on temperature dissipation and recovery.

Large pelagic fish exploitation by longliners in the Atlantic Ocean and Mediterranean Sea: A contribution to spatial planning and sustainable fisheries

Understanding longline fisheries dynamics is crucial for sustainable resource management. This study aims to provide a panorama of the fishing effort of the principal nations that have exploited tuna and associated species in the Atlantic Ocean for the past decade, integrating vessel data from Global Fishing Watch (GFW) and catch data from the International Commission for the Conservation of Atlantic Tunas (ICAAT), with specific information on the production of these different fleets and resources. Twelve nations represented 94.6 % of all Apparent fishing hours (AFH) of the total effort in the Atlantic Ocean and 99.9 % of all catches in the last years. Our study revealed that regions proximate to the continental shelf break and oceanic islands exhibit notably higher fishing effort than other areas within the Atlantic Ocean. We also highlight a declining trend in fishing efforts in the last ten years, likely due to regulation and overfishing. The blue shark (Prionace glauca) was the most caught species in biomass, representing 38.1 %; bigeye tuna (Thunnus obesus) represented 20.5 %; swordfish (Xiphias gladius) 15.1 %; albacore tuna (Thunnus alalunga) 11.3 %, and yellowfin tuna (Thunnus albacares) 6.1 %. The alarming trends in pelagic shark catch emphasise the need for immediate conservation actions. Management strategies should target critical nations, addressing their significant contributions to shark catch. The lack of information on several species and periods highlights the need for comprehensive research and management initiatives.

Decision-making in closed-loop supply chains: Effects of government subsidies and risk aversion

Closed-loop supply chains (CLSCs) play a crucial role in promoting sustainable resource management, yet their implementation faces challenges in balancing economic viability with environmental goals. While existing research has explored various aspects of CLSC operations, the interplay between government subsidies and risk-averse behavior of supply chain members remains understudied, particularly in systems involving third-party recyclers. This gap hinders the development of effective policies and management strategies for sustainable CLSCs. Herein, we employ a Stackelberg game-theoretic model to investigate decision-making processes in CLSCs under four distinct subsidy scenarios, incorporating risk aversion through mean-variance utility functions. Our results reveal that subsidy effectiveness significantly depends on remanufacturing costs and risk attitudes of supply chain participants. When remanufacturing costs are high, subsidizing third-party recyclers yields superior environmental and economic outcomes, whereas manufacturer subsidies prove more effective when these costs are low. Moreover, we identify critical thresholds in subsidy levels and risk aversion that alter decision-making patterns. These findings provide a framework for designing targeted subsidy policies and risk management strategies in CLSCs, advancing the field of sustainable supply chain management by offering nuanced insights into the complex dynamics between government interventions, risk preferences, and CLSC performance.

Epoxy composite dust reinforced novel polypropylene composites: An eco‐friendly approach toward sustainable resource management

AbstractThis study presents an innovative technique for recycling leftover epoxy composites reinforced with natural fillers. The waste epoxy composites were successfully ground into a 75–150 μm fine powder. With the aid of extrusion injection molding, this powder was subsequently utilized to create polypropylene matrix‐based polymer composites with variable filler loadings ranging from 10% to 30%. The mechanical, thermal, thermomechanical, and morphological properties of the developed composites were assessed. The greatest tensile strength of the polypropylene composites produced with 10% filler loading was found to be 24.15 MPa. The addition of epoxy composite filler increased the thermal stability. During morphological investigations, it was discovered that pits, voids, and filler agglomerations predominated the fractured surface of the developed composites. Overall, it can be concluded that there is a lot of promise for value‐added recycling of thermosetting resin‐based composites using this low‐cost, high‐efficiency, and ecologically benign process, which would lessen the environmental impact of plastic.Highlights Novel polypropylene composites using epoxy composite dust was developed. Mechanical, thermal, thermomechanical, and morphological studies were performed. Toys, tableware, mementos, and furniture can be the potential applications. The developed composites can reduce plastic load on the environment.

A Quantitative Particle-Based Approach for the Geometallurgical Assessment of Tailings Deposits

Tailings generated during ore processing may host significant residual contents of valuable commodities, including critical metals. The particle properties of the tailings, such as mineralogy, particle size, and the surface liberation of ore minerals, strongly control processing behaviour. This study explores a novel combination of methods for incorporating particle data, derived from automated mineralogy, into geometallurgical models of tailings deposits to better understand their reprocessing potential and the economic feasibility of re-mining. This was achieved through binning of different particle types, geostatistical modelling of particle bin frequencies, and bootstrap resampling to reconstruct particle populations. The spatial distributions of processing-relevant particle properties throughout the tailings deposit were predicted with corresponding uncertainties. There are clear systematic trends in the spatial distributions of different particle types, resulting from the sedimentary-style deposition of the tailings. For instance, the tailings nearer the dam walls comprise coarser, silicate-rich particles, while fine-grained and well-liberated sulphide mineral particles are more abundant in the centre of the tailings deposit. As a result, robust models could be developed for the spatial distributions of particle size and mineralogy, which strongly control the sorting of particles during deposition, and other related properties, such as sulphide mineral grain sizes. Finally, a bulk sulphide flotation process was simulated and acid mine drainage potential estimated using the interpolated particle data. Around 58% of the sulphide minerals present could be recoverable by flotation, with the recoverable sulphide portion decreasing towards the centre of the TSF due to the fine-grained nature of the sulphide minerals. The acid mine drainage potential of the tailings is estimated to be moderate to high, indicating that the carbonate minerals present are not sufficient to neutralise the high acid-generating potential of the sulphide minerals. Overall, this study demonstrates how particle-based geometallurgical models can be developed and utilised for practical applications, with the aim of improving the accuracy of resource and reserve estimations of tailings deposits and the sustainable and responsible management of anthropogenic resources. The methodology proposed here can be easily transferred to other tailings deposits.

Unraveling Complexity: Exploring Agricultural Systems as Complex Adaptive System with a Focus on the Konya Closed Basin

The study of complex adaptive systems (CAS) has garnered significant attention across interdisciplinary research, particularly within the realms of social and natural sciences. This paper delves into the multifaceted nature of CAS, exploring its definitions, components, and properties, drawing from various scholarly perspectives. It examines the agricultural sector as a prime example of a CAS, highlighting the interactions, adaptations, and emergent behaviors within farming communities. Using the Konya Closed Basin in Türkiye as a case study, the paper elucidates how agricultural landscapes exemplify the complexities inherent in CAS, underscoring the intricate interplay between human activities, environmental dynamics, and socio-economic factors. By recognizing these interactions, decision-makers can create more efficient and resilient strategies for managing water resources, enhancing crop production, and reducing the effects of climate variability. This comprehensive approach emphasizes the role of adaptation, self-organization, and emergent behaviors in promoting sustainable farming practices and maintaining ecological balance over the long term. Through this analysis, the paper contributes to a deeper understanding of CAS and its implications for sustainable agricultural development and resource management.

LOCAL ECOLOGICAL KNOWLEDGE ON LAND SNAIL DIVERSITY IN MOUNT BANAHAW, PHILIPPINES

Local ecological knowledge (LEK) is a community-based conservation effort that promotes sustainable management of natural resources. However, studies on LEK are very limited in the Philippines. To address this information gap, LEK on land snails in Mount Banahaw, Luzon Island, Philippines was investigated. Key informant interviews and focus group discussions were conducted in the four communities (Dolores, Lucban, Tayabas and Majayjay) along the slope of the mountain. A snail calendar was used as a tool for identifying the hunting season and practices of these communities on land snails. The results showed that the communities were knowledgeable on macro land snails (>5 mm shell size) such as the introduced species, Lissachatina fulica and the endemic and edible, Ryssota otaheitana, but were unaware of micro land snails ( 5 mm shell size). Locals also demonstrated an awareness of the snails’ ecosystem functions as a food source for other animals and agents of nutrient cycling. Additionally, sustainable hunting of R. otaheitana in communities was observed. Only adult R. otaheitana were harvested, leaving the juveniles to grow and reproduce. In Lucban, the people hunted while they were waiting for the harvest season of their crops. In Tayabas, the community observed that the snail was abundant during wet and moist soil conditions when leaf litter, its primary food, decomposed easily. In Majayjay, hunting was associated with the blooming of the flowering plant, Erythrina variegata. In Dolores, hunting was practiced after clearing farmland. This research underscores the importance of determining LEK in developing policies and regulations on sustainable utilization and conservation of land snails in a tropical forest setting.

Hydraulic and Hydrogeochemical Characterization of Carbonate Aquifers in Arid Regions: A Case from the Western Desert, Egypt

Using geochemical and pumping test data from 80 groundwater wells, the chemical, hydrologic, and hydraulic properties of the fractured Eocene carbonate aquifer located west of the Al-Minya district, the Western Desert, Egypt, have been characterized and determined to guarantee sustainable management of groundwater resources under large-scale desert reclamation projects. The hydrochemical data show that groundwater from the fractured Eocene carbonate aquifer has a high concentration of Na+ and Cl− and varies in salinity from 2176 to 2912 mg/L (brackish water). Water–rock interaction and ion exchange processes are the most dominant processes controlling groundwater composition. The carbonate aquifer exists under confined to semi-confined conditions, and the depth to groundwater increases eastward. From the potentiometric head data, deep-seated faults are the suggested pathways for gas-rich water ascending from the deep Nubian aquifer system into the overlying shallow carbonate aquifer. This mechanism enhances the dissolution and karstification of carbonate rocks, especially in the vicinity of faulted sites, and is supported by the significant loss of mud circulation during well drilling operations. The average estimated hydraulic parameters, based on the analysis of step-drawdown, long-duration pumping and recovery tests, indicate that the Eocene carbonate aquifer has a wide range of transmissivity (T) that is between 336.39 and 389,309.28 m2/d (average: 18,405.21 m2/d), hydraulic conductivity (K) between 1.31 and 1420.84 m/d (average: 70.29 m/d), and specific capacity (Sc) between 44.4 and 17,376.24 m2/d (average: 45.24 m2/d). On the other hand, the performance characteristics of drilled wells show that well efficiency ranges between 0.47 and 97.08%, and well losses range between 2.92 and 99.53%. In addition to variations in carbonate aquifer thickness and clay/shale content, the existence of strong karstification features, i.e., fissures, fractures or caverns, and solution cavities, in the Eocene carbonate aquifer are responsible for variability in the K and T values. The observed high well losses might be related to turbulent flow within and adjacent to the wells drilled in conductive fracture zones. The current approach can be further used to enhance local aquifer models and improve strategies for identifying the most productive zones in similar aquifer systems.

Where has hydrogeologic science been, and where is it going? Research trends in hydrogeology publishing over the past 60 years

AbstractQuantifying historical research trends in the field of hydrogeology is not only generally informative for hydrogeologists but is essential for fostering interdisciplinary collaboration and assessing the relationship between academic study and societal interests in hydrogeologic issues. To address this, a topic model was applied to over 37,000 academic abstracts published in over 20 journals between 1963–2022 in the field of hydrogeology to study the evolution of topic trends through time. Model results were fed into the popular large-language model ChatGPT to assign topic names, representing an unsupervised method. The results indicate that, historically, popular topics related to methodological development and analytical and numerical models analytical and numerical methods in groundwater flow modeling and well hydraulics have given way to topics related to more increasingly complex models (groundwater monitoring and uncertainty estimation and groundwater modeling calibration and simulation) as data and computational capability becomes increasingly available. An insight into the period of boom-and-bust in contaminant hydrogeology is reflected by a shift in focus from topics related to assessment and characterization of contaminant sources toward topics related to degradation and remediation methods. Topics of emerging prevalence (sustainable groundwater resource management, catchment hydrology and runoff processes) in the current period reflect an increasing focus on treating the surface-water/groundwater system as a single system. In addition, results suggest that topic distribution within the field of hydrogeology has become more varied as time has progressed.

Systems Modeling of the Water-Energy-Food-Ecosystems Nexus: Insights from a Region Facing Structural Water Scarcity in Southern Spain.

The complex relationship between water, energy, food, and ecological systems, known as the WEFE nexus, has emerged as a major topic in the debate about sustainable economic development and resource management. This subject is of special interest in Mediterranean coastal areas as rapid economic expansion driven by population growth, higher influx of tourists, and intensification of agriculture is leading to structural water scarcity conditions. However, addressing the diverse range of issues associated with the nexus is a difficult task due to the existence of intricate interconnections, interdependencies, and nonlinearities within and across its various components. Accordingly, this case study applies a combination of participatory systems modeling and network analysis tools to yield insights into the complexity of this nexus in Axarquia, a region with features that make it an example of water-stressed jurisdictions in the Mediterranean. Overall, our results provide a strong foundation to understand the dynamics that govern this nexus in regions where the availability of freshwater resources is a significant concern. Furthermore, they lay the groundwork for the development of models and scenarios to simulate the impact of various policies and interventions on the overall system.

A Fully Connected Neural Network (FCNN) Model to Simulate Karst Spring Flowrates in the Umbria Region (Central Italy)

In the last decades, climate change has led to increasingly frequent drought events within the Mediterranean area, creating an urgent need of a more sustainable management of groundwater resources exploited for drinking and agricultural purposes. One of the most challenging issues is to provide reliable simulations and forecasts of karst spring discharges, whose reduced information, as well as the hydrological processes involving their feeding aquifers, is often a big issue for water service managers and researchers. In order to plan a sustainable water resource exploitation that could face future shortages, the groundwater availability should be assessed by continuously monitoring spring discharge during the hydrological year, using collected data to better understand the past behaviour and, possibly, forecast the future one in case of severe droughts. The aim of this paper is to understand the factors that govern different spring discharge patterns according to rainfall inputs and to present a model, based on artificial neural network (ANN) data training and cross-correlation analyses, to evaluate the discharge of some karst spring in the Umbria region (Central Italy). The model used is a fully connected neural network (FCNN) and has been used both for filling gaps in the spring discharge time series and for simulating the response of six springs to rainfall seasonal patterns from a 20-year continuous daily record, collected and provided by the Regional Environmental Protection Agency (ARPA) of the Umbria region.

High-resolution mapping of grassland canopy cover in China through the integration of extensive drone imagery and satellite data

Canopy cover is a crucial indicator for assessing grassland health and ecosystem services. However, achieving accurate high-resolution estimates of grassland canopy cover at a large spatial scale remains challenging due to the limited spatial coverage of field measurements and the scale mismatch between field measurements and satellite imagery. In this study, we addressed these challenges by proposing a regression-based approach to estimate large-scale grassland canopy cover, leveraging the integration of drone imagery and multisource remote sensing data. Specifically, over 90,000 10 × 10 m drone image tiles were collected at 1,255 sites across China. All drone image tiles were classified into grass and non-grass pixels to generate ground-truth canopy cover estimates. These estimates were then temporally aligned with satellite imagery-derived features to build a random forest regression model to map the grassland canopy cover distribution of China. Our results revealed that a single classification model can effectively distinguish between grass and non-grass pixels in drone images collected across diverse grassland types and large spatial scales, with multilayer perceptron demonstrating superior classification accuracy compared to Canopeo, support vector machine, random forest, and pyramid scene parsing network. The integration of extensive drone imagery successfully addressed the scale-mismatch issue between traditional ground measurements and satellite imagery, contributing significantly to enhancing mapping accuracy. The national canopy cover map of China generated for the year 2021 exhibited a spatial pattern of increasing canopy cover from northwest to southeast, with an average value of 56 % and a standard deviation of 26 %. Moreover, it demonstrated high accuracy, with a coefficient of determination of 0.89 and a root-mean-squared error of 12.38 %. The resulting high-resolution canopy cover map of China holds great potential in advancing our comprehension of grassland ecosystem processes and advocating for the sustainable management of grassland resources.

Plant extract mediated in-situ synthesis of iron/manganese alginate hydrosphere and its excellent recovery of rare earth elements in mine wastewater

The recovery of rare earth elements (REEs) is a major issue based on environmental governance and sustainable resource utilization. In this study, we developed a novel hydrogel material (Fe/Mn@ALG) by anchoring Fe/Mn NPs on alginate spheres, where Fe/Mn NPs were in-situ synthesized using Euphorbia cochinchensi leaf extract as reduced and protection agents. The Fe/Mn@ALG was applied directly to real mine wastewater, generating efficient and selective recovery of REEs with the coexistence of numerous competing metal ions. As results have shown, Fe/Mn@ALG was a useful adsorbent for REEs with an adsorption efficiency 78.62 % achieved, which was also confirmed by distribution coefficients (Kd), up to 2451.66 mL·g−1. Furthermore, Fe/Mn@ALG exhibited preferential response to REEs over other metal ions with the separation factor (SF) being up to 240. This great adsorption performance and selectivity toward REEs were attributed to its specific surface area, oxygen-rich functional groups and negatively charged surface in acid wastewater. Furthermore, REEs could be greatly desorbed from Fe/Mn@ALG with output concentration being three times higher than the initial concentration. Additionally, Fe/Mn@ALG maintained its good adsorption performance with efficiency reaching 72.24 % after five reuses. Overall, Fe/Mn@ALG can be considered as a promising candidate for wastewater remediation and sustainable management of resources.