Search Results (174)

Background: Small Island Developing States (SIDS) face high rates of non-communicable diseases (NCDs), and a key structural driver includes SIDS’ heavy reliance on imported food. Yet, our knowledge about food sources in SIDS is limited. Methods: We systematically searched 14 peer-reviewed databases and 17 grey literature repositories, identifying 56 articles and 96 documents concerning food sources in SIDS. Our study aimed to map these sources while considering broader societal, cultural, and environmental aspects. Results: We found high heterogeneity of food sources beyond store-bought foods, highlighting the complexity of food landscapes in this context. To explore these food sources and their interconnections, we developed a classification including Aid, Buy, Grow, Share, State and Wild food sources, and offered contextually-sensitive insights into their variety (types), extent (relevance), nature (characteristics) and changes over time. We developed an interactive open-access evidence map that outlined the identified interconnections between food sources following our proposed classification. There are numerous interrelations between food sources, showing that pathways from food sourcing to consumption can be unexpected and complex. Conclusions: In 2014, SIDS governments collectively committed to ending malnutrition by 2030. A deeper understanding of food sourcing is essential to achieve this goal. Full article

The COVID-19 pandemic revealed long-standing vulnerabilities in island tourism economies such as Crete and Chios, including seasonality, overdependence on mass tourism, and limited innovation adoption. This study investigates how sustainable tourism, regional development, and innovation interconnect in these two cases. Drawing on structured questionnaires addressed to tourism stakeholders in Hersonissos (Crete) and Chios, we apply a comparative analysis through descriptive and inferential statistics. The findings reveal a common interest in diversifying tourism offerings through digital transformation and alternative tourism models. Hersonissos demonstrates higher engagement with innovation-led strategies, while Chios reflects a cautious but growing inclination toward eco-tourism and cultural tourism initiatives. The study employs a comparative cross-sectional design based on structured questionnaires addressed to 71 tourism stakeholders in Hersonissos and Chios. Data were collected through purposive sampling that was completed in July 2023. As a practical outcome, we propose the Regional Innovation Index in Tourism—a composite tool designed to assess innovation readiness at the local level. This index enables policymakers to evaluate the strategic capacity of tourism regions and supports the formulation of long-term, place-based development strategies aligned with EU policy goals and the transition to a green economy. Full article

With the development of modern power systems, AC distribution networks face increasing demands for supply flexibility and reliability. Energy storage-based soft open points (E-SOPs), which integrate energy storage systems into the DC side of traditional SOP connecting AC distribution networks, not only maintain power flow control capabilities but also enhance system supply performance, providing a novel approach to AC distribution network fault recovery. To fully leverage the advantages of E-SOPs in handling faults in flexible interconnected AC distribution networks (FIDNs), this paper proposes an E-SOP-based FIDN islanding recovery method. First, the basic structure and control modes of SOPs for AC distribution networks are elaborated, and the E-SOP-based AC distribution network structure is analyzed. Second, with maximizing total load recovery as the objective function, the constraints of E-SOPs are comprehensively considered, and recovery priorities are established based on load importance classification. Then, a multi-dimensional improvement of the dung beetle optimizer (DBO) algorithm is implemented through Logistic chaotic mapping, adaptive parameter adjustment, elite learning mechanisms, and local search strategies, resulting in an efficient solution for AC distribution network power supply restoration. Finally, the proposed FIDN islanding partitioning and fault recovery methods are validated on a double-ended AC distribution network structure. Simulation results demonstrate that the improved DBO (IDBO) algorithm exhibits a superior optimization performance and the proposed method effectively enhances the load recovery capability of AC distribution networks, significantly improving the self-healing ability and operational reliability of AC distribution systems. Full article

An urban heat island (UHI) refers to urban areas that experience higher temperatures due to heat absorption and retention by impervious surfaces compared to the surrounding rural areas. Urban wetlands are crucial in mitigating the UHI effect and improving climate resilience via their cooling effect. This study examines Colombo, Sri Lanka, the RAMSAR-accredited wetland city in South Asia, to assess the cooling effect of urban wetlands based on 2023 dry season data for effective sustainable management. We used Landsat 8 and 9 data to create Land Use/Cover (LUC), Land Surface Temperature (LST), and surface-reflectance-based maps using the Google Earth Engine (GEE). The Enhanced Vegetation Index (EVI), Modified Normalized Difference Water Index (mNDWI), topographic wetness, elevation, slope, and impervious surface percentage were identified as the influencing variables. The results show that urban wetlands in Colombo face tremendous pressure due to rapid urban expansion. The cooling intensity positively correlates with wetland size. The threshold value of efficiency (TVoE) of urban wetlands in Colombo was 1.42 ha. Larger and more connected wetlands showed higher cooling effects. Vegetation- and water-based wetlands play an important role in <10 km urban areas, while more complex shape configuration wetlands provide better cooling effects in urban and peri-urban areas due to edge effects. Urban planners should prioritize protecting wetland areas and ensuring hydrological connectivity and interconnected wetland clusters to maximize the cooling effect and sustain ecosystem services in rapidly urbanizing coastal cities. Full article

Island communities that depend on mainland grid connections face substantial risks when natural disasters sever undersea or overhead cables, often resulting in long-lasting outages. This paper presents a comprehensive and novel two-part methodological framework for enhancing the resilience of these communities through networked microgrids that interconnect local renewable energy resources and battery storage. The framework integrates techno-economic capacity optimization using HOMER Pro with agent-based simulation in AnyLogic to determine cost-effective solar and storage capacities and to model dynamic real-time dispatch under varying conditions. Six island communities across three Indonesian provinces serve as illustrative case studies, tested under best-case and worst-case disruption scenarios that reflect seasonal extremes of solar availability. Simulation results reveal that isolated expansions of PV and battery storage can ensure critical residential loads, though certain islands with limited resources continue to experience shortfalls. By contrast, networked microgrids enable surplus power transfers between islands, significantly reducing unmet demand and alleviating the need for large-scale, individual storage. These findings demonstrate the significant potential of clustered microgrid designs to improve reliability, lower operational costs, and facilitate secure energy supply even during prolonged cable outages. The proposed framework offers a scalable roadmap for deploying resilient microgrid clusters in remote regions, with direct policy implications for system planners and local stakeholders seeking to leverage renewable energy in high-risk environments. Full article

Islanded microgrids commonly use droop control methods for autonomous power distribution; however, this approach causes system frequency deviation when common loads change. This deviation can be eliminated using secondary control methods, but the core of this approach is to generate compensation values equal to the offset amount to add to the controller, thereby eliminating deviations from rated values. Such a mechanism can actually achieve the same effect by setting power reference values within the droop control method. The power references within the controller need to be adjusted dynamically, and they are associated with common load variations. Therefore, establishing a fitting relationship between the adjustment of power reference and changes in common loads can achieve better frequency regulation, keeping the system frequency operating within rated frequency ranges. These two types of data are correlated, however, due to physical parameters, the fitting between them is not strictly fixed in a mathematical sense. Thus, to find their interconnected relationships, using intelligent methods becomes crucial. This paper proposes a shallow neural network-based method to achieve fitting relationships. Moreover, to address power inputs with zero values, an input enhancement method is proposed to prevent potential gradient vanishing and ineffective learning problems. Thus, through precise matching between power commands and load consumption, the system frequency can be maintained near rated values. Various simulation scenarios demonstrate the feasibility and effectiveness of the proposed method. Full article

The transition to 100% renewable energy systems is critical for achieving global sustainability and reducing dependence on fossil fuels. Island power systems, due to their geographical isolation, limited interconnectivity, and reliance on imported fuels, face unique challenges in this transition. These systems’ vulnerability to supply–demand imbalances, voltage instability, and frequency deviations necessitates tailored strategies for achieving grid stability. This study conducts a systematic review of the technical and operational challenges associated with transitioning island energy systems to fully renewable generation, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. Out of 991 identified studies, 81 high-quality articles were selected, focusing on key aspects such as grid stability, energy storage technologies, and advanced control strategies. The review highlights the importance of energy storage solutions like battery energy storage systems, hydrogen storage, pumped hydro storage, and flywheels in enhancing grid resilience and supporting frequency and voltage regulation. Advanced control strategies, including grid-forming and grid-following inverters, as well as digital twins and predictive analytics, emerged as effective in maintaining grid efficiency. Real-world case studies from islands such as El Hierro, Hawai’i, and Nusa Penida illustrate successful strategies and best practices, emphasizing the role of supportive policies and community engagement. While the findings demonstrate that fully renewable island systems are technically and economically feasible, challenges remain, including regulatory, financial, and policy barriers. Full article

Air pollution poses a significant challenge to environmental sustainability and inhibits economic and social development. In urban areas, the combined effects of high population density, industrial concentration, and the urban heat island effect make pollution control even more complex and demanding. Most studies on urban air pollution focus on specific pollution sources or localized areas, lacking a systematic approach tailored to the unique environmental conditions of megacities. Herein, this study employs bibliometric analysis based on the Web of Science (WOS) Core Collection, incorporating 3109 research articles on urban air pollution, including metropolitan areas and megacities, published between 2000 and 2024. By constructing a knowledge framework, this research reveals the thematic networks and evolutionary trends in the air pollution field. The findings indicate that key research themes, such as aerosols, air quality, and urban heat islands, have emerged as focal points. These themes, while relatively distinct, are interconnected, forming a three-dimensional framework of pollutants–health effects–monitoring, and governance. Moreover, the disciplinary network exhibits a clear convergence trend, with a shift from single-discipline studies to a more interdisciplinary approach. In terms of international collaboration, a bipolar structure led by the United States and China has taken shape. Through a multidimensional analysis of urban air pollution, this study identifies research hotspots and highlights the critical role of interdisciplinary and international cooperation in advancing urban air pollution control. By addressing the gap in cross-disciplinary, multi-perspective research, this work enhances the overall understanding of urban environmental policies and provides valuable insights for promoting global urban sustainability. Full article

We model and describe the combined effect of a series of urban heat islands (UHIs), generated by nearby cities aligned as an archipelago, on the vertical diffusion of heat and the temperature structure in the lower atmosphere over an urban chain in northwestern Morocco. We use the Weather and Forecasting Model (WRF) coupled to an urban canopy model to run simulations during the northern summer. We show that when the land surface is characterized accurately, the WRF model can effectively resolve the scale of the urban archipelago effect and describe its detailed diurnal structure. Our results indicate that the combined effect of multiple UHIs in proximity is more impactful than the sum of their parts. Specifically, the urban archipelago’s effect alters the vertical temperature structure through upward diffusion of heat and extends its scale from local to meso-scale. This alters the wind pattern and may affect local weather conditions and air quality. These results underline the importance of considering the urban archipelago effect when studying urban climate. They also extend beyond academic research to offer valuable insights for urban planners in emphasizing the importance of urban typology and spatial proximity in city design and balancing cities’ interconnectivity with sustainable development and resilience. Full article

Trees in urban environments play a crucial ecological role, helping to mitigate air pollution, reduce urban heat islands, improve stormwater drainage, and provide essential ecosystem services such as biodiversity conservation. Street trees, in particular, form an interconnected network within the urban fabric, offering the potential to link various green spaces across the city. Several cities have implemented dedicated Street Tree Master Plans (STMPs) to manage street trees effectively. A STMP thus serves as both a vital tool for the management and conservation of urban tree heritage and an opportunity to enhance public spaces and the quality of life for citizens. This case study of Rome (Italy) presents a particularly complex challenge, partly due to the city’s rich historical heritage, where street trees contribute to the identity of places and the urban environment in the context of climate change. The tree heritage of Rome requires ongoing maintenance, the improvement of growing conditions, the replacement of hazardous or aging trees along street rows, and the addition of new trees to enhance and diversify the urban tree population. Starting from a new census of street trees and a spatial analysis using GIS methodologies, this study examines the approach taken by Rome’s STMP. It focuses on the different strategies proposed for various types of streets, classified on the specific role that trees play in each context. Specifically, the plan offers a strategic vision for the city’s future, rooted in its urban form and supported by a methodological framework for planning interventions based on the current condition of tree cover. Drawing on insights from the STMP, the findings emphasize that any comprehensive renewal of street trees in large cities with historically significant and aesthetically rich landscapes must be guided by a strategic vision. In the discussion, a comparative analysis was conducted on different STMPs in various cities around the world, and we questioned how significantly historical and spatial considerations, which characterized the formation of Rome’s STMP, should be part of all STMPs. Full article

The energy transition of Cyprus presents a distinctive case study influenced by its geographic isolation, regulatory evolution, and the imperative to integrate renewable energy sources (RESs). This paper critically examines the chronological progression of Cyprus’ energy transition, beginning with the formulation of a liberalized electricity market aligned with the European Union’s Target Model. The analysis explores key drivers underpinning increased RES investments, while addressing the transformative impacts of global disruptions on energy security and policy priorities. Furthermore, it assesses pivotal regulatory reforms and the advancement of enabling infrastructure, such as advanced metering systems and cross–border interconnections, which underpin the island’s energy modernization efforts. Finally, this paper identifies opportunities for Cyprus to position itself as a regional smart energy hub, offering valuable insights into the challenges and prospects faced by isolated energy systems within the context of the European energy transition. Full article

The European rabbit (Oryctolagus cuniculus) presents a significant conservation and management challenge in Greece. While it has been listed in national biodiversity assessments, its population dynamics on the island of Lemnos demonstrate the characteristics of a highly adaptable and rapidly expanding species, exerting substantial ecological and economic impacts. Addressing this issue requires a spatially explicit understanding of its distribution patterns and habitat preferences, particularly given its extensive population growth over the past three decades. To this end, we conducted 40 field surveys across the island, documenting 1534 presence records of the species. We applied Kernel Density Estimation, Getis-Ord Gi *, and Anselin Local Moran’s I to identify the spatial distribution patterns and significant hotspots. A spatial lag model was used to quantify hotspot intensity and clustering dynamics, while abiotic, biotic, and anthropogenic factors were analyzed to assess habitat associations. Our results revealed that rabbit hotspots are predominantly concentrated in fertile lowland agroecosystems, with nearly 60% of high-density areas overlapping conservation zones. Soil and field conditions, grazing-supporting landscapes, and arable and subsidized agricultural areas emerged as significant predictors of O. cuniculus presence. The observed spatial dependencies indicated that while hotspot intensities and clustering dynamics are influenced by the conditions in neighboring areas, habitat characteristics remain fundamental in shaping their distribution, highlighting the broader landscape-scale spatial patterns affecting rabbit populations. These findings underscore the necessity of adopting spatially informed management strategies that mitigate agricultural impacts while accounting for interconnected spatial dynamics, providing a foundation for informed decision-making to manage rabbit populations while balancing conservation and agricultural priorities. Full article

The transition to inverter-dominated power systems with novel control strategies has created weak grid scenarios, prompting extensive research into grid-forming (GFM) converters and advanced GFM control schemes. This study evaluates two GFM control strategies for their stabilizing effects in weakly interconnected and islanded power systems: the established Virtual Synchronous Machine (VSM) control and the newly developed Phase-Restoring Principle (PRP). The evaluation is conducted using a real-time electromagnetic transient (EMT) simulation testbed with Hardware-in-the-Loop (HiL) capabilities. The system includes a multi-terminal medium-voltage (MVDC) and high-voltage direct current (HVDC) network weakly coupled to a network equivalent, represented by a scaled synchronous machine (SynM) to replicate grid inertia. Modular multilevel converters (MMCs) model the converters, while Power Hardware-in-the-Loop (PHiL) experiments integrate real power hardware. Dynamic interactions, including islanded conditions, are emulated to assess the performance of GFM controls and their interactions in HV/MV and AC/DC systems. The results demonstrate the compatibility of diverse GFM schemes with grid-following controls and synchronous machines, emphasizing their positive contributions to system stability. This modular demonstrator, as a realistic prototype of future power systems, provides a flexible platform for testing emerging GFM strategies and hardware, supporting the development of robust and stable inverter-based grids. Full article

Protected sites managed by indigenous people have been used for decades to conserve natural resources. These sites can be considered “conservation islands” and can maintain high biodiversity. This study explores the diversity and structure of medium and large mammals in (1) four protected natural areas in Oaxaca, Mexico, and (2) two different conservation strategies: one protected natural area (PNA) and three Voluntary Conservation Areas (VCAs). Data from 30 camera traps installed by community monitoring between 2013 and 2019 were used. A total of 29,304 camera days were accumulated in the Central Valleys and the Western Mountains and Valleys province. A total of 60,725 photographic records were analyzed, resulting in 13,471 independent events. Twenty-four species of wild mammals were documented, including endangered species. VCA showed higher species richness compared to PNA. Odocoileus virginianus was the most dominant in PNA, while Dicotyles angulatus was most dominant in VCA. We found differences in species richness between the four sites and between the two conservation strategies. Both conservation strategies are effective in maintaining mammal richness. We consider that these sites can serve as conservation islands that, in turn, can inter-connect landscapes and serve as potential biological corridors. Full article

In recent years, the growth of utilizing rural microgrids (RMGs) has been accompanied by various challenges. These necessitate the development of appropriate models for optimal generation in RMGs and RMGs’ coordination. In this paper, two distinct models for RMGs are presented. The first model includes an islanded rural microgrid (IRMG) and the second model consists of three RMGs that are interconnected with one another and linked to the distribution network. The proposed models take into account the uncertainty in load, photovoltaics (PVs), and wind turbines (WTs) with consideration of their correlation by using a scenario-based technique. Three objective functions are defined for optimization: minimizing operational costs including maintenance and fuel expenses, reducing voltage deviation to maintain power quality, and decreasing pollution emissions from fuel cells and microturbines. A new optimization method, namely the Improved Multi-Objective Crow Search Algorithm (IMOCSA), is proposed to solve the problem models. IMOCSA enhances the standard Crow Search Algorithm through three key improvements: an adaptive chaotic awareness probability to better balance exploration and exploitation, a mutation mechanism applied to the solution repository to prevent premature convergence, and a K-means clustering method to control repository size and increase algorithmic efficiency. Since the proposed problem is a multi-objective non-linear optimization problem with conflicting objectives, the idea of the Pareto front is used to find a group of optimal solutions. To assess the effectiveness and efficiency of the proposed models, they are implemented in two different case studies and the analysis and results are illustrated. Full article