The Euphrates River Flooding Event of May–June 2026: Hydrological Analysis, Transboundary Water Management, and Institutional Dimensions

In late May 2026, the Euphrates River experienced a significant flooding event, with water levels rising approximately four meters in some locations. Water flows increased from normal levels of approximately 300–500 m³/s to peak releases of 1800 m³/s. The flood resulted from a confluence of extreme meteorological conditions—record rainfall across Syria and Türkiye, combined with rapid snowmelt in the Turkish highlands—and dam operations, including the first opening of the Atatürk Dam spillway gates in seven years and the first opening of the Euphrates Dam floodgates in approximately four decades. While the 2026 event was moderate by historical standards (smaller than the 1969 flood and the 1988 flood of 2760 m³/s at Husaybah), the opening of the Euphrates Dam floodgates after approximately 40 years was unprecedented in the post-dam era. This paper synthesizes available data on the event’s causes, impacts, and implications for transboundary water management, drawing on official statements from Syrian, Turkish, and Iraqi authorities as well as hydrological literature and multiple language sources. The analysis places the 2026 event within the broader context of the Euphrates River’s hydrological history, examining both historical flooding events and the multi-decadal drought patterns that have characterized the basin over the past century. The paper also identifies institutional instability in Syria’s water sector following the 2024 political transition as a potential contributing factor deserving investigation, while acknowledging that direct causal evidence remains limited. Based on these findings, the paper recommends improved transboundary coordination, infrastructure upgrades, and—subject to further investigation of the institutional hypothesis—reconstitution of Syria’s water management technical capacity to ensure future hydrological resilience.

Groundwater Systems, Aquifer Characterization, and Sustainability Challenges in Nigeria: A Scoping Review of Hydrogeological and Geophysical Investigations (2000–2026)

Groundwater represents one of the most important freshwater resources in Nigeria and serves as a major source of water for domestic, agricultural, and industrial activities. This scoping review synthesizes existing knowledge on groundwater systems, aquifer characterization, hydrogeophysical investigations, groundwater quality, and sustainability challenges across different hydrogeological environments in Nigeria. The review adopted the PRISMA-ScR framework and analyzed peer-reviewed studies published between 2000 and 2026, retrieved from Scopus, Web of Science, Google Scholar, ScienceDirect, and SpringerLink databases. The findings revealed substantial hydrogeological variability associated with the Basement Complex terrains, sedimentary basins, Coastal Plain Sands, and alluvial aquifer systems. Vertical Electrical Sounding (VES), Electrical Resistivity Tomography (ERT), hydrochemical analysis, GIS integration, and remote sensing emerged as the dominant groundwater investigation techniques. The review further identified increasing groundwater quality deterioration resulting from salinity intrusion, industrial pollution, oil spill contamination, excessive groundwater abstraction, and climate variability. Coastal aquifers within the Niger Delta, Lagos, and Akwa Ibom regions were found to be particularly vulnerable to seawater intrusion and hydrocarbon contamination. Despite increasing groundwater studies, major gaps remain in long-term monitoring, integrated hydrogeophysical investigations, and national groundwater database development. The study emphasizes the need for integrated groundwater management, sustainable policy frameworks, climate-resilient groundwater assessment approaches, and interdisciplinary research strategies to support long-term groundwater sustainability and water security in Nigeria.

Water–Energy–Food Nexus and Circular Economy Analysis of Melon (Cucumis melo L.) and Grape (Vitis vinifera L.) Value Chains: A Life Cycle, Water Footprint, and Exergy Assessment with Turkish Case Studies

This study applies an integrated water–energy–food (WEF) nexus approach to melon and grape value chains, combining life cycle assessment, water footprinting (blue/green/grey), carbon footprint, and exergy analysis within a circular economy framework. Türkiye, the fourth-largest melon producer (~1.7 Mt/yr) with over 80 indigenous grape cultivars, serves as the primary case study, supplemented by global data. In the wine chain, cultivation (37%) and glass packaging (28%) dominate global warming potential (GWP), with a baseline of 1.38 kg CO₂eq per 0.75 L bottle (ReCiPe 2016-H). Recovering pomace bioethanol, polyphenolic extracts, grape seed oil, and tartaric acid in a circular economy scenario lowers the footprint to 1.12 kg CO₂eq (−19%). Turkish wine grapes exhibit blue-water shares of 38–41%, well above the global 25%, reflecting irrigation reliance in semi-arid Anatolia (Elazığ, Diyarbakır, Cappadocia). Exergy analysis identifies refrigeration as the top energy sink (280 MJ/t grapes, 32%) and primary exergy destruction site (193 MJ/t; second-law efficiency: 31%). Fermentation records the lowest exergy efficiency (28%) due to the irreversibility of sugar-to-ethanol conversion. These findings demonstrate that combining WEF nexus management with circular bioeconomy strategies can substantially reduce the overall environmental burden, particularly in water-stressed agricultural regions.

Energy Effectiveness and Economic Competitiveness of Two Emerging Solar Space Heating Technologies

This study provides a comprehensive long-term energy performance evaluation comparing traditional solar space heating systems (water and air collectors) with emerging alternatives, namely photovoltaic (PV)-driven heat pumps and photothermal solar heat extractors. The comparison is performed per unit collection area under idealized heat use and storage assumptions, rather than as a full building-level heating system analysis. Utilizing hourly meteorological and radiometric data from Rock Springs, US (2001–2022), the results reveal that while solar water heat extractors are more efficient than traditional heaters, their heating gain factor remains below 1.2, whereas emerging solar air heat extractors demonstrate low future potential. Over annual cycles, crystalline silicon PV-driven heat pumps outperform traditional solar water heating due to their superior efficiency under the low-to-moderate solar irradiance levels that dominate the heating season, despite traditional systems performing better at peak heat fluxes. Ultimately, this underscores that long-term technology dominance is strictly non-linear and governed by local radiative climates. Complementing the technical study, a preliminary economic screening is performed based strictly on component capital costs, without factoring in long-term operational dynamics such as maintenance, degradation, or discounting. Within this simplified financial framework, the analysis indicates that crystalline silicon or CdTe PV-driven heat pumps can viably replace solar water collectors (unless domestic hot water is a primary requirement) or expensive closed-circuit air collectors. Conversely, solar heat extractors remain viable only in niche applications with exceptionally high thermal energy costs exceeding 0.25 USD/kWh. By establishing these boundary thresholds, this work provides a streamlined decision-making framework that identifies the economic domains in which emerging PV-heat pump configurations achieve market viability relative to traditional thermal systems.

Effects of Manipulating Water and Temperature on Soil Nematode Communities of Heterogeneous Karst Habitats in Southwest China

Global climates are rapidly changing and future climates are predicted to be characterized by extreme climatic events, especially prolonged drought and hot weather. In this study, we explored the effects of manipulated low and high soil water availability and soil temperature on soil food webs (as indicated by soil nematode communities) from contrasting soil habitats. Soils were collected from a relatively arid karst mountain peak, a relatively moist karst piedmont, and a mixed soil of these two was also tested. The results showed that water availability was the primary factor influencing the soil food web. Soil food web structures were mature under low water availability in mountain peak soils and under high water availability in piedmont soils. In the mountain peak soils, high water availability decreased the maturity index and structure index of soil nematodes, which was mainly due to marked increase in the absolute and relative abundances of low trophic level organisms (i.e., bacterivores and fungivores). In the Piedmont soils, high water supply increased the maturity index and structure index of soil nematodes, which mainly due to the increases in the absolute and relative abundances of higher trophic level nematodes, such as omnivores and predators. However, the nematode maturity index and structure index showed no significant response to variations in water availability when soils from the mountain peak and piedmont were mixed and cultured together. Although the overall effect of temperature on the soil nematode community was weaker than that of water availability, temperature exerted significant context-dependent effects. Particularly, moderate temperatures increased fungivorous nematode abundance under drought conditions in mountain peak soils but decreased it under moist conditions in piedmont soils. Notably, plant-parasitic nematodes showed no significant response to either soil moisture or temperature treatments across all soil types, indicating a high degree of stability in this trophic group under short-term fluctuations in water and temperature. Our results suggest that changes in precipitation may have stronger effects on soil nematode communities than increases in temperature. However, the interaction between temperature and moisture should not be overlooked, as it can shape nematode community composition in habitat-specific ways. In addition, drought-tolerant soil organisms may be available for improving the resistance of soil food webs to prolonged drought under climate change conditions.

What Should Ecology Study for Watershed?

Dynamic Thermal Performance of a Plate Heat Exchanger Under Viscosity–Velocity Combined: Implications for Seawater-Source Heat Pump Systems

To address the difficulty of predicting plate heat exchanger performance under variable-flow and fouling-prone coastal conditions, this study developed a novel combined framework for a BR50 plate heat exchanger by integrating a steady-state heat transfer model with a transfer-function-based dynamic wall-temperature model. The main innovation is that the framework simultaneously captures steady thermal performance and transient wall-temperature response, while explicitly quantifying the coupled effects of flow velocity and kinematic viscosity. The model was evaluated for sewage-side velocities of 0.8–1.5 m/s and viscosities up to ten times that of clean water. Results show that wall temperature increases slightly with velocity and can be described by a fourth-order polynomial. Its transient response follows first-order inertia, and the time constant decreases as velocity increases, indicating faster thermal response at higher flow rates. Both the sewage-side heat transfer coefficient and the overall heat transfer coefficient increase with velocity but decrease with viscosity; increasing velocity from 0.8 to 1.5 m/s raises the sewage-side coefficient by 49.2%. Sensitivity analysis identifies kinematic viscosity as the dominant factor affecting thermal performance, followed by flow velocity and wall temperature. The framework provides a practical basis for seawater-source heat pumps and coastal heat recovery systems under fouling-influenced conditions.

Impacts of Climate Variability and Change on Hydrological Dynamics in the Koliba-Corubal Basin (Guinea and Guinea-Bissau): Modelling Historical and Future Flows by GR4J under CMIP6 Climate Scenarios

The Koliba-Corubal basin, located between Guinea and Guinea-Bissau, is a key area for water resource management, but it is vulnerable to the effects of climate change. This article aims to analyze historical and future hydrological trends in this basin using the GR4J hydrological model in order to assess the impact of climate change on water availability. The study is based on past climate data (1981–1993) and future projections from CMIP6 climate models, applied to three climate change scenarios: SSP 126, SSP 370, and SSP 585. The results show a significant decrease in river flows in the basin, with reductions of up to 65.6% by the end of the century, especially under the SSP 370 and SSP 585 scenarios. Dry periods are especially affected, with a marked decline in monthly flows, seriously impacting water resource management for agriculture and drinking water supply. Using Mann-Kendall and Pettitt statistical tests, the study also identifies potential breaks in the time series of flows. The results of this analysis highlight the urgency of adopting climate change adaptation strategies and the need for sustainable water resource management in the Koliba-Corubal basin to meet the challenges posed by these changes.

Holdiversity (和多样性): An Integrative Concept Toward Sustainability

Facing the multiple challenges brought about by global change and social development, this paper proposes the conceptual framework of “Holdiversity (和多样性)”, which defines human diversity, biological diversity, and environmental diversity as an interdependent, co-evolving, coupled system. This approach aims to systematically comprehend the synergistic mechanisms between humans and nature, facilitating the construction of trade-off strategies for sustainable development. Furthermore, this paper proposes that the watershed can serve as a fundamental operational unit for Holdiversity research. Its distinct natural boundaries and hierarchical structure enable it to effectively carry the spatial superposition and feedback coupling of multiple diversities. This concept aims to provide an integrated framework for interdisciplinary research and to offer a novel perspective on implementing the United Nations Sustainable Development Goals (SDGs).

Immobilization Strategies of Cyclodextrins on Ferrimagnetic Nanoparticles for Dye Water Remediation: A Review

This paper provides a comprehensive review of the synthesis, use, and advantages of cyclodextrin-derivatized ferrimagnetic nanoparticles for the removal of textile dyes from natural waters. Dyes make their way into natural water systems and affect ecosystems and human health. Water soluble natural cyclodextrins (CD) are able to include dyes into their hydrophobic cavities. To extract the pollutant from water, the host molecules need to be tethered to insoluble supports, such as magnetic nanoparticles, making possible the extraction of the pollutant from the water using a simple magnet. Thus, after washing treatment, the pollutant is extracted, and the support is regenerated for a new remediation cycle. We report herein the synthetic strategies to immobilize β-cyclodextrin onto magnetic nanoparticles MNP@CD using weak to strong bindings, and the analytical methods used to characterize and monitor their effectiveness. Hydroxyl groups present on the CD scaffold can chelate iron cores by coprecipitation, solvothermal reaction, polymerization, carboxylic acid coordination, and silica bonding. An assessment of various dye adsorption capacities of MNP@CD is reported, spanning a range of 3 orders of magnitude, from 2.38 to 2780 mg of dye/g. The recyclability of the magnetic nanoparticles, with excellent removal rates of 90% after a few cycles, is also discussed.