Search Results (529)

Vegetated coastal wetlands, especially mangroves, seagrass beds, and salt marshes, are biodiversity-rich ecosystems whose blue carbon outcomes depend on living communities, sediment dynamics, hydrological connectivity, and landscape context. Biodiversity conservation and blue carbon management are often assessed through separate scientific, monitoring, and policy frameworks. This review uses a staged literature search and thematic synthesis to examine biodiversity–blue carbon linkages across the three major vegetated coastal wetland types. It considers how taxonomic, genetic, functional, and habitat diversity influence productivity, sediment stabilization, trophic exchange, carbon stocks, carbon burial, and carbon retention. It also evaluates how climate change, habitat fragmentation, hydrological alteration, pollution, and anthropogenic disturbance weaken these linkages. The synthesis compares representative carbon-stock and burial-rate baselines, examines conservation and restoration synergies and trade-offs, and expands the discussion of seagrass regime shifts. Field surveys, remote sensing, unmanned aerial vehicles, environmental DNA, and AI-enabled data integration are placed within a tiered monitoring framework. The review further develops an operational decision pathway for biodiversity-centered blue carbon management. Persistent blue carbon benefits arise where conservation and restoration maintain native communities, hydrological exchange, sediment stability, habitat complexity, migration space, and long-term stewardship capacity. Full article

The aim of this systematic literature review was to analyse how hydrological–hydraulic modelling, through the assessment of surface stormwater runoff behaviour, can support the participatory management of socio-environmental risks such as flooding, flash floods, and landslides. For this, 31 publications dating from 2015 to 2025 were selected from Scopus, ScienceDirect and Web of Science databases, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) guidelines, to examine the importance of integration between modelling and community participation for risk management. The results indicate that, despite recent advances, most studies still prioritise either the technical application of modelling or community participation, without articulating the two approaches in risk analysis and management processes. There is a scarcity of methods that effectively combine local knowledge into the collaborative construction of scenarios and in the continued use of modelling as a tool for monitoring flood risks to disseminate community information. It was observed that studies carried out in developing countries use simpler methods, using community participation as an alternative to the absence of data. In developed countries, however, studies use more advanced methodologies through institutionalised processes. In contexts marked by high vulnerability, the integration of community participation and technical tools, such as hydrological–hydraulic modelling, represents a promising pathway toward more equitable and efficient risk management practices, aligning with sustainability agendas such as the Sustainable Development Goals (SDGs). Full article

Surface oscillation is an important mechanism for the hydrological self-regulation of mires: it prevents the attenuation of flooding by storing water during high precipitation events and snowmelt. To investigate the spatial and temporal variability in surface oscillation, we conducted monthly measurements of the surface elevation and water level at three monitoring sites in the Great Vasyugan Mire (GVM), Western Siberia, over a nine-year period (2017–2025). Surface oscillation in the GVM varied from 14 to 25 cm in winter and early spring as a result of frost heaving, and from 2 to 16 cm in the frost-free period. Surface oscillation depends on the water table level variation, which is disturbed when the water level rises above the surface during freezing–thawing periods and due to released biogenic gases. Our data showed that within large mire systems, such as the Great Vasyugan Mire, the spatial variability in surface oscillation is influenced by several key factors: the type of plant community, peat properties, and the location relative to water flow pathways. Surface oscillation increased along a transect extending from the sedge–Sphagnum community to the pine–dwarf shrub–Sphagnum community, which runs parallel to the slope toward the marginal area. Long-term records demonstrate an increasing trend in surface elevation in the central part of the GVM, while showing a decrease at the mire boundary. Full article

Atmospheric wet deposition represents a major pathway for the transfer of organic micropollutants into terrestrial and aquatic ecosystems. This study investigates the occurrence and spatial distribution of polycyclic aromatic hydrocarbons (PAHs), phthalate esters (PAEs), and BTEX compounds in rainwater across Northern Serbia (Vojvodina region). Rainwater samples were collected during the 2025–2026 heating season at three locations: a petrochemical site in Kikinda, a traffic- and residentially influenced site in Sremska Mitrovica, and an urban background site in Sombor. Total concentrations showed pronounced spatial variability, with the highest ΣBTEX and ΣPAE levels recorded in Kikinda (∑BTEX = 2.818 μg L^∑1; ∑PAE = 0.930 μg L^∑1). Diagnostic ratios identified a dominant petrogenic signature in Kikinda (LMW/HMW > 1), while pyrogenic sources prevailed in Sremska Mitrovica and Sombor ((Fla/Fla + Pyr) > 0.5). BTEX profiles across all sites were characterised by the absence of benzene and elevated toluene and xylene levels (B/T ≈ 0; T/X > 1). Health risk assessment indicated an acceptable but non-negligible carcinogenic risk from PAHs, particularly for children in industrial areas. These findings highlight the role of precipitation as an efficient scavenger of organic pollutants and emphasise the need for integrated atmospheric–hydrological monitoring frameworks in industrialised regions. Full article

Urban flood vulnerability is increasingly shaped by the interaction between climate change, urbanization, and spatial planning practices, particularly in Mediterranean metropolitan areas. This study develops an integrated GIS–AHP framework to assess the susceptibility component of flood vulnerability in the urban area of Thessaloniki, Greece. Using open-access geospatial data, ten indicators representing soil, hydrological, and environmental conditions are derived and spatially analyzed. The Analytic Hierarchy Process (AHP), based on expert judgment, is applied to estimate the relative importance of these indicators and to support their integration into a composite flood susceptibility index. The results reveal strong spatial heterogeneity, with high susceptibility concentrated in low-lying, densely urbanized areas and zones near drainage pathways. Among the examined factors, the Topographic Wetness Index emerges as the most influential, highlighting the persistent role of terrain-driven hydrological processes even in highly built environments. The proposed framework provides a transparent and transferable methodology for identifying flood-prone areas and supports evidence-based urban planning and climate resilience strategies. The findings contribute to the broader discussion on vulnerability and resilience in urban systems by linking spatial analysis with decision-support tools in a policy-relevant context. Full article

Under the dual constraints of global food security and ecological protection, conventional agriculture is hampered by low resource efficiency and sluggish environmental response. Crop digital twin technology establishes a dynamic virtual reality system that integrates crops, environment, and water to enable real-time interaction and optimization. Based on the existing literature, this paper reviews the concept, architecture, and core modules of this technology and summarizes its applications in precision irrigation and crop monitoring. There are three major bottlenecks that persist, including limited high-frequency multi-source sensing and spatiotemporal fusion, insufficient parameter calibration and dynamic updating, and weak cross-scale integration from plant to watershed. Water is increasingly recognized as the key constraint and control variable and acting as both the central physiological driver of crop growth and the mass-flow link that connects the soil–plant–atmosphere continuum. The spatiotemporal dynamics of crop water deficit, compensatory root water uptake, evapotranspiration feedback, and the hydraulic behavior of irrigation-district canal systems constitute the core hydrological processes that must be simulated within the digital twin. Synchronizing crop water demand, soil moisture dynamics, atmospheric evapotranspiration, and irrigation scheduling within a unified spatiotemporal framework establishes a complete sensing, diagnosis, prediction and regulation technical chain. This chain offers a core pathway for alleviating agricultural water scarcity, improving irrigation efficiency, and ensuring food security. Full article

Groundwater contamination by redox-sensitive elements (RSEs) such as arsenic (As), chromium (Cr), vanadium (V), and selenium (Se) pose a critical challenge in alluvial aquifers, where seasonal hydrological forcing drives dynamic hydrogeochemical and redox conditions. This study investigates the seasonal evolution of groundwater hydrogeochemistry and multi-metal behavior in shallow aquifers of the Mid-Gangetic Plain, India, with particular emphasis on the role of seasonal redox decoupling. Monsoon conditions were dominated by strongly reducing environments (ORP: −150 to −70 mV), predominantly Ca–Mg–SO₄ and Na–Cl type facies. Under these conditions, significant correlations among RSEs in particular (As–V, As–Se) indicated coupled mobilization governed by the reductive dissolution of Fe–Mn (oxyhydr)oxides. Monsoon groundwater also exhibited strong associations between RSEs and agronomic indicators (NO₃⁻, SO₄²⁻), suggesting the influence of recharge-mediated agricultural inputs on redox-sensitive geochemical processes. In contrast, post-monsoon conditions showed a clear transition to sub-oxic states (ORP up to +121 mV) and were dominated by Ca–Mg–HCO₃ facies, accompanied by substantial increases in bicarbonate (~372%), electrical conductivity (~62%), and total dissolved solids (~21%). Despite the partial oxidation of the aquifer system, redox-sensitive metals did not respond uniformly. Instead, inter-element correlations weakened or disappeared, indicating a transition from coupled to decoupled contaminant behavior. Arsenic concentrations increased up to 20.8 µgL⁻¹, whereas Cr and V displayed variable enrichment controlled by alkali-induced desorption and carbonate-mediated surface interactions. This transition reflects seasonal redox decoupling, whereby seasonal redox shifts lead to metal-specific rather than coordinated multi-metal behavior. We propose a Seasonal Redox Decoupling Framework (SRDF) to explain the shift from coupled reductive release during monsoon conditions to selective mobilization pathways in the post-monsoon period. These findings demonstrate that seasonal redox shifts control not only metal concentrations but also inter-element relationships, leading to metal-specific risk profiles. This underscores the need for seasonally adaptive monitoring and management strategies in hydrologically dynamic alluvial aquifers. Full article

Extreme rainfall can rapidly alter hydrological connectivity in managed urban aquatic systems, yet its association with microbial community reassembly remains insufficiently understood. In 2025, Beijing experienced an anomalous rainy season with extreme rainfall, providing a single-year natural opportunity to examine bacterial and fungal communities across a dry–rainy–dry hydrological sequence in a managed river–pool system at the China National Botanical Garden (Northern Garden). Using 16S rRNA gene and ITS amplicon sequencing, we analyzed in situ water samples together with rainfall and runoff inflow samples representing atmospheric and catchment-derived external inputs. Bacterial alpha diversity increased during the mid-rainy phase influenced by extreme rainfall, whereas fungal alpha diversity remained comparatively stable despite compositional turnover. Genus-level profiles revealed distinct event-based source signatures—rainfall samples were characterized by Acinetobacter and Massilia, whereas runoff inflow samples were enriched in Arcobacter, Segatella, and Plectosphaerella. Null model analysis indicated that microbial assembly was dominated by stochastic processes, with bacterial communities mainly associated with drift-related undominated processes and fungal communities showing stronger dispersal limitation. Co-occurrence networks suggested rainfall-associated expansion of bacterial associations and persistently modular fungal networks. These findings suggest that extreme-rainfall-induced hydrological pulses are associated with divergent bacterial and fungal reassembly pathways in managed urban aquatic systems. Full article

Flooding is one of the most common and destructive natural disasters worldwide, and projections indicate that its intensity will increase across various climate regions during this century. South Sudan is particularly vulnerable due to a combination of factors, including hydrological releases from Lake Victoria, local rainfall patterns, and wetland retention dynamics. These factors raise important questions regarding the hydrological connectivity between Lake Victoria and the Nile system. This study examined how upstream hydrological conditions impact flood dynamics in South Sudan’s flood-prone regions, specifically in the states of Jonglei and Unity along the River Nile. To statistically estimate flood propagation lag time from Lake Victoria to the Sudd wetland, we used Cyclone Global Navigation Satellite System (CYGNSS) remote sensing data and water-level altimetry from both Lake Victoria and the River Nile at Mangalla. The analytical methods included moving block bootstrap (MBB) cross-correlation and Gaussian process (GP) modeling. Furthermore, we validated the event-based propagation and inundation patterns using flood event reports from the Displacement Tracking Matrix (DTM). The findings indicate that the statistical propagation signals took approximately 106 days during the wet season (95% confidence interval [CI]: 60–150 days) and 134 days during the dry season (95% CI: 75–195 days) for the downstream water level response to reach the River Nile at Mangalla, and 3–4 weeks to reach the adjacent floodplains downstream. Residual stationarity diagnostics showed augmented Dickey–Fuller (ADF) statistics below −7 across the analyzed propagation pathways, indicating statistically stationary lag-adjusted residual behavior. Consistent temporal correspondence between inferred flood arrival windows and independently reported DTM flood-impact periods provides cautious support for the hydrological plausibility of the estimated propagation structure. Full article

Aquatic environments that support tourism, including coasts, lakes, reservoirs, and estuaries, are experiencing accelerating eutrophication worldwide. This trend increases the frequency and intensity of algal blooms. These blooms undermine ecosystem services and weaken the socio-economic performance of destination areas. Despite these challenges, existing research remains fragmented. Aquatic sciences mainly examine nutrient enrichment and bloom dynamics. In contrast, tourism studies often treat blooms as episodic disturbances and rarely integrate exposure pathways, risk communication, or feedback to destination governance. This review synthesizes evidence across freshwater and marine systems to develop a coupled tourism–water ecosystem perspective. We link eutrophication drivers and bloom typologies to three dimensions. These are the degradation of tourism-supporting ecosystem services, compound health stressors, and communication filters. The first includes losses of water clarity and aesthetic value. The second involves multi-route exposure through contact, inhalation, and seafood ingestion. The third shapes perceived safety, trust, and behavioral adaptation. We further connect perceived health risks to observable tourist behaviors, including cancellation, destination substitution, and activity avoidance. These micro-level responses can aggregate into market-level demand contractions and consumption reallocation. They can also trigger regional economic cascades, including public management costs, employment impacts, and long-term reputational damage. Crucially, tourism is not merely a victim of blooms. It can also act as a reinforcing anthropogenic driver through wastewater burdens, infrastructure expansion, and pulse pressures. These pressures lower ecological resilience, especially under warming and hydrological stabilization. Finally, we identify governance leverage points. These include early-warning systems, threshold-based graded interventions, transparent risk communication, and integrated social–ecological modeling. These strategies can reduce uncertainty-driven losses and support adaptive destination management. Overall, this review reframes algal blooms as systemic social–ecological risks. It provides a structured basis for future empirical attribution and policy design in tourism-dependent waters under climate stress. Full article

This study assesses the future availability of water resources in Lake Guiers by 2050, considering the combined impacts of climate change and human activities, using the Water Evaluation and Planning System. As Senegal’s main freshwater source, the lake faces growing pressure from agricultural expansion, aquatic plant overgrowth, competing stakeholder demands, and increasing water use. The study combines field data on hydrological flows and agricultural water use with climate projections under the Shared Socioeconomic Pathways 4.5 and 8.5 scenarios. Climate data were downscaled and bias-corrected using CMhyd, multiple linear regression, and the Mann–Kendall test. Model calibration showed strong performance (NSE = 0.95; R² = 0.96). Results reveal decreasing precipitation and rising temperatures under both scenarios. Agricultural withdrawals (79,331,457.14 m³/year) already exceed crop water needs (69,115,088.03 m³/year), resulting in significant water losses estimated at over 10 million m³ per year. Scenario analysis indicates that high water demand under Shared Socioeconomic Pathways SSP8.5 could lead to critical declines in lake volume as early as 2026 (550 million m³), while moderate demand growth under SSP4.5 could maintain water availability until 2050. The proposed PREFERLO-Grand Transfer project would add further stress to the lake’s capacity. These findings emphasize the urgent need for sustainable water management and policy actions. Full article

The karst region of Southwest China represents a typical high geological background area characterized by extensive carbonate bedrock and secondary enrichment of heavy metals, particularly cadmium (Cd), in residual soils. Under natural carbonate-buffered conditions, Cd is largely immobilized through mineral associations and surface complexation, resulting in elevated total concentrations but low bioavailability. However, intensified anthropogenic pressures–including acid deposition, mining, excessive fertilization, and improper irrigation—have accelerated soil acidification in paddy fields. Acidification disrupts carbonate geochemical equilibria, weakens buffering capacity, and drives Cd speciation shifts toward more labile forms, thereby enhancing plant uptake and accumulation. These effects are especially pronounced in paddy fields and other systems subject to hydrological and redox fluctuations that further increase Cd mobility. To evaluate these coupled geogenic and anthropogenic controls, we conducted a structured literature synthesis (2016–2026) focusing on peer-reviewed studies of Cd dynamics in Southwestern China’s karst agroecosystems. We critically examine (i) the formation mechanisms and spatial heterogeneity of high-background Cd, (ii) acidification-driven speciation transformation and soil–crop transfer pathways, and (iii) in situ remediation and precision risk assessment strategies. By integrating geological inheritance, geochemical activation, and ecological risk perspectives, this review proposes a conceptual framework to support soil quality standard refinement and adaptive risk management in high-background karst regions. Full article

Climate change intensifies hydrological variability and threatens agricultural water security. This review synthesizes literature on agricultural water system resilience under climate change through a structured critical narrative approach informed by PRISMA/SALSA reporting principles. We examine four linked domains: resilience concepts and indicators, assessment methods under uncertainty, climate impact and vulnerability evidence, and adaptation/governance pathways. The synthesis indicates a broad shift from engineering-centered water-supply approaches toward socio-ecological resilience frameworks that combine infrastructure, ecosystem processes, farmer behavior, and institutions. Methodologically, deterministic optimization is increasingly complemented by stochastic, robust, integrated-assessment, remote-sensing, and machine-learning approaches, although data requirements, uncertainty propagation, and interpretability remain important constraints. Evidence suggests that crop water demand and irrigation requirements may increase substantially under high-emission scenarios, with acute risks in arid and semi-arid regions. Effective adaptation is unlikely to rely on single technologies alone; precision irrigation, nature-based solutions, climate services, and infrastructure investments require complementary demand-side rules, water accounting, equity safeguards, and participatory governance to avoid maladaptation such as the irrigation-efficiency rebound effect. We identify priority research needs in transparent review protocols, uncertainty quantification, cross-scale governance, farmer decision-making, digital inclusion, and monitoring systems. The review provides a moderated conceptual framework and policy-oriented research agenda for strengthening agricultural water resilience. Full article

Coastal reclamation reshapes tidal hydrodynamics in semi-enclosed bays by removing intertidal storage, modifying channel conveyance, and redistributing tidal exchange among connected sub-regions. This study quantifies the multi-decadal cumulative impacts of reclamation on tidal currents and tidal prism in Yueqing Bay, China, using shoreline and bathymetric reconstructions for 1978, 2002, 2013, and 2020; hydrological observations; and a two-dimensional MIKE21 FM tidal hydrodynamic model. Characteristic cross-sections were used to estimate bay-wide and sub-regional tidal prisms, and representative stations were used to diagnose current-speed responses. The bay-wide tidal prism decreased from 15.235 × 10⁸ m³ in 1978 to 12.316 × 10⁸ m³ in 2020, corresponding to a reduction of 2.919 × 10⁸ m³ (19.16%). The strongest loss occurred during 1978–2002, when large-scale reclamation and closure of the Xuanmen Channel removed tidal storage and redirected flow into the remaining main-channel system. Although reclamation intensity weakened after 2013, mean current speed still changed by −0.050 to 0.033 m/s and sub-regional tidal-prism shares continued to adjust, indicating delayed hydrodynamic reorganization rather than immediate stabilization. These results show that reclamation impacts cannot be explained by reclaimed area alone; they depend on project timing, spatial layout, and the connectivity with key tidal pathways. The findings support staged assessment and pathway-sensitive shoreline management in reclaimed semi-enclosed bays. Full article

Understanding how natural and anthropogenic factors jointly influence avian diversity is essential for biodiversity conservation and the sustainable management of large-scale wetland ecosystems, yet their combined effects remain insufficiently understood. This gap is particularly evident for land birds, as most studies focus on waterbirds. Using structural equation modeling, we quantified the effects of these drivers on habitat quality and avian richness in the Sanjiang Plain, separately for waterbirds and land birds. Our results show that: (1) habitat quality is primarily controlled by natural factors, particularly soil organic carbon (SOC), normalized difference vegetation index (NDVI), and topography, whereas human activities exert weak negative effects; (2) waterbirds are primarily associated with SOC- and temperature-driven pathways, whereas land birds respond more directly to climate and human disturbance; (3) natural drivers exert stronger effects than anthropogenic factors on both waterbird and land bird diversity; and (4) the effects of natural drivers differ between bird groups, with SOC and NDVI showing stronger effects on waterbirds, and precipitation and temperature being more influential for land birds. These findings highlight the need for group-specific conservation strategies, including conserving soil carbon and maintaining hydrological conditions for waterbirds, and enhancing vegetation and mitigating human disturbance for land birds. Full article