Search Results (4,751)

The layout of urban blue, green and grey spaces plays a crucial role in flood risk, but the potential trade-offs and synergistic effects of these spaces on urban flood risk have not been fully studied. This research uses the spatial Durbin model to analyze the direct impact of changes in urban blue, green and grey spaces on risk changes and the spatial spillover effects, revealing how the balance and coordination states and their changes affect urban flood risk. The results show the following: (1) An increase in the balance effect is often accompanied by an increase in risk, but there are differences in the intensity and direction of response at different stages, and the risk changes show significant spatial dependence and spillover effects. (3) The analysis of the spatial Durbin model indicates that the increase in blue and green spaces mainly alleviates risks through local retention and storage. It is notable that in the later stage, the neighborhood spillover effect of green spaces has exceeded its direct local effect, highlighting the collaborative value of green network connectivity at the regional level; while the impact of grey spaces is the most complex—although the construction of sponge cities and urban rainwater management have led to a negative direct local effect (2020–2024), its positive neighborhood spillover effect still persists. Clearly understanding how “balance and coordination” affects risk at different development stages can help urban managers formulate differentiated strategies for the proportion of blue, green and grey spaces based on the development stage of the city, thereby avoiding the use of “one-size-fits-all” planning standards. Full article

The interplay between water-saving irrigation and potassium (K) management in regulating paddy methane (CH₄) emissions remains poorly understood. It remains unclear whether carbon pool enhancement induced by K fertilization could counteract the oxidation effects under non-flooded irrigation. Here, we conducted a field-based trial over two years to explore how irrigation regimes (continuous flooding, I_F; intermittent irrigation, I_I) and K application rates (K₀, K₇₅, K₁₅₀ kg ha⁻¹) modify soil redox status, carbon pools, crop growth, CH₄ emissions and economic benefits. Intermittent irrigation markedly elevated soil redox potential (Eh), suppressed dissolved organic carbon (DOC), and substantially reduced two-year average CH₄ emissions by 75.1–76.9%, regardless of K supply. Under I_F, high-rate K fertilization (K₁₅₀) stimulated cumulative CH₄ emissions; nevertheless, such K-driven CH₄ stimulation was completely offset under intermittent irrigation. Soil Eh, DOC and microbial biomass carbon (MBC) dominated CH₄ variation, among which Eh exerted the primary control. Intermittent irrigation combined with K fertilization improved rice grain yield. A comprehensive TOPSIS-Entropy multi-criteria evaluation identified the I_IK₇₅ treatment as the optimal option balancing environmental benefits and economic returns. Collectively, intermittent irrigation can mitigate the methanogenic risk from high potassium input, providing a promising redox-regulated strategy for low-CH₄ emission and high rice production. Full article

Contemporary approaches to urban water management increasingly rely on concepts such as Nature-Based Solutions (NBSs), Green Infrastructure, and Blue-Green Infrastructure. Although these frameworks have gained broad acceptance, their typological character provides limited guidance for project-oriented decision-making, as they primarily describe infrastructure types rather than their functions within integrated hydrological systems. To address this gap, this study proposes a complementary functional-operational framework for interpreting ecological infrastructures in urban flood mitigation. Employing a qualitative comparative case study methodology, we analysed four diverse international models—the Dutch Water Squares (Rotterdam), Tokyo’s underground flood control system, Copenhagen’s Cloudburst Management Plan, and Singapore’s ABC Waters Programme—to examine the systemic interaction between grey, green, and blue infrastructures at different watershed scales. The results indicate that flood mitigation effectiveness depends less on the predominance of a single infrastructure type and more on the functional coupling among them. Specifically, three primary functions were identified: rapid conveyance (grey infrastructure), infiltration and thermal regulation (green infrastructure), and dynamic storage and biodiversity support (blue infrastructure). Despite the contextual limitations and varying scales of the selected cases, blue infrastructure universally emerges as a systemic buffer that enhances urban resilience by regulating excess volumetric flows. Ultimately, the proposed framework introduces an actionable interpretative layer that complements existing typological classifications, providing planners and urban designers with a robust, scalable basis for implementing integrated ecological infrastructures. Full article

While low-impact development and retention strategies are widely studied in urban and agricultural contexts, a distinct knowledge gap remains regarding the quantitative evaluation of dispersed, natural microretention structures in small, ungauged, mountainous forested catchments under complex topographic conditions. To address this limitation, this study provides a novel quantitative assessment of how natural bioretention interventions—specifically arcuate deadwood log barriers, cascading reservoir systems, and strategic afforestation—influence runoff reduction and substrate infiltration dynamics. Focusing on the 4.57 km² basin of the Stankowice Stream in southwestern Poland, the research integrates field geodetic and hydrological measurements with Iszkowski’s empirical flow formulas and high-resolution digital elevation modeling (SCALGO platform). Delineation of 10 key subcatchments revealed that surface runoff potential is heavily concentrated within specific flow pathways rather than determined solely by subbasin area. In unit No. 9, deploying an arcuate arrangement of 19 deadwood logs achieved an 11% reduction in surface runoff (retaining 8662.50 m³), whereas coupling these log structures with a downstream cascading two-dam system significantly enhanced retention performance by establishing 79,065.68 m³ of depression storage and driving 264,066.16 m³ of subsurface infiltration. Furthermore, multi-scenario land use modeling demonstrated that transforming land cover to forest reduced surface runoff by over 70% in topographically steep subcatchments (e.g., unit No. 7). These findings demonstrate that effective flood mitigation in headwater catchments requires a systemic, targeted hybrid strategy combining decentralized bioretention with localized storage nodes, offering a transferable framework for sustainable regional water governance. Full article

Against the backdrop of global climate change, drought–flood abrupt alternation (DFAA) has become a major compound climate extreme threatening ecosystem stability and sustainable watershed management. This study investigated the spatiotemporal characteristics and ecological responses of DFAA in the Jialing River Basin, China, using meteorological and hydrological observations from 1971 to 2020. DFAA events were identified using the Standardized Weighted Average Precipitation Index (SWAP) and run theory, and their spatiotemporal heterogeneity was characterized using spatial autocorrelation analysis. The Long-duration DFAA Index (LDFAI) was derived using the WEP-L distributed hydrological model. Ecological responses during 2000–2020 were evaluated by integrating the Remote Sensing Ecological Index (RSEI), grey relational analysis, and a Copula-based conditional probability model. The results showed that drought-to-flood events exhibited stronger spatial clustering than flood-to-drought events. Ecosystem responses showed significant lag effects, averaging 6.9 months for spring–summer events and 5 months for summer–autumn events, with greater sensitivity during the summer–autumn period. Under DTF events, the probability of maintaining relatively high ecological quality was significantly higher than under FTD events, whereas FTD events were associated with a higher probability of ecological degradation. Under compound scenarios, consecutive same-type events were more conducive to ecosystem stability, while alternating sequences of different event types significantly amplified negative ecological stress and represented high-risk scenarios for ecological degradation. These findings provide scientific support for adaptive watershed management, ecological restoration, and climate change adaptation in drought–flood-prone regions. Full article

Understanding river channel evolution is essential for effective management, as lateral erosion shapes riverbeds, floodplains, and riparian habitats. Despite advancements in remote sensing, translating these technologies into operational tools for institutional monitoring remains a challenge. This study introduces a semi-automated framework designed to bridge this gap by quantifying lateral mobility and bank retreat rates in high-energy, gravel-bed rivers. The methodology utilizes a Random Forest classifier applied to Copernicus Sentinel-2 time series (2016–2024) across five rivers in Piedmont (Italy). By detecting pixel-level class shifts between water, vegetation, and sediment, the procedure provides a proxy for lateral mobility. Validated against 120 km of manual delineations, the model achieved high spatial accuracy for both bank retreat rates and eroded bank lengths measurements (Mean Absolute Deviation of 2.64 m/yr and 4.34%, respectively). Integrating discharge data and the hydraulic infrastructure cadaster of the Sesia River, the proposed framework effectively detects reaches prone to significant geomorphic changes, isolates their underlying drivers, simulates 10-year evolutionary trajectories, and demonstrates strong predictive capabilities regarding future channel–infrastructure interactions. This study marks a shift from sporadic, labor-intensive assessments to a dynamic, systematic monitoring framework. Leveraging free satellite data, it provides competent authorities with an objective, cost-effective tool to prioritize interventions, supporting flood risk reduction and river restoration. Full article

Recent efforts to address flooding have explored incorporating flow-reduction capabilities into existing infrastructure. Roadside ditches have historically been viewed as an underutilized component of flood reduction, and a two-stage design has been proposed that modifies a conventional trapezoidal ditch by incorporating bench insets along the main channel. While it is expected that this second stage becomes inundated during storm events, resulting in flow attenuation, the exact impacts of this design are unknown. This study quantified the impact of the two-stage design by modeling a roadside ditch corridor in eastern Iowa. An existing single-stage ditch was converted to a two-stage design, and a HEC-RAS model was constructed to investigate the ditch’s impacts for four design storms (1-year, 2-year, 5-year, and 10-year). In the modeled results, peak flow rates were reduced by 22%, 21%, 7.5%, and 4.3%, respectively, while water volume reductions were near 6%. Maximum velocities throughout the ditch corridor also decreased, with reductions spanning 32% (1-year)–45% (10-year). These results indicate that increased travel times and infiltration associated with the two-stage design provide hydrologic and hydraulic benefits by lessening flood and erosion risk. While further study is needed to verify this behavior through monitoring and modeling at other locations, our findings suggest that two-stage ditches can be a useful best management practice for the transportation community. Full article

Accurate nowcasting of high-intensity precipitation is critical for urban flood control and short-term hydrological risk management. However, the high stochasticity of convective systems poses a significant challenge for traditional deep learning models in generating accurate predictions. Existing regression-based models, often constrained by Mean Squared Error loss, tend to produce over-smoothed results, leading to severe underestimation of heavy rainfall centers. To address this challenge, this study proposes an event-guided two-stage nowcasting framework, named EGN-Nowcast, which incorporates intensity-aware auxiliary supervision through an implicit regularization strategy. This framework integrates an event-aware spatiotemporal Transformer with a Conditional Diffusion Refiner. Specifically, an event-aware auxiliary mechanism is introduced to increase the optimization emphasis on high-intensity precipitation regions. The conditional diffusion module then refines the coarse precipitation prediction to recover fine-scale structures while preserving the spatiotemporal consistency learned by the first-stage predictor. This strategy is designed to alleviate over-smoothing and improve spatiotemporal consistency under the evaluated KNMI radar setting. Experiments based on the KNMI radar dataset from 2016 to 2025 show improvements in several pixel-level, categorical, and visual verification metrics, including a reduction in the false alarm rate for high-intensity precipitation events (>8 mm/h). These results suggest that the proposed framework can improve the representation of localized high-intensity precipitation structures and reduce false alarms under sparse high-intensity precipitation conditions on the selected KNMI radar dataset. Full article

Floodplain lake ecosystems around the world have witnessed growing environmental degradation under combined natural climatic variability and anthropogenic activities. Reconstructing their long-term ecological change is vital for lake ecosystem conservation and management. Cladoceran subfossils are used as an important proxy indicator to reconstruct ecological evolution of floodplain lake systems worldwide. The sedimentary record of Zhangdu Lake, a shallow floodplain lake in the middle and lower reaches of the Yangtze River in China, is important for reconstructing more than 150 years of environmental history and tracing the lake ecosystem’s transition from a natural flood-pulse system to a new regime driven by anthropogenic disturbances. Integration of subfossil cladoceran data with other biological proxies (diatoms and testate amoebae) and physicochemical sedimentary proxies successfully identified the period of river–lake disconnection and the associated ecological processes and succession in Lake Zhangdu. An abrupt disconnection of the lake from the Yangtze River in the early 1950s led to a sudden ecological vulnerability together with a drastic community decline. Sequential t-test Analysis of Regime Shifts (STARS) identified cladoceran community shifts in 1966 and 1999, with regime shift index (RSI) values of 1.195 and 3.29, respectively, reflecting multi-phase ecological reorganization following the 1950s disconnection. Differences among the proxies in the timing and magnitude of change and in their apparent drivers reflected group-specific habitat preferences, response thresholds, and trophic positions. This study shows that the assessment of multi-taxa paleoecological indicators can provide a strong evidence base for guiding restoration efforts in degraded floodplain lake ecosystems in China and elsewhere. Full article

Changes in river channel morphology under the influence of natural and anthropogenic factors pose a serious threat to the stability of aquatic ecosystems and water resource use, especially in regions with limited hydrological information. This study presents, for the first time, a three-dimensional numerical investigation of channel processes in the Talas River (Kazakhstan), employing the Volume of Fluid (VOF) method for free-surface flow simulation and a non-Newtonian model for sediment transport and riverbed morphodynamics. To verify the developed mathematical model, experimental data on the flow in the L-shaped channel and Earthfill dam break were used, which provided high reliability of the calculated results. The calculations showed a significant increase in the channel area in the studied section of the Talas River (from 41,334.92 m² to 56,890.17 m²) for the period from 2019 to 2024, mainly due to the intensification of the dynamics of currents and the formation of additional vortex zones with a diameter of 50 to 200 m. It was found that in places of local flow acceleration, water velocity increased up to 4.5 m/s, leading to bank erosion and channel widening, whereas after redistribution of channel flows, the maximum velocity decreased to 2.8 m/s, ensuring stabilisation of morphological changes. The results of the study underline the need for an integrated approach to river morphodynamics management using numerical modelling to predict channel changes, minimise flood risks and optimise the use of water resources. The presented computational approach can be adapted to analyse hydrodynamic processes in other poorly studied river systems, which significantly expands its scientific and practical value. Full article

Climate change and aging infrastructure are undermining the resilience of urban flood management systems, reducing their reliability and increasing the likelihood of systemic failure that may culminate in regime shifts. This study develops a conceptual and practitioner-oriented screening framework based on a quantitative mathematical model to examine facility-level resilience and identify threshold conditions that may trigger regime transitions under external disturbances and varying pre-disturbance facility conditions. The framework adopts the composite sigmoid function (CSF) to capture nonlinear performance trajectories of infrastructure systems. Building on this model, this study extends its application by developing a parameterization scheme directly linked to four resilience dimensions: robustness, redundancy, rapidity, and resourcefulness (4Rs), which can be derived from field investigations or expert surveys. The normalized 4R scores are mapped to the CSF parameters, thereby converting static resilience assessment results into degradation and recovery curves. To search for threshold conditions, a parametric analysis was conducted by systematically varying the 4R values across their defined ranges. Rather than indicating a single universal threshold value, the results revealed critical threshold regions formed by specific combinations of the 4R dimensions. Lower robustness reduced the initial performance buffer, and low redundancy accelerated and extended performance degradation, while insufficient rapidity and resourcefulness delayed or limited recovery, increasing the likelihood of transition into an alternative degraded regime. For example, even when R1 and R2 were set to relatively high normalized values of 0.90, and R3 was set to its maximum value of 1.00, full recovery could not be achieved when R4 decreased below approximately 0.20. An illustrative application was conducted using preliminary 4R assessment results for flood-control facilities in three districts of Seoul, Korea. The model-derived trajectories were qualitatively compared with reported historical vulnerability patterns. While this comparison was intended as a contextual assessment rather than an event-specific empirical validation, our framework supports comparative, scenario-based screening of potentially vulnerable facilities for preliminary maintenance and investment prioritization. Full article

Pluvial flooding is intensifying in fast-growing coastal cities as rapid urbanization increases impervious surfaces and reduces natural infiltration, challenging planners to identify scalable and site-level mitigation strategies. Although statutory setbacks around institutional buildings are widely mandated for ventilation, safety, and accessibility, their contribution to urban flood resilience remains largely unexplored. This study develops the Flood Setback Performance Index (FSPI), a dimensionless indicator that integrates setback permeability and area-weighted runoff coefficients to quantify the flood-mitigation potential of mandatory setbacks. The framework was demonstrated using eight government school campuses in the Chennai, Chengalpattu, and Thiruvallur regions, which are part of a flood-prone coastal metropolis in India, following the extreme rainfall event of December 2025. Flood conditions were verified through post-event field surveys and visual evidence, while setback characteristics were extracted from satellite imagery and classified into permeable and impervious surfaces. The permeable fraction of setbacks and the FSPI values exhibited a strong inverse relationship with flood severity (Spearman’s ρ = −0.87, exact permutation p = 0.011). Ordinal logistic regression confirmed this gradient (likelihood-ratio χ² = 9.3–10.3, p ≤ 0.002, McFadden’s R² = 0.54–0.60), and campus rankings were made under saturated runoff coefficients. The findings demonstrate that statutory setbacks can function as nature-based flood-mitigation infrastructure with measurable hydrological benefits. Beyond the case study, the FSPI provides a simple, transferable, evidence-based tool for screening institutional sites by flood-mitigation performance and prioritizing where adaptation measures, such as increasing permeable-surface cover within statutory setbacks are needed, supporting climate-resilient urban planning and providing a regulatory reform decision-support tool with three applications: prioritizing the campus-level retrofit of permeable surfaces; screening building applications against setback surface standards; and identifying shelter-designated schools that require drainage upgrades. It thereby supports climate-resilient urban planning, regulatory reform, and progress toward Sustainable Development Goals 11 and 13. Full article

Background/Objectives: Melioidosis is an environmentally acquired infection caused by Burkholderia pseudomallei (B. pseudomallei). Although historically framed as a tropical disease, evidence indicates that recognized risk can extend beyond classical endemic regions. This narrative review synthesized Digital Object Identifier (DOI)-verified evidence on environmental persistence, climate-sensitive risk, geographic emergence, and One Health preparedness. Methods: Structured narrative searches of PubMed/Medical Literature Analysis and Retrieval System Online (MEDLINE), Europe PubMed Central (Europe PMC), Crossref, and publisher records were conducted for literature available up to 19 June 2026. Forty-four DOI-verified sources were retained. Evidence categories were derived inductively by inferential function during thematic synthesis and used as a qualitative interpretive framework, not as a validated quantitative risk score. Results: B. pseudomallei persists in soil and water, survives nutrient limitation, and clusters in environmental microfoci, but the interpretive value of detection depends on viability, exposure context, and diagnostic endpoint. Rainfall, humidity, flooding, and cyclones are associated with incidence, severity, or mobilization in several settings, supporting climate-sensitive risk rather than uniform geographic spread. Case-based evidence is strongest when it separates importation, local acquisition, environmental establishment, source attribution, and animal sentinel signals. Human risk depends on exposure route, host susceptibility, diagnostic recognition, and access to prolonged antimicrobial management, whereas animal evidence is best interpreted as sentinel or common-exposure evidence unless reservoir or direct-transmission data are available. Conclusions: Melioidosis beyond the tropics requires graded evidence interpretation because environmental detection, modeled suitability, animal signals, and human cases support different levels of geographic and One Health inference; this approach links early signals to surveillance while reserving higher-confidence claims for convergent evidence. Full article

Water security is a prerequisite for achieving the Sustainable Development Goals, yet water insecurity remains a critical challenge in urban slums. This study assesses the water security in the slums of Dhaka City, Bangladesh by integrating multiple dimensions of water security, such as water supply, sanitation and hygiene, water environment, water and climatic risks, and water governance. Suitable indicators and variables are used to capture the key dimensions of water security. A mixed-method approach, incorporating quantitative water quality assessment, waterlogging assessment and household survey, and qualitative focus group discussions, in-depth interviews and key informant interviews, is followed for data collection. The results reveal that the water security index (WSI), on a scale of 5.00, varies from 1.72 for Rajur slum to 3.34 for Nabinagar Housing slum. Among the dimensions, the score varies from 1.86 for water environment to 3.05 for water supply. Thus, there is a wide variation in WSI from slum to slum and in score from dimension to dimension. The study suggests improving drainage, sewerage and household solid waste collection systems, cleaning water bodies, improving drinking water quality, and raising awareness on menstrual hygiene management for enhancing water security in Dhaka’s slums. Full article

Phosphogypsum (PG), a gypsum-rich by-product of wet-process phosphoric acid production, is increasingly considered for land application because it can supply calcium and sulfur and alleviate constraints such as sodicity, subsoil acidity, and vegetation establishment limitations. However, PG may also contain residual acidity, soluble salts, fluoride, heavy metals, and naturally occurring radionuclides, creating multiple exposure pathways. This critical review distinguishes direct PG evidence from gypsum or sulfate analogue evidence, life cycle assessment/material flow analysis evidence, and risk control studies. It evaluates PG land application according to receiving soil conditions, diagnosed constraints, exposure pathways, and environmental safety boundaries. The strongest evidence supports use in diagnosed sodic and saline–sodic soils, whereas applications in Al-toxic acid subsoils, flooded paddy systems, contaminated or degraded soils, and non-food vegetated systems require conditional assessment. PG should therefore be treated as a context-specific management option rather than an unrestricted disposal route. By linking waste valorization with soil demand, source quality, exposure control, and long-term monitoring, the proposed framework contributes to sustainability by integrating circular resource use with soil health, water protection, food/feed safety, and risk-informed governance, while helping to prevent the transfer of environmental burdens across ecosystems or generations. Full article