Search Results (256)

This study presents a practical early-warning approach for heavy rainfall detection using the temporal dynamics of satellite-derived Cloud-Top Temperature (CTT). A rapid rise followed by a sharp fall in CTT is identified as a precursor signal of convective intensification. By quantifying the $rise-peak-fall-trough$ pattern and the $peak$-to-$trough$ amplitude ($swing$), a $\mathrm{W}\mathrm{A}\mathrm{T}\mathrm{C}\mathrm{H}$ window—representing a potential heavy-rainfall candidate period—is defined. The observed lead time between the onset of CTT decline and the subsequent radar-observed rainfall surge is calculated, while an estimated lead time is inferred from the steepness of CTT fall in the absence of a surge. Application to eight heavy rainfall events in Korea (July 2025) yielded a probability of detection (POD) of 87.5%, indicating that potential heavy rainfall could be detected approximately 1.3–8.6 h in advance. Compared with radar-based nowcasting, the CTT $\mathrm{W}\mathrm{A}\mathrm{T}\mathrm{C}\mathrm{H}$ method retained predictive skill up to 3 h before numerical model guidance became effective, suggesting that satellite-based signals can bridge the forecast gap in short-term prediction. This work demonstrates a clear methodological novelty by introducing a physical interpretable, pattern-based metric. Quantitatively, the $\mathrm{W}\mathrm{A}\mathrm{T}\mathrm{C}\mathrm{H}$ method improves early-warning capability by providing 1–3 h of additional lead time relative to radar nowcasting in rapidly evolving convective environments. Overall, this framework provides an interpretable, low-cost module suitable for operational early-warning systems and flood preparedness applications. Full article

Background: The 2022 Pakistan floods devastated healthcare access for pregnant women in already impoverished areas in Sindh province. This study examines how Cash for Health assistance (CH) of USD 112 alleviated financial burdens and improved maternal health outcomes and resilience, bridging a critical literature gap on cash effectiveness in humanitarian crises. Methodology: This study used a mixed-methods approach to assess the CH assistance intervention for families of pregnant/lactating women in flood-affected rural Sindh, Pakistan. A pre-post quantitative analysis of baseline (May–June 2024) and endline (August–November 2024) survey data in ~100 villages (Jamshoro/Sehwan) examined changes in healthcare access, expenditure, and preferences using t-tests, proportion tests, and multivariable regression. Concurrently, five qualitative case studies from key informant interviews provided thematic content analysis, triangulating findings on economic, health, and social impacts. Results: Respondents predominantly had low literacy rates and were from households of daily wage laborers in vulnerable, flood-affected areas. While income and education remained low, instances of forgone care due to financial barriers increased (68% to 97%, p < 0.001). CH significantly improved healthcare access (58% to 98%, p < 0.001). Access to regular physicians (20% to 69%) and private facilities (10% to 41%) notably expanded. Healthcare expenditure significantly increased from USD 9.3 to USD 25, with a shift in spending preference towards medication, consultations, and diagnostics. CH also significantly improved food security (21% to 97%), meal frequency, and overall household stability, including reducing domestic violence. Qualitative data emphasized pre-existing vulnerabilities and CH’s role in addressing health, nutrition, and psychosocial needs. Conclusions: CH significantly improved healthcare access and reduced financial burdens for vulnerable pregnant women post-disaster. However, a sustainable impact requires integrated “cash plus” models, combining financial aid with stronger health systems, psychosocial support, and literacy for long-term resilience. Full article

The relationship between Nile flood variability and Egyptian political stability has been studied since Barbara Bell’s pioneering work in the 1970s, yet precise causal mechanisms linking environmental stress to societal crisis have remained elusive due to chronological limitations. This paper presents a methodological framework achieving annual to decadal resolution through volcanic forcing of the East African Monsoon. Large volcanic eruptions disrupt atmospheric circulation, suppressing monsoon rainfall over the Ethiopian Highlands and reducing Nile summer floods with impacts precisely dated through ice core chronologies (±1–2 years). Applied to Ptolemaic Egypt (305–30 BCE), this methodology demonstrates that volcanic-induced flood failures significantly increased revolt probability (p < 0.02) and correlated with land sales, warfare cessations, and economic stress indicators. Statistical validation distinguishes causal relationships from chance correlations, while comparative analysis of early versus late Ptolemaic responses reveals how political legitimacy, fiscal capacity, and institutional strength determined societal resilience versus vulnerability to environmental shocks. This approach achieves temporal resolution beyond the century-scale resolution of previous studies, determining temporal sequence essential for establishing causation. The methodology is replicable across historical contexts where documentary sources overlap with ice core volcanic chronologies, offering a template for integrating paleoclimatic precision with historical analysis to understand human–environment interactions in past societies. Full article

Prolonged water injection in conventional heavy oil reservoirs typically leads to high water cut and a substantial reduction in recovery rate. This study explores the synergistic effects of a composite flooding process, where associated gas-assisted surfactant-polymer (SP) flooding is enabled by prior gel conformance control, to enhance oil recovery in these reservoirs. Through high-temperature, high-pressure microscopic visualization experiments and heterogeneous core flooding tests, the oil displacement mechanisms and enhanced recovery effects of this composite system were systematically investigated. The results show that SP flooding, through viscosity enhancement and reduction in interfacial tension, achieves the highest microscopic oil displacement efficiency, with an oil recovery of 81% and a significant reduction in clustered residual oil to just 9%. Associated gas flooding improves oil mobility by reducing viscosity and promoting expansion through gas dissolution, resulting in a recovery efficiency of 62%, which outperforms traditional viscosity reducers (58%). Heterogeneous core flooding experiments demonstrate that a composite strategy involving gel plugging, associated gas assistance, and SP flooding increases recovery by 24% compared to water flooding. The system also exhibits excellent flow control and maintains a low water cut, confirming the promising potential of this gel-conformance-controlled, associated gas-assisted SP flooding strategy as an effective method for enhancing recovery in high-water-cut heavy oil reservoirs. Full article

Background and clinical significance. Penetrating cardiothoracic wounds require prompt treatment in order to decrease mortality and morbidity. Surgical therapy, aimed at bleeding control and removal of damaged tissue, varies widely from the direct suture of parenchymal lacerations to pneumonectomy, which is characterized by high mortality rates. We report our experience with a patient in hemorrhagic shock due to a gunshot wound to the chest, successfully treated by pneumorrhaphy under cardiopulmonary bypass (CPB). Case presentation. A 53-year-old man with a gunshot wound to the chest was admitted to our Emergency Department. A bedside ultrasonography revealed left pleural and pericardial effusion. He was hemodynamically instable, so he was immediately transferred to the operating room by the cardiac and Thoracic Surgery teams. Through a median sternotomy approximately 2 L of blood were evacuated and a deep laceration of the left upper lobe was discovered. The massive bleeding could not be controlled, leading to pleural cavity flooding. The surgical team decided to institute emergency CPB and perform lung repair by pneumorrhaphy, under circulatory support. The patient survived and was discharged on p.o. day 20. Conclusions. Clinical expertise, adequate instrumental equipment and a high level of interdisciplinary team-work favorably affected the patient’s outcome. Full article

Accelerating urbanization and the intensifying pace of climate change have heightened the occurrence of urban pluvial flooding, threatening urban sustainability. As the preferred approach to urban stormwater management, coupled gray and green infrastructure (GI–GREI) integrates GREI’s rapid runoff conveyance with GI’s infiltration and storage capacities, and their siting and scale can affect life-cycle cost (LCC) and urban drainage system (UDS) resilience. Focusing on Fengxi New City, China, this study develops a multi-objective optimization framework for the GI–GREI system that integrates GI suitability and pipe-network importance assessments and evaluates the Pareto set through entropy-weighted TOPSIS. Across multiple rainfall return periods, the study explores optimal trade-offs between UDS resilience and LCC. Compared with the scenario where all suitable areas are implemented with GI (maximum), the TOPSIS-optimal schemes reduce total life-cycle cost (LCC) by CNY 3.762–4.298 billion (53.36% on average), rebalance cost shares between GI (42.8–47.2%) and GREI (52.8–57.2%), and enhance UDS resilience during periods of higher rainfall return (P = 20 and 50). This study provides an integrated optimization framework and practical guidance for designing cost-effective and resilient GI–GREI systems, supporting infrastructure investment decisions and climate-adaptive urban development. Full article

Continental high water-cut reservoirs commonly exhibit strong heterogeneity, high viscosity, and insufficient reservoir drive, which has motivated the deployment of polymer-based composite chemical flooding, such as surfactant–polymer (SP) and alkali–surfactant–polymer (ASP) processes. However, conventional experimental techniques have limited ability to resolve intermolecular forces, and the coupled mechanism linking “formulation composition” to “microstructural evolution” remains insufficiently defined, constraining improvements in field performance. Here, scanning electron microscopy (SEM), backscattered electron (BSE) imaging, and molecular dynamics (MD) simulations are integrated to systematically investigate microstructural features of polymer composite systems and the governing mechanisms, including hydrogen bonding and electrostatic interactions. The results show that increasing the concentration of partially hydrolyzed polyacrylamide (HPAM) promotes hydrogen bond formation and the development of network structures; a moderate amount of surfactant strengthens interactions with polymer chains, whereas overdosing loosens the structure via electrostatic repulsion; the introduction of alkali reduces polymer connectivity, shifting the system toward an ion-dominated dispersed morphology. These insights provide a mechanistic basis for elucidating the behavior of polymer composite formulations, support enhanced chemical flooding performance, and ultimately advance the economic and efficient development of oil and gas resources. Full article

As climate change and urbanization accelerate, urban flooding poses an increasingly severe threat to urban residents and their properties, creating an urgent need for effective solutions to achieve sustainable urban disaster management. While physically based hydrodynamic models can accurately simulate urban floods, they are data- and computational-resource-demanding. Meanwhile, artificial intelligence models driven by data often lack generalizability across different urban areas. To address these challenges, integrating spiking neural networks, graph convolutional networks (GCNs), and particle swarm optimization (PSO), a novel PSO-enhanced spiking graph convolutional neural network (P-SGCN) is proposed. The model is trained on a self-constructed dataset based on social media data, incorporating six representative Chinese cities: Beijing, Shanghai, Shenzhen, Wuhan, Hangzhou, and Shijiazhuang. These cities were selected for their diverse urban and flood characteristics to enhance model generalizability. The P-SGCN significantly outperforms baseline models such as GCN and long short-term memory, achieving an accuracy, precision, recall, and F1 score of 0.846, 0.847, 0.846, and 0.846, respectively. These results indicate our model’s capability to effectively handle data from six cities while maintaining high accuracy. Meanwhile, the model improves single-city performance through transfer learning and offers extremely fast inference with minimal energy consumption, making it suitable for real-time applications. This study provides a scalable and generalizable solution for urban flood risk management, with potential applications in disaster preparedness and urban planning across varied geographic and socioeconomic contexts. Full article

Waterlogging is an increasing constraint to crop productivity under climate change, yet information on quinoa’s sensitivity to excess water remains limited. This study aimed to identify the most vulnerable phenological stage of quinoa to waterlogging stress. A greenhouse experiment was conducted using the variety Tunkahuan, applying waterlogging (12 days) at six growth stages according to the BBCH scale, plus a well-drained control. Growth, chlorophyll content, biomass, yield components, and harvest index were assessed. Waterlogging significantly reduced growth and yield at all stages (p ≤ 0.05). Early vegetative stress reduced canopy cover and chlorophyll, with partial recovery after stress removal, but caused 73% plant mortality at BBCH 25. Reproductive stress, especially at anthesis (BBCH 60–67), was most critical, reducing yield by 71–77% compared to the control due to severe declines in grain number and harvest index. Stress during grain filling caused moderate yield reductions (22–28 g plant⁻¹). We conclude that quinoa is sensitive to waterlogging throughout its development, but anthesis is the most vulnerable stage for irreversible yield loss. These findings highlight the need for breeding programs targeting waterlogging tolerance and improved management practices to minimize flooding risk during flowering. Full article

Aligned with Saudi Arabia’s Vision 2030 and its corresponding global direction, this study aimed to identify and evaluate an environmentally friendly and alternative material to replace conventional synthetic polymers for polymer flooding. Extracting biopolymer solution, characterizing rheological properties, and conducting core-flooding experiments (seawater flood (SWF), secondary polymer flood (PF), and tertiary polymer flood) were experimentally investigated under simulated reservoir conditions (75 °C, 165,000 ppm TDS brine, and 2000 psi pore pressure). Biopolymer solutions were successfully generated from powdered pomegranate peels, and rheological characterizations of solutions with different shear rates, temperatures, and pomegranate-peel concentrations were investigated. Results revealed that significant shear-thinning behavior was pronounced in the biopolymer solutions, where 7% solution was selected for core-flooding tests. 7% solution exhibited 14.4 cP apparent viscosity at 13.2 s⁻¹ shear rate and 75 °C, indicating good thermal stability. Interfacial tension (IFT) results demonstrated high IFTs compared to the required IFT to reduce capillary forces, indicating that improved mobility control through viscosity enhancement serves as dominant EOR mechanism. The results indicated that PF yielded a higher ultimate oil recovery (62.2%) compared to SWF (47.6%) and tertiary polymer flood (58.0%). Results demonstrated that significant pressure fluctuations during polymer injection were observed, highlighting injectivity challenges. From all results, pomegranate peels would be potentially used to generate a biopolymer solution and replace environmentally hazardous materials. Full article

This paper proposes the lower-bounded Fréchet–log-logistic distribution (LFLD), a probability model designed for robust flood frequency analysis (FFA). The LFLD addresses key limitations of traditional distributions (e.g., generalized extreme value (GEV) and log-Pearson Type III (LP3)) by combining bounded support ($\alpha <x<\infty$) to reflect physical flood thresholds, flexible tail behavior via Fréchet–log-logistic fusion for extreme-value accuracy, and maximum entropy characterization, ensuring optimal parameter estimation. Thus, we obtain the LFLD’s main statistical properties (PDF, CDF, and hazard rate), prove its asymptotic convergence to Fréchet distributions, and validate its superiority through simulation studies showing MLE consistency (bias < 0.02 and mean squared error < 0.0004 for $\alpha$) and empirical flood data tests (52- and 98-year AMS series), where the LFLD outperforms 10 competitors (AIC reductions of 15–40%; Vuong test p < 0.01). The LFLD’s closed-form quantile function enables efficient return period estimation, critical for infrastructure planning. Results demonstrate its applicability to heavy-tailed, bounded hydrological data, offering a 20–30% improvement in flood magnitude prediction over LP3/GEV models. Full article

Biochar application can effectively immobilize Cadmium (Cd) in soil. However, it is largely unknown how the biogeochemical processes of sulfur (S) in biochar affect Cd fixation under conditions of decreasing pe + pH. Using two field-contaminated paddy soils with different Cd concentrations (Shangyu (SY) 0.56 mg kg⁻¹ and Tongling (TL) 2.32 mg kg⁻¹), and rape straw biochars with low S (LB) and high S (HB) contents, we investigated how S-rich biochar regulates Cd solubility in paddy soils that were incubated anaerobically for 40 d. The soluble and extractable Cd content decreased as pe + pH decreased with flooding, and showed a steady trend by day 20. However, Cd was immobilized through different mechanisms in TL and SY soil. The rapid decrease in pe + pH in TL soil enhanced the involvement of S in Cd immobilization and Fe transformation. In SY soil, the delayed reduction in SO₄²⁻ promoted Cd adsorption onto amorphous Fe oxides. During this process, the liming effect of biochar is critical for Cd immobilization in soil. Furthermore, biochar might promote the biogeochemical processes of S and Fe transformation, thereby enhancing Cd fixation in soils. Full article

Flooding from hurricanes creates damp indoor environments that support mold growth and microbial contamination, posing long-term health risks for occupants. This pilot study evaluated TMVOCs, microbial activity, and environmental conditions in 13 Hurricane Ian-affected residences across multiple flood-affected neighborhoods. Air samples were collected using sorbent tubes and analyzed by gas chromatography–mass spectrometry, while microbial activity on surfaces was assessed via ATP bioluminescence. Visible mold and dampness were documented with the CDC/NIOSH Dampness and Mold Assessment Tool, and environmental measurements included temperature, relative humidity, and surface as well as hidden moisture. Median (IQR) TMVOC concentrations were 12 (8) µg/m³, with 61% of homes exceeding the 10 µg/m³ benchmark set by previous researchers despite minimal visible contamination. Spearman’s correlation revealed significant negative relationships between odor and surface microbial activity (ρ = −0.569, p < 0.05), indicating that organic debris may play a more crucial role in microbial activity within the tested homes, and that odors might originate from hidden microbes instead of surface microbial growth. Our study emphasizes the necessity of utilizing both chemical (TMVOC) and biological (ATP) indicators to evaluate poor air quality caused by molds in flood-affected homes, serving as a supplement to routine visible mold assessments. Full article

Rice is one of the world’s most consumed foods, and the cereal that most efficiently uptakes and accumulates As, contributing to human health risk. Flooded rice fields alter Eh-pH conditions and, consequently, the proportion of As(III)/As(V), favoring their accumulation in the crop. The use of algae in paddy soils can improve fertility and C-stock and affect chemical conditions and As availability. This study aimed to evaluate the effect of algae application on: As adsorption capacity in paddy soils from Sado, Portugal, changes in pH-Eh conditions in the soil–water environment, and consequent As speciation. Batch-based As adsorption assays were performed with different solid–solution ratios and Chlorella minutissima algae application, and fitted to the Freundlich and Langmuir linear models. In semi-continuous column assays, simulating rice field conditions, the effect of algae on the pH-Eh of soil pore water was evaluated. The soil quality assessment showed pseudo-total contents of As and other elements higher than Portuguese agriculture limits (11 mg As kg⁻¹), but their availability was low, posing no environmental risk. The studied soils had great As adsorption, which increased with algae application (1.07 mg g⁻¹). Algae application favored oxygenation, increasing Eh values, and maintaining As(V) species. This indicated a potential approach to reducing As(III) mobility. Full article

The Yangtze River Basin is vital to China’s water security and flood management yet lacks a basin-wide quantitative assessment of long-term hydroclimatic changes. This study uses the high-resolution CMFD 2.0 dataset and the VIC model to evaluate spatiotemporal trends in precipitation and natural streamflow from 1951 to 2020. The results show a significant increase in annual precipitation in the upper basin (1.10 mm yr⁻¹, p < 0.05), particularly during the wet season, with spatially concentrated increases along the eastern Tibetan Plateau. The VIC model performed reliably across major stations, with NSE > 0.9 and PBIAS within ±10% during calibration. Natural streamflow trends are spatially heterogeneous: upper mainstream stations (e.g., Shigu, Panzhihua, Zhutuo) exhibit significant increases (6.25–14.58 m³/s per year), while lower stations remain stable or decline. Seasonally, wet-season streamflow increased in the upper basin, whereas dry-season streamflow decreased in the middle and lower reaches. At Yichang, natural simulations reveal growing seasonal extremes, with rising wet-season and declining dry-season flows (−19.06 m³/s yr⁻¹). Human interventions have partially offset these extremes. Since 1990, observed peak discharge at Yichang during the wet season has decreased by 10.04% compared to natural streamflow, while the dry-season minimum discharge has increased by 27.63%. This shows that large reservoirs help reduce flood peaks and increase low flows. These findings highlight the intensifying impacts of climate variability and human regulation on hydrological processes and provide a scientific basis for adaptive water resource management in large river basins. Full article