Search Results (321)

Polymer gel profile control technology can effectively modify water flow channels in water-flooded oil reservoirs and enhance oil recovery. However, most polymer gel systems exhibit poor performance, such as low strength, not suitable for high-temperature and high-salinity reservoir conditions, leading to ineffective water shutoff. To address this challenge in complex formations of high-temperature, high-salinity fractured reservoirs, a temperature- and salt-tolerant polymer gel system with delayed crosslinking was developed based on the concept of slow hydrogen-bond crosslinking. Laboratory evaluations demonstrated that a gel system formulated with 0.4 wt% HPAM and 0.2 wt% PEI (HPAM/PEI) achieved a gel strength grade of G index. Even at 100 °C or a salinity of 200,000 ppm, the HPAM/PEI system maintained a gel strength grade of F, indicating excellent temperature resistance and shear stability. The slow hydrogen-bond crosslinking mechanism endowed the system with delayed gelation characteristics. Sandpack and core flooding experiments confirmed that the HPAM/PEI system could form high-strength gels in situ with low polymer retention. After treatment, the permeability of the core was reduced by over 99%, and the effective blocking duration exceeded 12 months. This study provides a theoretical foundation for applying the HPAM/PEI gel system in deep profile control and water shutoff in high-temperature and high-salinity reservoirs. Full article

Plants adapt to abiotic stresses by a variety of physiological and molecular mechanisms, among which the root plays important roles via responding to underground and soilborne signals. Fructan is a polysaccharide involved in energy metabolism and stress adaptation. Orobanche cumana is a holo-parasitic plant that mainly attaches to the root of the host sunflower (Helianthus annuus). Oc6-FEH, a fructan 6-exohydrolase from O. cumana, is involved in both fructan metabolism and flooding responses. Expression of Oc6-FEH is induced by flooding and indole-3-acetic acid (IAA). Oc6-FEH possesses fructan catabolism activity and is associated with fructose release. Overexpression of Oc6-FEH in the host sunflower reduces malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) accumulation, boosts the activities of antioxidant enzymes, including peroxidase (POD) and superoxide dismutase (SOD), and enhances photosynthetic performance. The expression level of Oc6-FEH was found to be positively associated with the flooding tolerance of invading O. cumana, which is connected to the host root. Furthermore, IAA treatment also improved the flooding tolerance of O. cumana. In summary, the metabolism of fructan and the activity of Oc6-FEH were demonstrated to ameliorate waterlogging stress. Oc6-FEH provides a promising genetic target for the improvement of flooding tolerance in crops. Full article

Floodplain forests in central Amazonia are structured along a marked flooding gradient that influences species distribution, performance, and survival. This study evaluated the demographic structure, survival, and growth responses of two co-occurring tree species across contrasting várzea environments differing in inundation regimes. Field surveys quantified seedlings, juveniles, and adults in low- and high-floodplain forests, while a field experiment assessed survival and growth under conditions with and without interspecific interaction. Repeated-measures ANOVA revealed that temporal variation and forest type significantly affected growth parameters, with species-specific responses to flooding intensity. In the field experiment, mortality of Crateva tapia L. differed significantly among treatments (χ² = 24.96, p < 0.001), with the highest mortality observed in high-várzea (up to 75% under interspecific interaction), while Hura crepitans L. showed 100% survival across all treatments. Non-parametric analyses detected no significant treatment effects on selected morphological traits. The results support the stress-gradient hypothesis, suggesting that plant–plant interactions may shift along the flooding gradient, with facilitative processes becoming more relevant under higher stress conditions. Overall, differential flood tolerance appears to be a key driver of habitat preference and population structure in these Amazonian wetlands. Full article

The impacts of climate change on Mediterranean weed flora were investigated to inform future weed management strategies. Projections indicate that rising temperatures and increased atmospheric CO₂ concentrations are likely to favor ruderal species characterized by rapid phenological development and high dispersal capacity. Enhanced abiotic stressors—such as elevated temperatures, water scarcity, and increased UV-B radiation—are expected to affect crops more severely than weeds, given the latter’s greater evolutionary potential to develop stress-tolerant biotypes. Moreover, the increased frequency and intensity of extreme events (e.g., drought, flooding, and soil salinization) may reduce weed community diversity, potentially leading to dominance by a limited number of highly competitive species and consequently intensifying reliance on chemical weed control. Simplification of weed communities may also increase vulnerability to the introduction and establishment of alien species, particularly those originating from hot and arid regions, some of which may be parasitic, toxic, or allergenic. Climate change-induced phenological mismatches between flowering plants and pollinators are likely to favor wind-pollinated weed species, further compromising the aesthetic and ecological quality of agricultural landscapes. Additionally, increased production of wind-dispersed allergenic pollen, together with the anticipated rise in herbicide applications, may pose significant risks to human health. An effective agronomic strategy to address future weed scenarios should include the genetic improvement in crops to enhance adaptive plasticity, exploiting germplasm from ancestral lines and related wild species. Full article

Flooding, as a major abiotic stress, significantly impacts the growth and survival of poplar plantations in the floodplains of the middle and lower reaches of the Yangtze River. Elucidating the molecular mechanisms underlying flooding responses in poplar is crucial for enhancing plantation productivity. In this study, two important eastern cottonwood cultivars, Populus deltoides ‘Jianghan 1’ (HBI) and P. deltoides Bartr. CL (CL), were investigated. By integrating long-term growth surveys and transcriptome sequencing, we analyzed their phenotypic traits and molecular responses to flooding stress. After 7 years of seasonal flooding, HBI exhibited a survival rate of 73.91%, along with superior height (23.1 m) and diameter at breast height (DBH, 26.3 cm), compared with CL, indicating HBI as a flooding-tolerant cultivar. Transcriptome analysis identified 1098 shared differentially expressed genes (DEGs) in the leaves of flooded HBI and CL, which were mainly enriched in stress signal perception, oxidative stress regulation, energy metabolism and circadian rhythm. Cultivar-specific DEG analysis revealed that CL mainly activated pathways related to oxidative stress and damage repair pathways, whereas HBI-specific genes were significantly enriched in hormone signal transduction, growth regulation, flavonoid synthesis and photosynthesis. Based on this distinct enrichment pattern in the tolerant cultivar HBI, we propose that it possesses adaptive advantages under flooding stress. Specifically, HBI likely coordinates multiple physiological processes by activating ethylene and other hormone-related genes, thereby regulating hypoxia adaptation, reoxygenation-induced oxidative stress, photosynthetic recovery, and flavonoid-mediated antioxidant defense. This coordinated regulation collectively sustains growth vigor and enhances survival under seasonal inundation. Our findings demonstrate clear transcriptomic divergence underlying flooding tolerance among poplar cultivars, laying a theoretical foundation for the selection of flooding-tolerant varieties and the sustainable development of forestry in flood-prone regions. Furthermore, these results broaden the current knowledge of flooding stress biology in woody plants. Full article

Rain gardens are increasingly implemented as Nature-Based Solutions for stormwater management, where vegetation must tolerate alternating wet and dry conditions driven by design-related drainage times. Despite the central role of plants, experimentally based guidance on species selection, particularly for locally adapted herbaceous taxa, remains limited. This study presents a controlled experimental screening of 13 native Italian herbaceous species to evaluate their response to two different submersion regimes. Plants were subjected to repeated short (1-day) and longer (3-day) submersion cycles and compared with a non-flooded control. Species performance was assessed through an integrated framework combining survival, growth responses, biomass allocation and visual condition. All species survived across treatments, indicating a general tolerance to transient waterlogging. However, interspecific differences emerged when multiple response variables were jointly considered. Several species not typically associated with prolonged inundation maintained high performance under longer submersion regimes, while some taxa from drier environments also showed resilience to waterlogging. The results highlight that tolerance to submersion cannot be inferred solely from habitat moisture affinity and that submersion duration represents a key design variable for rain garden design. This study provides a pragmatic, low-cost screening approach to support context-specific plant selection in temperate urban environments. Full article

Anaerobic germination tolerance (AGT) is a critical adaptive trait for rice establishment in flood-prone environments and direct-seeded systems. Here, we identified and validated the quantitative trait locus qAG2.1 for AGT and introgressed it into the elite lowland rice variety CR Dhan 801 through marker-assisted backcross breeding. The introgressed lines exhibited significantly improved germination under anaerobic conditions, demonstrating the effectiveness of qAG2.1 in a high-yielding genetic background. While CR Dhan 801 showed a low anaerobic germination percentage (17.6%), the donor ARC10424 exhibited 82.6%, and the best-performing introgressed line (22009-3) achieved 49.2%. Importantly, the improved lines maintained agronomic performance comparable to CR Dhan 801 under non-stress conditions, indicating minimal yield penalty. To gain mechanistic insight, the qAG2.1 interval was dissected in silico to prioritise candidate genes putatively associated with AGT. This analysis highlighted genes linked to ethylene biosynthesis and signalling (e.g., OsACO3, OsERF109), abscisic acid biosynthesis (OsNCED1), gibberellin homeostasis (OsGA2ox9), trehalose metabolism (OsTPS5, OsTPP1), detoxification of anaerobic by-products (OsALDH2A), and water transport (OsPIP1;3). Collectively, these results validate qAG2.1 as a further deployable locus for improving anaerobic germination in elite rice backgrounds and provide a set of putative candidate genes for future functional characterisation. Full article

As network attack methods continue to evolve, flooding attacks remain a major threat that causes network paralysis and service disruption. Statically configured systems are particularly vulnerable, as attackers can exploit reconnaissance information to launch large-scale attacks, while conventional defense mechanisms often fail under high-intensity traffic. To address this problem, this paper introduces Moving Target Defense (MTD) within a decentralized framework and proposes a blockchain-based decentralized End Hopping system. The system employs the Practical Byzantine Fault Tolerance (PBFT) consensus protocol for dynamic controller election and incorporates a disaster recovery mechanism, which eliminates single points of failure while ensuring reliable controller transitions and rapid service restoration. Experimental results demonstrate that the proposed system achieves satisfactory performance in terms of availability, effectiveness, and security, providing a practical approach to constructing robust proactive defense networks. Full article

The co-occurrence of microplastics (MPs) and cadmium (Cd) in agricultural soils poses ecological risks, yet their interactions in flooded rice paddies remain unclear. Therefore, this study investigated the individual and combined effects of polyethylene MPs (mPE) and Cd on rice (Oryza sativa L.) growth, Cd accumulation, and soil microbial communities. Combined stress (5 mg/kg Cd + 1% mPE) significantly reduced rice growth (4.1–13.8% in plant height) and increased Cd accumulation in roots, stems, and seeds, driven by MP-enhanced Cd bioavailability. MPs altered soil pH, organic matter (OM), and moisture content (MC), indirectly suppressing yield. Microbial analysis revealed decreased bacterial alpha diversity (0.86–8.36%), favoring Cd-tolerant taxa (e.g., Solirubrobacteraceae), while fungal responses were weaker under flooding. Structural equation modeling indicated that Cd exerted direct toxicity through tissue accumulation, whereas MPs acted indirectly by modifying soil properties and inducing oxidative stress. Under co-exposure, MPs intensified Cd-induced oxidative stress, enhancing both direct and indirect toxicity pathways. Mantel tests identified DTPA-extractable Cd (r = 0.70) and OM (r = 0.55) as key drivers of Cd uptake. These findings highlight the complex interplay of MPs and Cd in rice paddies, with implications for managing co-contaminated agroecosystems. Full article

Despite reductions in sulphur and nitrogen emissions, lakes and streams in Europe and North America have shown only partial recovery from acidification. This study aims to assess the chemical and biological recovery of the upper stretch of the Litavka River, currently on of the most acidic stream in the Czech Republic. Water composition and macroinvertebrates were studied for 1999, 2010, and 2021, along with long-term data on hydrology and climate. Over these 22 years, concentrations of SO₄²⁻, base cations, conductivity, and toxic Al forms (Al_i) significantly decreased, but pH only increased from 4.2 to 4.3. Biological recovery was most evident during 1999–2010, with an increase in the number of taxa and the appearance of less acid-tolerant taxa such as stonefly Diura bicaudata and caddisfly Rhyacophila sp., mainly associated with decreased Al_i toxicity. Subsequently, however, despite continued chemical improvement, macroinvertebrate diversity decreased, and sensitive taxa were again absent in 2021. Average annual temperature increased by 2.4 °C over the past 50 years (1970–2020) while precipitation remained unchanged, resulting in significant aridification of the regional climate. We attribute the lack of biological recovery in 2021 to climate-related changes, including more frequent dry periods and floods. Although partial biological recovery of the river followed chemical recovery, the increasing frequency of hydrological extremes has likely become the main limiting factor. Full article

This work presents an innovative concept of a mobile micro-water turbine for energy recovery from flood-threatened rivers, combining environmental protection with renewable energy production. In response to the increasing frequency and intensity of floods caused by climate change, the authors propose active utilisation of the kinetic energy of water masses during these events through the installation of mobile water turbines along rivers. Rather than merely mitigating the consequences of floods, the energy from flowing water can be converted into electrical current, and the water can be purified and used for other purposes. The article analyses various solutions for water turbines, including the Kaplan turbine, Banki–Michell turbine, and screw turbine, taking into account their efficiency and ability to adapt to changing flow conditions. For the Biała Lądecka river, it was demonstrated that a mobile micro turbine operating for three days can generate a significant amount of energy for on-site consumption or storage. The key challenge is the development of effective water filtration and treatment systems to remove pollutants brought by floods, as well as mobile platforms enabling rapid assembly and disassembly of turbines at threatened sites. The comparative analysis of turbines conducted makes it possible to determine the optimal choice for mobile systems due to operation at low heads, simple construction facilitating installation, and tolerance for contaminants. Full article

Agricultural production remains highly susceptible to water-related risks, such as drought and flooding. Although hydrologic forecasting systems, such as the National Water Model (NWM), have advanced considerably, their outputs are rarely used for real-time agricultural decision-making. This study developed the Agricultural Water Risk Indicator (AWRI), a framework that translates NWM streamflow forecasts into crop-specific risk assessment indicators. The AWRI framework has three key components: (1) the hydrological threat and exposure characterization based on NWM streamflow forecasts (B1); (2) crop sensitivity by growth stage and water needs (B2); and (3) adaptive capacity reflecting the presence of irrigation or drainage infrastructure (B3). The AWRI was evaluated across three NWM reach IDs covering five farm sites in the Black Belt region of Alabama, USA. The results show that the AWRI captured variations in hydrologic conditions, risk, and crop tolerance across the research sites within the one- to four-week forecast range. Crops in the reproductive stage were especially sensitive. Without resilience measures, up to 55% of the crops simulated at some sites had high-risk AWRI categories. Including irrigation or drainage decreased risk scores by one to two levels. The AWRI tool provides farmers and stakeholders with critical information to support proactive agricultural water management. Full article

A low-permeability, high salinity reservoir entered the high-water-cut and high recovery degree stage in the middle and late stages of development, and it is difficult to tap the potential of water flooding. The overall water flooding recovery of the developed low-permeability reservoir is low, and the produced water has high oil content, many granular impurities, and high inorganic salt content. The polymer–surfactant binary system was studied according to the reservoir conditions. The polymer acrylic acid/polyacrylamide/2-acryloylamino-2-methyl-1-propanesulfonic acid was selected by viscosity measurement. The viscosity stability of the polymer and the effect of the flooding system were evaluated, and the salt-tolerant surfactant sulfonated betaine + amides and coco composite system were screened, and the viscosity, interfacial tension, and displacement effect were evaluated. Finally, the polymer–surfactant binary flooding system was formed. The system has good compatibility, the interfacial tension can still be reduced to 10⁻³ mN/m at 40 °C and 23,800 mg/L, and the viscosity of the polymer solution increased by 5.8% upon addition of the surfactant. The composite system can improve the oil displacement efficiency by 21.19%. The results of a parallel core displacement experiment with a 3.91 permeability ratio show that the oil displacement efficiency can be improved by 19.96%. The system has good performance in low-permeability oilfields and can effectively displace crude oil, which is of great significance for the displacement of low-permeability heterogeneous reservoirs. Full article

To address the problem of serious gas channeling during CO₂ flooding in low-permeability reservoirs, which leads to poor oil recovery, this study developed a CO₂-resistant gel using a novel CO₂-responsive polymer (ADA) for gas channel control. The ADA polymer was synthesized via free-radical copolymerization of acrylamide (AM), dimethylaminopropyl methacrylamide (DMAPMA), and 2-acrylamido-2-methylpropanesulfonic acid (AMPS), which introduced protonatable tertiary-amine groups and sulfonate moieties into the polymer backbone. Comprehensive characterizations confirmed the designed structure and adequate thermal stability of the ADA polymer. Rheological tests demonstrated that the ADA polymer solution exhibits significant CO₂-triggered viscosity enhancement and excellent shear resistance. When crosslinked with phenolic resin, the resulting ADA gel showed outstanding CO₂ tolerance under simulated reservoir conditions (110 °C, 10 MPa). After 600 s of CO₂ exposure, the ADA gel retained over 99% of its initial viscosity, whereas a conventional HPAM-based industrial gel degraded to 61% of its original viscosity. The CO₂-resistance mechanism involves protonation of tertiary amines to form quaternary ammonium salts, which electrostatically interact with sulfonate groups, creating a reinforced dual-crosslinked network that effectively protects the gel from H⁺ ion attack. Core flooding experiments confirmed its ability to enhance oil recovery by plugging high-permeability channels and diverting flow, achieving a final recovery of up to 48.5% in heterogeneous cores. This work provides a novel gel system for improving sweep efficiency and storage security during CO₂ flooding in low-permeability reservoirs. Full article

Waterlogging is a major abiotic stress that restricts plant growth, productivity, and survival by disrupting root aeration and altering hormonal homeostasis. To elucidate the physiological and molecular responses associated with flooding tolerance in Liriodendron hybrids (Liriodendron chinense × Liriodendron tulipifera), this study investigated its morphological, physiological, and transcriptomic changes under 0, 1, 3, and 6 days of waterlogging. Roots exhibited rapid decay, while leaves showed delayed chlorosis and reduced chlorophyll content. Changes in antioxidant enzyme activities reflected enhanced antioxidant capacity, with superoxide dismutase (SOD) activity decreasing and peroxidase (POD) and catalase (CAT) activities increasing. Hormone measurements indicated organ-specific patterns, including abscisic acid (ABA) accumulation in leaves and decreased indole-3-acetic acid (IAA) and gibberellin (GA) levels in both roots and leaves. Transcriptome profiling revealed extensive transcriptional adjustments in hormone biosynthesis, signaling, and stress-responsive pathways, including divergent regulation of ABA-associated genes in leaves and roots and broad downregulation of auxin- and gibberellin-related genes. Key ABA biosynthetic genes (NCED1, ABA2) and signaling components (PYL4, PP2C, ABF) were upregulated in leaves but downregulated in roots, whereas auxin (YUC6) and gibberellin (GA20ox) genes were generally suppressed. These coordinated physiological and molecular responses suggest organ-differentiated adaptation to waterlogging in Liriodendron hybrids, highlighting candidate pathways and genes for further investigation and providing insights for improving flooding tolerance in woody species. Full article