Search Results (11,383)

This study was based on a target spectrum (GB183062015) and synthesized different characteristic periods, pulse ground motions, and non-pulse ground motions utilizing EQsignal v1.2.1 software. It also investigated the dynamic behaviors of bridge piers in seismic motions with varying characteristic periods, pulse and non-pulse effects, and the influence of 0 m and 10 m water depths. The findings indicated that the peak acceleration and stress behaviors vary significantly under different characteristic periods of ground motion. The maximum error in peak acceleration behavior of a bridge pier under ground motions of varying characteristic periods is 19.25%, while the maximum error in peak stress response is 11.35%. The acceleration and stress behaviors of a bridge pier under pulse ground motion action are more considerable than those under non-pulse seismic motion action. When the characteristic period is 0.40 s, the maximum error in peak acceleration of the bridge pier structure under pulse seismic motion and non-pulse seismic motion action is 86.08%, with the maximum error of the peak stress reaches 80.68%. The existence of water serves to minimize the natural frequency of the bridge pier. The pulse effects result in a maximum error of 40.49% for the peak acceleration and a maximum discrepancy of 323.08% for the peak stress of the bridge pier. The hydrodynamic effects result in a maximum error of 33.51% for the acceleration peak and 12.90% for the stress peak of the bridge pier. The effect of the pulse symptoms on the dynamic behavior of the bridge pier is considerably more pronounced than that of the hydrodynamic effects, with an intricate and complex influencing mechanism. In bridge flood protection and seismic design and optimization, it is essential to consider the impact of pulse seismic motion with varying characteristic periods. Full article

Climate change and geological shifts were pivotal in the survival and development of ancient human societies, especially in densely populated regions like the middle and lower Lishui River Basin. This study explored the dynamic interactions between ancient human cultures and the region’s natural environment, using field research alongside geological, geomorphological, and archaeological data spanning from the late Paleolithic to the Neolithic periods. Our findings showed that prehistoric sites in the middle and lower Lishui River Basin were primarily located in the low hilly areas surrounding the lower basin during the Paleolithic era, a pattern shaped by the region’s geomorphology. Early human settlements were strategically positioned near the Lishui River, offering access to vital resources while minimizing flood risk. These locations provided flat terrain, abundant vegetation, and materials for tool-making, factors that supported a hunting and gathering lifestyle. As the coldest phase of the last glacial period approached, the transition from the Paleolithic to the Neolithic eras marked a period of significant behavioral adaptation. In response to the harsher environment, humans began settling on lower terraces and miniaturizing their stone tools, signaling a shift to more specialized hunting techniques. This adaptability and resilience marked the refinement of hunting economies during this period. With the onset of the Holocene epoch and a warmer climate, conditions for human habitation became more favorable. Societies began migrating from the hills to the fertile lower Lishui River Basin, heralding the Neolithic period. This era saw the emergence of settlements and the onset of early rice cultivation, marking the transition from a hunting–gathering economy to one centered on agriculture. By the Daxi period, these settlements had expanded, extending their influence throughout the region. In conclusion, this study underscores the critical roles of climate change and geological features in shaping human settlement patterns, economic activities, and cultural evolution in the middle and lower Lishui River Basin. Our findings offer valuable insights into the evolutionary processes of ancient human cultures in the region and provide a foundation to understand future challenges in sustainable development. Full article

Most river deltas worldwide are located in well-developed, densely populated lowland regions that face challenges from accelerated sea level rise. Deltas with morphological equilibrium are the foundation for associated prosperous economies and societies, as well as for preserving ecological fragile environments. And for deltas to be in morphological equilibrium, sufficient fluvial sediment supplies are fundamental. Severe droughts have significant impacts on the sediment load discharged to the sea, but this is considerably less studied compared to flooding events. This study examines the characteristics of Yangtze River sediment flowing toward the East China Sea during severe droughts. The effect of the Three Gorges Dam (TGD) was investigated by comparing the difference before and after its construction in 2003. Results indicate that the sediment load from the Yangtze River to the sea has experienced a more pronounced decrease during severe drought years since 2003. The primary cause is a substantial reduction in sediment supply from the upper reaches, resulting from the impoundment of the Three Gorges Reservoir created in 2003 and the construction of additional major reservoirs in the upper reach thereafter. Simultaneously, this is accompanied by the fining of sediment grain size. The fining of sediment and considerably reduced sediment load discharged to the sea during severe droughts after 2003 are likely to accelerate the erosion of the Yangtze subaqueous delta. The rating parameter values during severe drought years fall within the range observed in normal years, indicating that these drought events do not align with extreme rating parameter values. Less than 30% of the average discrepancy between measured and reconstructed sediment loads in severe drought years before 2003, and approximately 10% of the discrepancy after 2003, demonstrate the feasibility of reconstructing sediment loads for severe drought events using a sediment rating curve. This rating curve is based on daily water discharge and sediment concentration data collected during the corresponding period. These findings indicate that the rating curve-based reconstruction of sediment load performs well during severe droughts, with relative error slightly exceeding the average error of normal years prior to 2003 and approaching that observed after 2003. This study provides insights on sediment management of the Yangtze River system, including its coastal zone, and is valuable for many other large river systems worldwide. Full article

As urban centers worldwide face the escalating impacts of climate change, rapid urbanization, and increasing water scarcity, the need for sustainable water management practices to enhance urban resilience in the Anthropocene has become critical. This study explores how ancient water management practices—including Roman aqueducts, Maya rainwater harvesting systems, and ancient Chinese flood control techniques—can be adapted to address contemporary water challenges in modern cities. We evaluate these historical practices through a lens of contemporary environmental pressures, including climate change, urbanization, and resource scarcity. By integrating ancient methods with modern technologies, we propose adaptive solutions to enhance urban water resilience. Case studies from five cities (Singapore, Copenhagen, Mexico City, Los Angeles, and Philadelphia) illustrate how modern green infrastructure, inspired by ancient techniques, is being successfully implemented to manage stormwater, mitigate urban flooding, and improve water conservation. By integrating historical practices with modern technologies—such as advanced filtration systems and water recycling—these cities are enhancing their water resilience and sustainability. The findings suggest that urban planners can draw valuable lessons from historical systems to design adaptive, climate-resilient cities that balance human needs with ecological sustainability. This paper concludes with actionable recommendations for future urban planning, emphasizing the importance of decentralized water systems, nature-based solutions, and community engagement to ensure sustainable urban water management in the Anthropocene. Full article

Understanding the intricate relationship between drought stress and corn yield is crucial for ensuring food security and sustainable agriculture in the face of climate change. This study investigates the subtle effects of drought stress on corn physiological, morphological, and spectral characteristics at different growth stages, in order to construct a new drought index to characterize drought characteristics, so as to provide valuable insights for maize recovery mechanism and yield prediction. Specific conclusions are as follows. Firstly, the impact of drought stress on corn growth and development shows a gradient effect, with the most significant effects observed during the elongation stage and tasseling stage. Notably, Soil and Plant Analyzer Development (SPAD) and Leaf Area Index (LAI) are significantly affected during the silking stage, while plant height and stem width remain relatively unaffected. Secondly, spectral feature analysis reveals that, from the elongation stage to the silking stage, canopy reflectance exhibits peak–valley variations. Drought severity correlates positively with reflectance in the visible and shortwave infrared bands and negatively with reflectance in the near-infrared band. Canopy spectra during the silking stage are more affected by moderate and severe drought stress. Thirdly, LAI shows a significant positive correlation with yield, indicating its reliability in explaining yield variations. Finally, the yield-related drought index (YI) constructed based on Convolutional Neural Network (CNN), Random Forest (RF) and Multiple Linear Regression (MLR) methods has a good effect on revealing drought characteristics (R = 0.9332, p < 0.001). This study underscores the importance of understanding corn responses to drought stress at various growth stages for effective yield prediction and agricultural management strategies. Full article

Urban roads can effectively handle peak flows during extreme storms by serving as surface flood passages, provided the flow remains within safety thresholds for vehicles and pedestrians. However, studies on flow allocation at crossroad intersections are limited. Previous research has overlooked important factors: road transverse slope and turning radius. This study built a “two in, two out” laboratory crossroad intersection to examine flow allocation patterns. Experiments explored the effects of road longitudinal slope, boundary conditions, and the combined influence of turning radius and side slope. The results indicated that at flatter slopes, flow allocation is more influenced by road slope, while at steeper slopes, the inflow Froude number ratio becomes more significant. The combined effect of the turning radius and side slope results in a flow allocation that differs by 44.3% compared to rectangular orthogonal channel intersections. A straightforward formula is proposed to calculate the flow allocation ratio based on experimental results and inflow power ratio. These findings could improve road intersection designs for better flood mitigation, offering a practical tool for planning flood-resilient road networks. Full article

Forest fires are a major global environmental problem, especially for forest ecosystems and specifically in Mediterranean climate zones. These fires can seriously impact hydrologic processes and soil erosion, which can cause water pollution and flooding. The aim of this work is to assess the effect of forest fire on the hydrologic processes in the soil, depending on soil properties. For this purpose, the infiltration rate has been measured by ring infiltration tester, and the hydrophobicity has been quantified by the “water drop penetration time” method in several soils of burnt and unburnt forest areas in the Mediterranean mountains. The infiltration rates obtained are higher in burnt than in unburnt soils (1130 and 891 mm·h⁻¹, respectively), which contradicts most of the research in Mediterranean climates in southeast Spain with calcareous soils. Burnt soils show no hydrophobicity on the surface, but it is there when the soil is excavated by 1 cm. Additionally, burnt soils reveal a low frequency of hydrophobicity (in less than 30% of the samples) but more severe hydrophobicity (above 300 s); whereas, in unburnt soils, the frequency is higher (50%) but the values of hydrophobicity are lower. The results obtained clearly show the infiltration processes modified by fire, and these results may be useful for land managers, hydrologists, and those responsible for decision-making regarding the forest restoration of burnt land. Full article

Water level forecasting has significant impacts on transportation, agriculture, and flood control measures. Accurate water level values can enhance the safety and efficiency of water conservancy hub operation scheduling, reduce flood risks, and are essential for ensuring sustainable regional development. Addressing the nonlinearity and non-stationarity characteristics of gate-front water level sequences, this paper introduces a gate-front water level forecasting method based on a GRU–TCN–Transformer coupled model and permutation entropy (PE) algorithm. Firstly, an analysis method combining Singular Spectrum Analysis (SSA) and Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) is used to separate the original water level data into different frequency modal components. The PE algorithm subsequently divides each modal component into sequences of high and low frequencies. The GRU model is applied to predict the high-frequency sequence part, while the TCN–Transformer combination model is used for the low-frequency sequence part. The forecasting from both models are combined to obtain the final water level forecasting value. Multiple evaluation metrics are used to assess the forecasting performance. The findings indicate that the combined GRU–TCN–Transformer model achieves a Mean Absolute Error (MAE) of 0.0154, a Root Mean Square Error (RMSE) of 0.0205, and a Coefficient of Determination (R²) of 0.8076. These metrics indicate that the model outperforms machine learning Support Vector Machine (SVM) models, GRU models, Transformer models, and TCN–Transformer combination models in forecasting performance. The forecasting results have high credibility. This model provides a new reference for improving the accuracy of gate-front water level forecasting and offers significant insights for water resource management and flood prevention, demonstrating promising application prospects. Full article

Watercress (Nasturtium officinale R.Br.) is a cruciferous aquatic vegetable that possesses significant nutritional value. The NAC family is a transcription factor family specific to plants that play an important role in regulating plant responses to abiotic stress. In order to investigate the response of NAC genes to flooding stress in watercress, we conducted a study on the NoNAC family. In this study, a total of 119 NoNAC genes were obtained through genome-wide identification. Phylogenetic analysis indicated that the NoNAC family members can be categorized into ten subgroups. The results of gene structure analysis revealed that each branch within the subgroups exhibited similar motif composition and gene structure. The heatmap analysis showed that several NoNAC genes demonstrated tissue-specific expression patterns, suggesting their potential as regulators of associated tissue development. As an aquatic plant, watercress serves as a valuable material for investigating plant resistance to flooding stress. This study found that flooding can significantly increase the watercress plant height, which is a typical escape strategy under flooding. The analysis of the expression of NoNAC genes in the stem transcriptome after flooding indicated that only NoNAC36a consistently exhibited significant differential changes and down-regulated expression at the three time points of flooding treatment. This suggests that NoNAC36a may be involved in regulating watercress plant height increases under flooding stress. The utilization of a virus-induced gene silencing assay to investigate the biological function of NoNAC36a revealed that NoNAC36a silencing caused cell elongation and expansion, thus increasing watercress plant height. The yeast one-hybrid and dual luciferase assays demonstrated that NoNAC36a binds the promoter of NoXTH33 and inhibits its expression. Subsequently, the results of yeast two-hybrid, luciferase complementary, and pull-down assays revealed the interaction between NoMOB1A and NoNAC36a in vivo and in vitro. Sequence alignment indicated that NoMOB1A and AtMOB1A share an identical amino acid sequence. RT-qPCR analysis indicated that flooding prompted the expression of NoMOB1A in stems. Thus, it is speculated that NoMOB1A may exhibit functions similar to AtMOB1A and that the up-regulation of NoMOB1A expression in stems may facilitate an increase in plant height under flooding. In summary, the NoNAC family was analyzed, and revealed a regulatory network centered on NoNAC36a that facilitates watercress resistance to flooding stress. This study enhanced the understanding of the NoNAC genes and established a theoretical foundation for investigating plant flooding tolerance. Full article

The water drive reservoir in Shengli Oilfield has entered a stage of ultra-high water cut development, forming an advantageous flow channel for the water drive, resulting in the inefficient and ineffective circulation of injected water. Therefore, the distribution characteristics of water drive flow channels and their controlled residual oil in ultra-high water cut reservoirs are of great significance for treating water drive dominant flow channels and utilizing discontinuous residual oil. Through microscopic physical simulation of water flooding, color mixing recognition and image analysis technology were used to visualize the evolution characteristics of water flooding seepage channels and their changes during the control process. Research has shown that during the ultra-high water content period, the shrinkage of the water drive seepage channel forms a dominant seepage channel, forming a “seepage barrier” at the boundary of the dominant seepage channel, and dividing the affected area into the water drive dominant seepage zone and the seepage stagnation zone. The advantage of water flooding is that the oil displacement efficiency in the permeable zone is as high as 80.5%, and the remaining oil is highly dispersed. The water phase is almost a single-phase flow, revealing the reason for high water consumption in this stage. The remaining oil outside the affected area and within the stagnant flow zone accounts for 89.8% of the remaining oil, which has the potential to further improve oil recovery in the later stage of ultra-high water cut. For the first time, the redundancy index was proposed to quantitatively evaluate the control effect of liquid extraction and liquid flow direction on the dominant flow channels in water flooding. Experimental data showed that both liquid extraction and liquid flow direction can regulate the dominant flow channels in water flooding and improve oil recovery under certain conditions. Microscopic physical simulation experiments were conducted through the transformation of well network form in the later stage of ultra-high water content, which showed that the synergistic effect of liquid extraction and liquid flow direction can significantly improve the oil recovery effect, with an oil recovery rate of 68.02%, deepening the understanding of improving oil recovery rate in the later stage of ultra-high water content. Full article

Due to the impact of climate change, the importance of urban flood analysis is increasing. One of the biggest challenges in urban flood simulations is the complexity of storm sewer networks, which significantly affects both computational time and accuracy. This study aimed to analyze and evaluate the impact of sewer network simplification on the accuracy and computational performance of urban flood prediction by comparing different rainfall runoff methods. Using the hyper-connected solution for urban flood (HC-SURF) model, two rainfall runoff methods, the SWMM Runoff method and the Surface Runoff method, were compared. The sewer network simplification was applied based on manhole catchment areas ranging from 10 m² to 10,000 m². The analysis showed that the computation time could be reduced by up to 54.5% through simplification, though some accuracy loss may occur depending on the chosen runoff method. Overall, both methods produced excellent results in terms of mass balance, but the SWMM Runoff method minimized the reduction in analytical performance due to simplification. This study provides important insights into balancing computational efficiency and model accuracy in urban flood analysis. Full article

Nitrogen injection technology has become an important production technology after water injection development in the karst fracture-vuggy reservoir in Tahe Oilfield. However, due to the influence of reservoir heterogeneity and the high mobility of gas fluid, nitrogen easily forms a dominant channel and gas channeling occurs, and the recovery effect time is short. Based on this, a visual surface karst model is designed and created to study nitrogen foam-assisted gas drive. The results show that after gas channeling occurs in the dominant channel of nitrogen flooding, foam injection-assisted gas flooding can improve oil recovery. In the longitudinal direction, foam-assisted gas drive mainly displaces the remaining oil because of gravity differentiation and the reduction of oil–water interfacial tension. In the horizontal direction, foam-assisted gas drive is mainly used to block the large pore cracks and dominant channels, promote the gas to turn into large tortuous and small cracks, and expand the swept efficiency of the gas. After forming the dominant channel, injecting 0.3 pv salt-sensitive foam with a gas–liquid ratio of 2:1 in the middle of the gas channel can improve the recovery rate of the model from 4% to about 25%, and the recovery rate can be increased by about 20%, which improves the effect of gas flushing and improves the development efficiency of the oil field at the same time. Full article

Flooding is the most pervasive hydrological disaster globally. This study presents a comprehensive analysis of torrential rain and flood characteristics across three major urban agglomerations (CY, MRYR, and YRD) in the Yangtze River Basin from 1991 to 2020. Utilizing satellite-derived microwave SSM/I data and CHIRPS precipitation datasets, this study examines the impacts of urbanization and climate change on flood risk patterns. The results showed: (1) In 1998, the MRYR had the highest flood risk due to heavy rainfall and poor flood control, but by 2020, risk shifted to the CY with rapid urbanization and more rainfall, while the YRD maintained the lowest risk due to advanced flood control. (2) The relationship between impervious surface area and flood risk varied by region. The CY showed a negative correlation (−0.41), suggesting effective flood mitigation through topography and infrastructure; the MRYR had a slight positive correlation (0.12), indicating increased risks from urban expansion; and the YRD’s weak negative correlation (−0.18) reflected strong flood control systems. This research underscores the imperative of strategic urban planning and effective water resource management to mitigate future flood risks and contributes valuable insights to ongoing efforts in flood disaster prevention and control within the Yangtze River Basin. Full article

During the ongoing studies designed to examine the fungal diversity present within the abandoned and flooded Escádia Grande gold mine (Góis, Portugal), we repeatedly isolated several specimens belonging to a Penicillium species. Molecular phylogenetic analysis, coupled with morphological observations, positioned this fungus within subgen. Penicillium sect. Paradoxa, series Atramentosa, pinpointing its identity as Penicillium mexicanum (the first record for mining soils and the country). Given the limited research conducted on Penicillia isolated from similar environments, the species genome was sequenced utilizing the Oxford Nanopore^® MinION^™ methodology and studied through bioinformatic analysis. The obtained genome has a size of 29.62 Mb, containing a 47.72% GC content, 10,156 genes, with 44 rRNAs and 178 tRNAs/tmRNAs, providing the first genomic resource for this microorganism. Bioinformatic analysis allowed us to identify multiple genomic traits that can contribute towards this species survival in these extreme environments, including the presence of high levels of major facilitator transporters (MFS), Zn (2)-C6 fungal-type DNA-binding domains, P-loop containing nucleoside triphosphate hydrolases, specific fungal transcription factors and sugar transporters. Furthermore, putative advantageous metabolic traits, such as methylotrophy, assimilatory nitrate and sulfate reduction abilities, were also detected. In addition, the results also highlighted a strong genomic and metabolic organization and investment towards arsenic detoxification (transport and oxidation). Lastly, thirty-two putative biosynthetic gene clusters were predicted, including some with high similarity values to monascorubrin, nidulanin A, histidyltryptophanyldiketopiperazine/dehydrohistidyltryptophanyldiketopiperazine/roquefortine D/roquefortine C/glandicoline A/glandicoline B/meleagrine, YWA1 and choline. Overall, this study expands the current Penicillia knowledge from mining environments while also enhancing our understanding regarding fungal arsenic resistance. Full article

Farmers have a pivotal responsibility in soil conservation: they can either preserve or deplete it through their choices. The responsibility of agriculture increases when practised in delicate ecosystems, such as lagoonal ones. The Venetian Lagoon islands, which are increasingly subjected to natural and anthropic subsidence, occasional flooding events (acqua alta), and eustatic sea level rise, are constantly exposed to erosive processes that challenge farmers to play with their adaptive capability. This research was carried out on the islands of Sant’Erasmo and Vignole, the most representative of island agriculture in the Venetian Lagoon: they almost exclusively rely on agriculture, which is almost nil in the other islands. This empirical research aimed to explore farmers’ agricultural practices, perceptions of soil changes, and how they adapt to them. It was fundamental for this study that the field research involved direct human contact with farmers (through semi-structured interviews) for data collection and using qualitative methods for data analysis, integrating scientific and non-scientific forms of knowledge and actors. The final purpose was to demonstrate the sustainability (valued on the potential depletion or regeneration capability) of agricultural practices and adaptation strategies on a theoretical basis. Despite their polycultural landscape (maintained by low-input farming systems), escaped from the predominant landscape oversimplification, Sant’Erasmo and Vignole are also subjected to unsustainable agricultural practices, including heavy mechanisation and synthetic inputs. Coupled with natural soil salinity that is exacerbated by increasing drought periods, these practices can contribute to soil degradation and increased salinity. The reported adaptation strategies, such as zeroed, reduced, or more conscious use of machines, were guided by the need to reduce the negative impact of soil changes on productivity. Our research revealed some of them as sustainable and others as unsustainable (such as increasing irrigation to contrast soil salinity). Participatory action research is needed to support farmers in designing effective sustainable agricultural practices and adaptation strategies. Full article