Search Results (1,498)

Mountain regions are highly susceptible to severe hydro-meteorological events. These events induce substantial morphological changes that are preserved in the environment and cause significant economic losses, representing a major challenge for water resource management. Due to their abrupt nature, mitigating the impacts of such events requires preventive measures. The goal of the study was to comprehensively evaluate the impact of severe hydro-meteorological events on the mountain environment of the Ochotnica catchment, considering both environmental and economic aspects, over several years. This multi-year perspective also provided the opportunity to formulate some recommendations for the development of adaptation strategies for extreme hydro-meteorological events in mountain areas. The study demonstrates that delineation of the Maximum Probable Flood (MPF) hazard zone is a key element in building resilience to such events in mountain areas. Information related to the extent and depth of this zone, together with flow velocity, are critical components which may support actions aimed at reducing flood exposure and vulnerability, limiting the negative consequences of extreme hydro-meteorological events in mountain catchments prone to flash floods. Full article

Forecasting influent flow in Wastewater Treatment Plants (WWTPs) is critical for managing operational risks during flash floods, especially in Spain’s Mediterranean coastal regions. These facilities, essential for public health and environmental protection, are vulnerable to abrupt inflow surges caused by heavy rainfall. This study proposes a data-driven approach combining historical flow and rainfall data to predict short-term inflow dynamics. Several models were evaluated, including Random Forest, XGBoost, CatBoost, and LSTM, using metrics such as Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and R-squared (R²). XGBoost outperformed the others, particularly under severe class imbalance, with only 1% of the data representing rainfall events. Hyperparameter tuning and input window size analysis revealed that accurate predictions are achievable with just 14 days of training data from a 10-year (2012–2022) dataset sourced from a single WWTP and on-site weather station. The proposed framework supports proactive WWTP management during extreme weather events. Full article

The study aims to explore the causal relationships among climate, hydrological, and water quality variables in the Kiso River Basin, Japan, using a discrete Bayesian Network (BN) model. The BN was developed to represent probabilistic dependencies between climate factors (rainfall, air temperature), hydrological conditions (river flow levels), and water quality indicators (pH, dissolved oxygen [DO], electrical conductivity, ammonia, turbidity, organic pollution, and water temperature). The model used hourly monitoring data collected between 2016 and 2023, and the continuous variables were discretized based on national environmental thresholds to evaluate exceedance probabilities under different hydro-climatic scenarios. Results showed that air temperature strongly influenced water temperature, with a stabilizing effect under constant flow conditions. Rainfall and river flow were key drivers of turbidity; heavy rainfall and high flow increased the probability of exceeding turbidity thresholds by nearly 80%. Elevated ammonia levels during heavy rainfall and low temperatures reflected runoff and limited nitrification processes. Electrical conductivity decreased during high flows due to dilution, while dissolved oxygen was affected by low flows, turbidity, and temperature. As static BNs cannot model temporal dynamics, supplementary cross-correlation analyses were conducted to assess short-term responses among variables, revealing that most water quality parameters respond within ±24 h to changes in hydrological conditions. This study demonstrates that discrete BNs can effectively translate long-term monitoring data into practical, decision-relevant risk assessments to support adaptive water quality management in dynamic river systems. Full article

In the context of global climate change, frequent summer heavy rainfall events act as significant disturbances to the ecosystem functions of shallow lakes. This study examined the response of phytoplankton community structure and dynamics to heavy rainfall in Lake Changhu, a shallow eutrophic lake, through monthly monitoring during the summer months (June–August) of 2020–2022. The results revealed that heavy rainfall induced substantial water level fluctuations and shifts in key environmental parameters. Marked interannual variations were observed in the phytoplankton community, with the highest species richness in summer 2021 and lowest in 2022. While Chlorophyta dominated in species composition, Cyanobacteria overwhelmingly dominated in abundance, with key taxa including Dolichospermum flos-aquae L., Pseudanabaena limnetica L., Oscillatoria princeps V., Microcystis wesenbergii K., and Merismopedia minima B. Both phytoplankton abundance and biomass peaked in summer 2021. Community diversity indices were consistently lower in June compared to July–August, indicating higher environmental stress and a more simplified community structure during the initial rainfall period. A comprehensive water quality evaluation suggested that Lake Changhu was in a lightly to moderately polluted state. Correlation and redundancy analyses (RDA) identified rainfall, water temperature, and nutrient concentrations as the primary environmental drivers shaping phytoplankton community succession. These findings systematically elucidate the mechanistic responses of phytoplankton to heavy rainfall disturbances, offering a scientific foundation for ecological resilience assessment and adaptive management of shallow lakes under climate change. Full article

This study reveals the evolution of the mechanical behavior of tunnel lining under the influence of heavy rainfall through field monitoring and coupled fluid-solid numerical simulations. Field monitoring shows that after 14 h of rainfall, the maximum vertical tensile stress increment at monitoring point 2 reached 0.55 MPa. The simulation results indicate that when the rainfall intensity is 1.11 × 10⁻⁵ m/s and the rainfall duration lasts for 36 h, the principal stress increment at the sidewall monitoring point is 2.34 MPa (exceeding the tensile strength of C30 concrete of 1.43 MPa). Based on these findings, the suggested threshold for rainfall-induced checks is a single-day rainfall of ≥80 mm or continuous rainfall of ≥10 h. It is recommended to monitor once every 3 days during normal conditions and once every 2 h during heavy rainfall. When the permeability coefficient of the loosened zones increases from 2.05 × 10⁻⁶ m/s to 6.48 × 10⁻⁵ m/s, the principal stress at the sidewall decreases by 41%. It is suggested to reduce the blind drainage spacing on the sidewalls to 3–4 m. The model reproduces the observed stress increment within a 10% error margin. These results may provide a valuable reference for tunnel design, monitoring, and reinforcement in regions prone to heavy rainfall. Full article

This study conducts a diagnostic analysis of an extremely heavy rainfall event and its causative factors that occurred in Libya, North Africa on 10 September 2023. The Weather Research and Forecasting (WRF) model was also employed to perform some sensitivity experiments for this heavy rainfall event and further reveal its causes. Results indicate that the primary synoptic system responsible for this extreme precipitation event was an extratropical cyclone (storm) named “Daniel”. During the formation and development of this cyclone, the circulation at the 500 hPa level from the eastern Atlantic to western Asia exhibited a stable “two troughs and one ridge” pattern, with a upper-level cold vortex over the eastern Atlantic, a high-pressure ridge over central Europe, and a cut-off low over western Asia, collectively facilitating the formation and development of this cyclone. As this cyclone moved southward, it absorbed substantial energy from the Mediterranean Sea; following landfall, the intrusion of weak cold air enabled the cyclone to continue intensifying. Meanwhile, the northwest low-level jet stream to the west of the extratropical cyclone moved alongside the cyclone to the coastal regions of northeastern Libya, where it converged with water vapor transport belts originating from the Ionian Sea, the Aegean Sea, and the coastal waters of northeastern Libya. This convergence provided abundant water vapor for the rainstorm event, and under the combined effects of convergence and orographic lifting on the windward slopes of the coastal mountains, extreme precipitation was generated. In addition, the atmosphere over the coastal regions of northeastern Libya exhibited strong stratification instability, which was conducive to the occurrence of extreme heavy precipitation. Although WRF successfully reproduced the precipitation process, the precipitation amount was underestimated. Sensitivity experiments revealed that both the topography in the precipitation area and the sea surface temperature (SST) of the Mediterranean Sea contributed to this extreme heavy precipitation event. Full article

This paper, based on the CFD-DPM model coupled with sliding grid technology, constructs a simulation analysis method for the aerodynamic effects of propellers and wings under heavy rainfall. The mechanism of the influence of raindrops on the aerodynamic characteristics of this configuration is deeply analyzed, and the influence of the laws of different rainfall parameters is explored. The conclusion indicates that the local attack angle of the propeller decreases due to the influence of the falling speed of raindrops, resulting in a decrease in blade thrust and a maximum loss of 2.35%. The torque increases due to the increase in the rotational drag of the propeller. The maximum torque increment reaches 2.15%. With a decrease in the local angle of the attack and the effects of raindrop impact, film covering, and splashing, the maximum lift loss is 1.84%, and the drag increases by more than 12%. Raindrops will further influence the pitching, rolling, and yawing moment variation effect, combined with the rotation of the propeller. The greater the terminal velocity, diameter, and rainfall are, close to the surface of the propeller–wing combination configuration, the more severe the deterioration of the blade performance, and the stronger the lift reduction, drag increase, and moment variation effects of the wing. Full article

Under the dual pressures of global climate change and accelerated urbanization, the impacts of flood disasters on urban systems are becoming increasingly pronounced. Enhancing regional resilience has emerged as a critical factor in achieving sustainable urban development. Compared with existing methods such as CRITIC–Entropy, PCA–AHP, or SWMM-based resilience evaluations, grounded in urban resilience theory, this study takes Fangshan District in Beijing as empirical research to construct a post-flood disaster resilience evaluation index system spanning five dimensions (ecological, social, engineering, economic, and institutional) and leverages the integrated DEMATEL-TOPSIS-AISM model to synergistically identify key drivers, evaluate performance, and uncover internal hierarchies, thereby overcoming the limitations of existing research approaches. The findings indicate that the DEMATEL analysis identified the frequency of heavy rainfall (a12 = 0.889) and the proportion of flood disaster information databases (c51 = 1.153) as key driving factors. The TOPSIS assessment reveals that Fangshan District exhibits the strongest resilience in the economic dimension (Relative Closeness C = 0.21200), while the institutional dimension is the weakest (C = 0.00000), the AISM model constructs a hierarchical topology from a cause–effect priority perspective, elucidating the causal relationships and transmission mechanisms among factors across different dimensions. This study pioneers a novel perspective for urban resilience assessment, thereby establishing a theoretical foundation and practical references for enhancing flood resilience and advancing resilient city development. Full article

Understanding the impact of climate change and altered hydrologic cycles on regional water storage trends is crucial for predicting changes in recharge and streamflow and informing decisions regarding drought resilience and flood mitigation. While many regions have become drier under global climate change, the northeast United States has experienced an increased precipitation intensity, driving groundwater rise. This study integrates terrestrial water storage data from NASA’s Gravity Recovery and Climate Experiment (GRACE) satellites and soil moisture data from Soil Moisture Active Passive (SMAP), as well as long-term instrumental groundwater records from USGS groundwater monitoring wells, to understand the nature of storage trends. The results show that while aquifer-wide groundwater storage anomalies have stabilized in recent years, shallow groundwater and certain surface water bodies have accumulated about 0.6 cm of water annually, adding over 10 cm to the landscape, since 2005. These findings indicate that excess water from heavy rainfall is mainly stored in the shallow subsurface as perched aquifers and temporary wetlands rather than deep (5–30 m) aquifers. Understanding this change in storage is crucial for improving water resource management and adapting more effectively to a changing climate in the region. Full article

There are many types of probes available on the market for measuring ambient dose equivalent rates (ADERs), which makes intercomparison exercises essential to ensure data comparability and reliability. This study evaluated the performance of four widely used and similarly priced probes—the Reuter-Stokes ionization chamber, the RX04L from BITT, the MIRA from ENVINET, and the LB9360 from Berthold. The Reuter-Stokes ionization chamber was also taken as reference. Measurements were continuously conducted in Bilbao, northern Spain, during the period 2017–2021 under background conditions as well as during episodes of heavy rainfall and extreme temperatures. Results show that the BITT proportional counter exhibited the highest consistency with the Reuter-Stokes chamber under all meteorological conditions, and excellent stability even during extreme conditions. The Berthold probe displayed similar trends, but systematically overestimated dose rates, while the Geiger–Müller-based detector showed acceptable agreement under rainfall, but clear instability during temperature extremes. These findings highlight the importance of probe selection in environmental radioactivity networks as well as the use of reliable instruments for integration into modernized radiological surveillance systems. Full article

This study investigates the multi-scale processes associated with one type of typical heavy rainfall event in North China, focusing on the interplay among synoptic circulation, mesoscale dynamics, and topographic influences. The synoptic setting, characterized by the East Asian Great Trough, the South Asian High, and a northward-extended Western Pacific Subtropical High, created favorable conditions for moisture transport and convective activity. The event unfolded in two distinct phases: nocturnal and afternoon phases. During the nocturnal phase, an intensified 850 hPa low-level jet transported substantial meridional moisture into North China. Terrain-induced convergence along the Taihang Mountains enhanced lifting, resulting in concentrated precipitation at the foothills. In contrast, during the afternoon phase, the eastward movement of a Mongolian low trough and its associated cyclonic circulation shifted rainfall toward the plains east of the Taihang Mountains. Convective clusters developed locally due to surface heating and were organized along the low-level jet on the eastern flank of the cyclone, further intensifying precipitation. These results underscore three key mechanisms: nocturnal low-level jet-driven moisture convergence, synoptic-scale trough propagation, and terrain-modulated mesoscale convection. Understanding their diurnal variability offers valuable insights for operational forecasting, monitoring, and early warning systems for high-impact rainfall events in North China. Full article

Cloud liquid water content (CLWC) based on microwave radiometer data was investigated in this study. First, its consistency with radiosonde-based CLWC was established. Integrated CLWC was also checked against the liquid water path. CLWC performance in four weather types was considered: dense fog, clouds in spring, rainstorms, and typhoons. CLWC provides new insights into weather events. In particular, it could be useful for nowcasting low visibility associated with sea fog. It was also found to be inversely proportional to visibility in two cases of low visibility in Hong Kong. In springtime, low-level clouds and liquid water were found to exist extensively inside clouds. In rainstorm cases, supercooled cloud liquid water was absent during heavy rain but may exist within clouds when rain stops or light rain occurs. Similar observations were made in typhoon cases, namely during the direct impact of Typhoon Wipha on Hong Kong. Supercooled cloud liquid was present when outer rainbands of the typhoon affected Hong Kong with a smaller amount of rainfall. However, when Hong Kong was hit by a typhoon’s eyewall, rain was heavier, and supercooled liquid water was absent. These features are consistent with the radiosonde-based CLWC profiles. Radiometer-based CLWC is pseudocontinuous and provides additional insight into liquid water distribution in clouds under various weather conditions. Full article

The Bekasi River Basin is highly vulnerable to severe and recurrent flooding, as evidenced by significant infrastructure and environmental damage during major events. This study investigates the catastrophic floods of 2016, 2020, 2022, and 2025 by implementing the Rainfall-Runoff-Inundation (RRI) model to simulate key hydrological processes. After validation using historical water level data, the model performed effectively, achieving the highest coefficient of determination (R² = 0.75) and lowest root mean square error (RMSE = 0.66) at Cileungsi Station. In contrast, the lowest R² = 0.02, and the highest RMSE = 3.74 at Pondok Gede Permai (PGP) Station. The results reveal a concerning trend of worsening 5-year flood events, with the 2025 flood reaching a peak inundation depth exceeding 3 m and affecting an area of 2.97 km², caused by a rainfall threshold of more than 180 mm/day. Furthermore, the model shows a rapid hydrological response, with a time lag of approximately 7 h or less between peak rainfall and flood onset across three monitoring stations. Analysis indicates these severe floods were primarily triggered by heavy rainfall combined with significant land cover changes. The findings provide valuable insights for flood prediction and mitigation strategies in this vulnerable region. Full article

Heavy rainfall infiltration is a key disaster-inducing factor that triggers the softening of surrounding rock and deformation of support structures in tuff gully tunnels. Based on the gully section of the left line of the Dabao Tunnel of the Leigongshan–Rongjiang Expressway in Guizhou Province, this study systematically reveals the synergistic disaster-inducing mechanism of “topography-seepage-softening” in tuff gully tunnels under heavy rainfall infiltration through laboratory tests and FLAC3D 3D numerical simulations. The main innovative conclusions are as follows: (1) The “phased” attenuation law of tuff mechanical parameters was quantified, and the critical water content for significant strength deterioration was determined to be 2.5%, with a saturated softening coefficient of 0.59. These results provide key data for early warning and evaluation of similar projects. (2) A “convergence-disorder” distribution pattern of pore water pressure controlled by gully topography was revealed. It was found that the rock mass directly below the aqueduct exhibits a disordered zone with downward-extending pore water pressure due to fluid convergence, with the maximum pore water pressure reaching 0.55 MPa. This clarifies the essence that tunnel stability is controlled by the coupling of topography and seepage field. (3) The key sensitive areas for tunnel stability—namely the gully bottom, arch haunches, and the area below the aqueduct—were accurately identified. The significant increase in displacement of these areas after rock stratum softening was quantified (e.g., the displacement at the crown of the secondary lining increased from 3 mm to 4 mm, and the influence range expanded to the arch haunches). This study clarifies the deformation characteristics and instability mechanism of tuff gully tunnels under heavy rainfall from two aspects: the “internal mechanism of rock mass softening” and the “external condition of topographic seepage control.” It can provide a theoretical basis and key technical pathway for disaster prevention and control as well as stability design of similar tunnels. Full article

In this study, aiming to determine the potential pollution risks to the soil foundation caused by permeable pavement after its operation, a fully permeable asphalt pavement system is constructed. Through an accelerated simulation of a three-year cumulative rainfall test, the cumulative characteristics of pollutants in the soil foundation of the permeable asphalt pavement were studied, and a risk assessment of heavy metal pollution was carried out. The results show that N and P pollution is relatively serious. TN and NH₄⁺-N decrease with the increase of the soil foundation depth (0–50 cm), and there is an obvious surface accumulation phenomenon. The average contents at a depth of 0–10 cm are 1219 mg/kg and 443 mg/kg, respectively. The content of TP first shows a decreasing trend and then an increasing one, and it faces the risks of surface accumulation and leaching loss in the middle and lower parts. Although the average contents of Cu, Pb and Zn at different depths all meet the requirements of the Soil Environmental Quality Standard (for agricultural land), they are all higher than the background values of soil elements in Jiangsu Province. Among them, Cu and Zn pose a considerable ecological risk to the environment, especially with serious enrichment in the surface layer. The above cumulative characteristics of pollutants in the fully permeable asphalt pavement provide reference value for extending the service life of the permeable pavement system. Full article