Storm Events Research Articles

The effect of continuous geomagnetic storms on enhancements of ultrarelativistic electrons in the Earth’s outer radiation belt

The effect of continuous geomagnetic storms on enhancements of ultrarelativistic electrons in the Earth’s outer radiation belt

Observations of wave run-up affected by dune scarp during storm conditions: a two dimensional large-scaled movable bed experiment

Artificial dunes serve as essential nature-based defenses against the increasing threats posed by climate change and rising sea levels along coastal regions. However, these man-made dunes are particularly susceptible to erosion during severe storm events, necessitating careful consideration of their design for effective coastal protection. Among the myriad factors influencing artificial dune design, wave run-up stands out as a paramount concern. Not only is wave run-up crucial in assessing the extent of coastal flooding, but it also plays a significant role in shaping shoreline dynamics. During intense storm events, wave run-up amplification leads to substantial erosion of sand dunes, forming dune scarps that resemble cliffs. To address these challenges, we conducted a series of innovative two-dimensional large-scale laboratory experiments using movable beds. These experiments aimed to provide a quantitative understanding of wave run-up characteristics on dune scarps. Additionally, our study explored the feasibility of using existing empirical formulas to predict the 2% exceedance of wave run-up (referred to as R2%) in such scenarios. Our results revealed a consistent trend in R2% values, irrespective of variations in the surf similarity parameter when wave run-up was influenced by a dune scarp. Notably, our findings recommend the adoption of the Stockdon empirical formula, incorporating beach slope from the still water level to the dune scarp toe, as an effective method for predicting R2% during highly erosive conditions. This approach can significantly enhance the design and functionality of artificial dunes, bolstering their capacity to safeguard coastal areas from the impacts of severe storms and erosion, thus contributing to resilient coastal ecosystems and sustainable coastal management.

Catchment-Scale Hydrologic Effectiveness of Residential Rain Gardens: A Case Study in Columbia, Maryland, USA

To mitigate the adverse impacts of urban stormwater on streams, watershed managers are increasingly using low-impact development and green infrastructure (LID-GI) stormwater control measures, such as rain gardens—vegetated depressional areas that collect and infiltrate runoff from rooftops and driveways. Their catchment-scale performance, however, can vary widely, and few studies have investigated the cumulative performance of residential rain gardens for event runoff control in intermediate-sized (i.e., 1–10 km2) suburban catchments. We modeled three years of continuous rainfall-runoff from a 3.1 km2 catchment in Columbia, MD, USA, using the Storm Water Management Model (SWMM). Various extents of rain garden implementation at residential houses were simulated (i.e., 25%, 50%, 75%, and 100% coverage) to determine the effects on peak flow, runoff volume, and lag time. On average, treating 100% of residential rooftops in the catchment reduced peak flows by 14.3%, reduced runoff volumes by 11.4%, and increased lag times by 3.2% for the 223 rainfall events during the simulation period. Peak flow reductions were greater for smaller storm events (p < 0.01). Our results show that residential rain gardens can significantly improve the runoff response of suburban catchments, and that they represent an effective and relatively low-cost option for urban watershed management and restoration.

Understanding the role of biofilms and estimation of life-span of a tire derived aggregates-based underground stormwater treatment system

The importance of biofilm in tire derived aggregates (TDA) based underground systems has been investigated in this paper, to assess the utilization of tire waste as a cost-effective and sustainable resource for stormwater treatment. The primary objective of this study is to look into the role of biofilms in preventing metal leaching from a TDA based stormwater treatment system and to estimate the life span of a TDA based stormwater treatment system. TDA subjected to different influents to promote or limit the growth of biofilms were analyzed for their leaching and adsorption potential for fifteen different metals through 72 flushes, which is representative of roughly 9 years of TDA exposure to storm events in the upper Midwest USA. Biofilm growth on a manufacturing byproduct (wire exposed-TDA) was higher than on the traditional TDA. The presence of biofilm on TDA had a minor impact on orthophosphate adsorption as observed in a previous study conducted by the authors. However, metals such as iron, zinc and copper, which were previously a concern, had substantially lower leaching into the stored runoff. In addition, the orthophosphate removal from runoff by TDA with a biofilm through 72 flushes indicates that TDA based underground systems can have orthophosphate removal life span beyond 8–9 years. Thus, TDA with biofilms in an underground storage/infiltration chamber has the potential to establish itself as a sustainable, cost-effective, and long life-span alternative for stormwater remediation of orthophosphate pollution without leaching of metals.

Magnetospheric Time‐History in Storm‐Time Magnetic Flux Dynamics: A Global Simulation Campaign

AbstractThis paper aims to quantify the magnetospheric magnetic flux contents under moderate to intense space weather conditions using global simulations. This study is a companion to Akhavan‐Tafti, Atilaw, et al. (2023, https://doi.org/10.1029/2023JA031832) where magnetic flux evolution is presented for a catalog of storm events, using Heliophysics System Observatory (HSO) observations. For this study, we used the Space Weather Modeling Framework (SWMF) in Geospace configuration to study magnetic flux dynamics for a subset of their storm events (15 events). Simulations reliably resolve the storm‐time magnetic flux Bz and current density |J| asymmetries across the different storm phases. It is revealed that: relative to the quiet period, flux content is enhanced during the storm sudden commencement (SSC) phase in the dayside by ΔBz/Bz, quiet = +17%, and reduced in the nightside magnetosphere (r[RE] < −6 RE) by −15%. At the same time, the cross‐tail current is found to enhance (|J| = 2 nA/m2), which suggests the storm impact in the nightside magnetosphere is much earlier in the storm cycle than previously shown. Concurring with previous studies, a significant depletion of magnetic flux by up to −40%, with day‐night and dawn‐dusk asymmetries, can be seen during the main and recovery phases. This corresponds to the enhanced current density (|J| = 5–8 nA/m2) at ∼6 RE further confirming the role of ring current in driving magnetospheric dynamics during the main and recovery phases. This is in contrast with the SSC phase wherein the Chapman‐Ferraro and cross‐tail currents are the dominant current systems.

Rainfall analysis and deriving design storm for hydrological modelling of Koyna dam catchment area in Maharashtra state of India

Rainfall is a key hydro meteorological variable. Climate change is disrupting the hydrological cycle and altering the usual cycle of rainfall, which frequently results in long-lasting storms with significant rainfall. A first step in hydrologic design of project is to determine the design storm or rainfall events to be used. For deriving design storm, researchers concluded that instead of using generalized readily available curves or maps, it is better to estimate design storm based on site specific historical rainfall data. The objective of the study is to analyze the rainfall data in the koyna watershed area in order to evaluate the design storm, which will be further used as an input data for HEC-HMS event based hydrological modelling of flood peak attenuation of design storm flow at koyna dam during extreme rainfall event.In this study, 40 years (1982–2021) of rainfall data from 8 rain gauge stations in Koyna Dam Catchment area is used initially for performing trend analysis through statistical and graphical techniques and then for Isopluvial analysis. The Sen's slope test and the Mann-Kendall test are the statistical techniques employed, and Innovative Trend Analysis is the graphical technique used. IDF approach is used for deriving design storm, and using Gumbel's frequency distribution method Isohyetal maps, IDF tables and curves are prepared for 2,10,25,50,75 and 100 year return periods and 6,12,24,48 and 96 h durations. Results obtained from statistical and graphical trend analysis of annual rainfall series are consistent. No statistically significant trend in annual rainfall series is observed, however there is rising and falling trend was observed in annual as well as monthly rainfall series.From the results of design storm study, the design storm hyetograph of 10 years return period and 96 h duration is selected, which gives the rainfall intensity of 10.88 mm/h for the koyna catchment. There are various dams nearby koyna catchment, The Isohyet maps, IDF curves and table output available from this study can be more reliably used during planning and design of hydraulic structure for other areas near by koyna catchment.

Distribution of ozone, carbon monoxide and oxides of nitrogen over an urban location in the foothills of the North-Western Himalayas

Increasing anthropogenic activities and biomass burning events over the Northern Indian region severely affect the pristine environment of North-Western Himalayas. To investigate their influence in this data sparse region, continuous monitoring of O3, CO and NOx are made during January 2018 to December 2019 over Dehradun, an urban location in the foothills of North-western Himalayas. Ozone shows daytime broad peak and CO and NOx show two peaks during morning and evening hours. The maximum daytime ozone is observed during spring with 58.2 ± 2.0 ppbv (56.2 ± 2.7 ppbv) during 2018 (2019). CO and NOx show maximum value during winter and minimum during summer-monsoon. Their concentrations are found to be influenced from stubble burning and forest fire emissions during late spring. WRF-Chem simulations are made with and without biomass burning emissions to quantify the contribution of these emissions on the variability of these gases over Dehradun. Sensitivity simulations reveal that biomass burning over northern Indian region contributed 43 ppbv, 79 ppbv and 1.2 ppbv increase in O3, CO and NOx mixing ratios over Dehradun. In addition, dust storm event in June 2018 contributed for lower ozone levels in 2018 (16.1 ± 9.3 ppbv) and stratosphere troposphere exchange process enhanced surface ozone in June 2019 (53.6 ± 22.3 ppbv).

Lithofacies Characteristics of Continental Lacustrine Fine-Grained Sedimentary Rocks and Their Coupling Relationship with Sedimentary Environments: Insights from the Shahejie Formation, Dongying Sag

Lacustrine fine-grained sedimentary rocks in the Dongying Sag of the Bohai Bay Basin in China exhibit significant potential for hydrocarbon exploration. This study investigates the lithofacies types and sedimentary evolution of the Paleogene Shahejie Formation’s lower third member (Es3l) and upper fourth member (Es4u), integrating petrological and geochemical analyses to explore the relationship between lithofacies characteristics and sedimentary environments. The results show that the fine-grained sedimentary rocks in the study area can be classified into 18 lithofacies, with seven principal ones, including organic-rich laminated carbonate fine-grained mixed sedimentary rock lithofacies and organic-rich laminated limestone lithofacies. In conjunction with analyses of vertical changes in geochemical proxies such as paleoclimate (e.g., CIA, Na/Al), paleoproductivity (e.g., Ba), paleosalinity (e.g., Sr/Ba), paleo-redox conditions (e.g., V/Sc, V/V + Ni), and terrigenous detrital influx (e.g., Al, Ti), five stages are delineated from bottom to top. These stages demonstrate a general transition from an arid to humid paleoclimate, a steady increase in paleoproductivity, a gradual decrease in paleosalinity, an overall reducing water body environment, and an increasing trend of terrestrial detrital input. This study demonstrates that the abundance of organic matter is primarily influenced by paleoproductivity and paleo-redox conditions. The variations in rock components are predominantly influenced by paleoclimate, and sedimentary structures are affected by the depth of the lake basin. Special depositional events, such as storm events in Stage II, have significantly impacted the abundance of organic matter, rock components, and sedimentary structures by disturbing the water column and disrupting the reducing conditions at the lake bottom. The present study offers crucial insights into the genesis mechanisms of continental lacustrine fine-grained sedimentary rocks, facilitates the prediction of lithofacies distribution, and advances the exploration of China’s shale oil resources in lacustrine environments.

Statistical analysis of the relationships between boundary layer meteorological processes and nocturnal O3 increases in Beijing from 2018 to 2022

In the absence of photochemical reactions, nocturnal ozone (O3) variation was found to be caused by boundary layer meteorological processes. In addition to low-level jet (LLJ) and convective storm (CS) events, cold front and foehn processes also cause nocturnal O3 increases (NOIs). The subsidence warming effect (Subsi.) caused by weak cold front and foehn processes cause the nocturnal surface temperature and O3 to increase. Statistical analysis revealed that NOI days accounted for 39.4 ± 6.4% of the total number of days per year in Beijing, and the average occurrence frequency decreased by 1.7%/year over a recent five-year period (2018–2022). The LLJ process is the primary factor causing NOIs, and the average annual contributions of the LLJ, CS and Subsi. processes to NOIs were approximately 32.2 ± 10.5%, 11.7 ± 2.3% and 8.0 ± 3.0%, respectively. From a seasonal point of view, the most NOI events occurred in summer, and the least occurred in autumn. LLJs contributed the most to the NOIs in each season, and the CS contribution was almost equal to that of LLJs in summer. LLJs that occurred near 00:00 LT and 04:00 LT had a greater probability of causing NOI events. Most of the nocturnal CS events occurred during 22:00 LT-02:00 LT (next day), and the contribution of CSs to NOIs fluctuated around 10.0%. More than half (68.0%) of the Subsi. events occurred during 23:00 LT-03:00 LT (next day). Subsi. events occurred during this period contributed more to NOIs than other periods. Meteorological processes more easily caused NOI events in the urban, Daxing and Tongzhou districts than other areas. The average surface O3 concentration during the early morning hours (04:00–06:00 LT) on NOI days was 8.8 ± 3.2 μg/m3 higher than that on non-NOI days, suggesting that NOIs can elevate the base O3 concentration during the following day.

Evaluation of an experimental kelp farm’s structural behavior using regression modelling and response amplitude operators derived from in situ measurements

An experimental kelp farming system for exposed ocean conditions was designed, deployed, planted with kelp and instrumented for evaluation of its dynamic response to ocean waves, tides, and currents. The farm featured a novel “lattice” mooring design and anchor lines and cultivation lines (horizontal lines used as kelp growth substrate) made of fiberglass rods. The farm was deployed at a site in Saco Bay, Maine with 13 m (MLLW) water depth. There the farm was exposed to waves with heights up to 5.9 m. Anchor line tension, tide and wave height time series were gathered and processed into response amplitude operators (RAOs) and least squared error linear regression models enabling recognition of meaningful patterns between the forcing factors and the mooring response. Mean mooring line tensions were shown to increase nonlinearly with tide. Anchor line tension response amplitudes were shown to exhibit high sensitivity to both low and high frequency wave forcing. Numerical free-release test simulations suggested natural frequencies in heave of 0.91 Hz, indicating that tension response sensitivities at high frequency could be the result of resonance. Low frequency tension response disproportionate to the low frequency wave forcing could be explained by wave forcing on kelp cultivation arrays modulated by wave group envelopes. Instances of high magnitude, potentially damaging peak tensions, deemed shock loads, were prevalent in most load cases. Anchor line tension dynamics including RAO and shock load magnitudes were shown to be sensitive to mooring stiffness (ratio of tension to resulting elongation) and, in some cases, significant wave amplitude. Patterns of anchor line response indicated that additional mooring elasticity or geometric compliance and use of floatation with less sensitivity to high frequency waves could help avoid the cause of and costly consequences of amplified high frequency loading and high amplitude shock loading. RAOs and regression model results also indicated a subdued response in frequencies associated with ocean swell waves, suggesting desirable performance in waves most dominant in extreme storm events. With the proposed improvements, the farm system design suggests merit as a robust and durable macroalgae biomass production platform.

SPATIOTEMPORAL VARIABILITY OF HYDROLOGICAL CHARACTERISTICS IN THE MIXING ZONE OF THE PREGOLYA RIVER (SOUTH-EASTERN BALTIC) AND METHODOLOGICAL APPROACHES TO ITS STUDY

SPATIOTEMPORAL VARIABILITY OF HYDROLOGICAL CHARACTERISTICS IN THE MIXING ZONE OF THE PREGOLYA RIVER (SOUTH-EASTERN BALTIC) AND METHODOLOGICAL APPROACHES TO ITS STUDY

Data-Driven Assessment of the Impact of Hurricanes Ian and Nicole: Natural and Armored Dunes in the Aftermath of Hurricanes on Florida’s Central East Coast

Hurricanes Ian and Nicole caused devastating destruction across Florida in September and November 2022, leaving widespread damage in their wakes. This study focuses on the assessment of barrier islands’ shorelines, encompassing natural sand dunes and dune vegetation as well as armored dunes with man-made infrastructure such as seawalls. High-resolution satellite imagery from Planet was used to assess the impacts of these hurricanes on the beach shorelines of Volusia, Flagler, and St. Johns Counties on the Florida Central East Coast. Shorefront vegetation was classified into two classes. Normalized Difference Vegetation Index (NDVI) values were calculated before the hurricanes, one month after Hurricane Ian, one month after Hurricane Nicole, and one-year post landfall. LiDAR (Light Detection and Ranging) was incorporated to calculate vertical changes in the shorelines before and after the hurricanes. The results suggest that natural sand dunes were more resilient as they experienced less impact to vegetation and elevation and more substantial recovery than armored dunes. Moreover, the close timeframe of the storm events suggests a compound effect on the weakened dune systems. This study highlights the importance of understanding natural dune resilience to facilitate future adaptive management efforts because armored dunes may have long-term detrimental effects on hurricane-prone barrier islands.

High-Resolution Interannual Evolution of the Dune Toe at a Mesotidal Barrier (Camposoto Beach, SW Spain)

Over recent years, processes related to marine storms, sediment shortages and human intervention have caused the global retreat of many coastal systems and the degradation of their dunes. In this context, changes in the dune toe are commonly used as a proxy to study the interannual shoreline evolution, and it is usually analyzed using orthophotography, while high temporal- and spatial-scale resolution studies of dune toe evolution are not frequent. In this work, a quasi-monthly study of dune toe data was carried out between 2008 and 2018. These data, taken from the RTK-DGPS and UAS systems, were subjected to shoreline analysis, and they showed an average regression rate of −2.30 m/year, a higher value than the one registered until 2008 (1 m/year). This suggests an acceleration in the erosion suffered within the system, which was revealed to be more intense in the northern sector of the study area. Dune toe variability increased over the years, probably due to the presence of washover fans breaking the foredune that were reactivated and expanded during storm events. The ephemeral progradation of the dune toe was also noted, which could be explained with reference to wind events and/or beach nourishment that had been carried out over the studied period. From the analysis of the dune toe elevation, a decrease in this variable was obtained, especially in the areas affected due to washover fans. This finding is supported by the significant correlation of the dune toe elevation and erosion trend, suggesting that the areas where the dune toe was lower are prone to suffering a greater retreat. This correlation provides insight into the future evolution of the barrier, suggesting a state of degradation and a transition to a lower-resilience state.

Climate Change and Cholera: A Review Exploring the Association Between Storm Severity and Global Human Vibrio spp. Incidence.

Current global meteorological evidence suggests that climate change is a direct contributor to the increased severity of weather events, such as hurricanes and typhoons, putting billions of people at increased risk of physical harm, property damage, and destructive flooding. When flood water becomes stagnant, communities are more susceptible to a multitude of infectious diseases, ranging from mosquito-borne parasites to bacterial infections. In the case of Vibrio spp., a bacterial pathogen class with an infamous history of waterborne illness, recent data has demonstrated the ability for salt water, fresh water, and brackish water replication, creating ideal conditions for spread after a tropical cyclone. Vibrio spp. infections, specifically species V. vulnificus, V. parahaemolyticus, and V. cholerae, have shown significant upticks in the number of global cases, with some species increasing in incidence by more than 8-fold in the last 40 years. These outbreaks are contained mainly in areas susceptible to large-scale storm events and primarily occur during or immediately following the conclusion of local storm seasons, suggesting a potential correlation between the presence of tropical weather events and increases in the number of human Vibrio infections. In this review, we present a compilation of sources from tropical cyclone-susceptible areas, including the Americas, Asia, Africa, and Oceania, containing evidence demonstrating that recent outbreaks of Vibrio spp. are correlated with an increase in the severity of storms. Many of the included studies used modeling to forecast future trends of vibriosis and, therefore, directly link the effects of climate change with detrimental impacts to human global health.

Brief report of fatal rainfall-triggered landslides from record-breaking 2023 storms in Auckland, New Zealand

The aim of this paper is to report on fatal landslides resulting from two extraordinary storm events in January and February 2023, in Auckland, New Zealand, including the characteristics of the terrain, the site geology, and the storms. The January 27 Auckland Anniversary storm was from an “atmospheric river,” dumping Summer’s worth of rain (265 mm) in one day. This was the highest 24-h total on record, estimated a 1 in 200-year event, with a peak 2-min rainfall of 4.2 mm, coinciding with Friday’s evening “rush hour.” This led to widespread landsliding throughout Auckland, including a fatal landslide in Parnell, central Auckland. Notably, this occurred only meters from a similarly destructive landslide in 1997. With January 2023 Auckland’s wettest January on record, and with the region still in a state of emergency, Tropical Cyclone Gabrielle crossed the region on February 13–14. This also caused widespread landsliding, including a fatal landslide at Muriwai on the west Auckland coast. Fatal landslides from the same escarpment had occurred in 1965, close to the February 13, 2023, fatal landslide. Taken together, both storm events caused > 140,000 landslides across the North Island, and flooding, making hundreds of people homeless, with damage estimates of > US$8.6 billion (3.4% of NZ’s GDP). For future disaster risk reduction, attention should be paid to revising legislation and local planning, which currently allows people to legally build (and re-build) houses in landslide-prone areas of New Zealand.

Monitoring the impacts of rainfall characteristics on sediment loss from road construction sites

Exposed soils associated with active construction sites provide opportunities for erosion and sediment transport during storm events, introducing risks associated with excess sediment to downstream infrastructure and aquatic biota. A better understanding of the drivers of sediment transport in construction site runoff is needed to improve the design and performance of erosion and sediment control measures (ESCMs). Eleven monitoring locations on 3 active road construction sites in central Ohio were established to characterize runoff quality from points of concentrated flow during storm events. Grab samples were analyzed for total suspended solids (TSS), turbidity, and particle size distribution (PSD). Median TSS concentrations and turbidity levels across all samples were 626 mg/L (range 25–28,600 mg/L) and 759 NTU (range 22–33,000 NTU), respectively. The median PSD corresponded to a silty clay loam, mirroring the soil texture of much of Ohio’s subsoils. TSS concentrations and turbidity were significantly positively correlated with the rainfall intensity 10 min prior to sample collection, suggesting that higher flow rates created greater shear stress on bare soil which resulted in more erosion. Conversely, rainfall duration was negatively correlated with particle size, indicating that prolonged moisture from rainfall promoted the dispersion of soil aggregates which mobilized smaller particles. Multivariable linear regression models revealed that higher rainfall intensities corresponded to higher turbidity values, while higher TSS concentrations were associated with higher rainfall intensities, depths, and durations. Results from this study highlight the importance of reducing raindrop impact and subsequent shear stress applied by concentrated flows through the use of ESCMs to limit sediment export from construction sites.

Deltaic marsh accretion under episodic sediment supply controlled by river regulations and storms: Implications for coastal wetlands restoration in the Yellow River Delta

Sediment supply has long been recognized as a critical factor affecting salt marsh evolutions. Subject to fluctuating river discharges and coastal hydrodynamics, sediment supply to deltaic marshes are episodic rather than continuous. To evaluate the impacts of episodic sediment delivery under river regulations and storm events on deltaic marsh accretion, a 5-month (April 18th to September 4th, 2021) field campaign was conducted at a Spartina alterniflora marsh of the Yellow River Delta, China. Nine storm events and the Water-Sediment Regulation Scheme (WSRS) coinciding with a freshwater diversion were captured. It was found that the two phases of the WSRS differed greatly in their contribution to marsh accretion. During the Water-Regulation Phase (WRP), marsh accretion rates showed little difference with pre-WRP periods. However, the subsequent Sediment-Regulation Phase (SRP) contributed to ∼15 % of annual accretion within only 4 days, suggesting the SRP was more effective in nourishing deltaic marshes with sediment. Further analyses indicated that the higher accretion during SRP was attributed to both higher sediment concentrations and more favorable sediment pathways, influenced by delta-scale river-tide interactions. Observations also showed that storm events contributed to half of the marsh accretion during the non-WSRS period when the fluvial sediment supply was very low. During storms, wave-induced intertidal resuspension acted as the major sediment sources. Under favorable conditions (onshore wind, high water levels, high waves), tidal-averaged sediment delivery to marshes underwent as much as fifty-fold increase compared with the calm period. The observed marsh dynamics suggested that marsh sedimentations depended on not only the seaward sediment concentrations, but also the sediment transport pathways. For deltaic marsh restoration practices, we proposed that marsh-orientated schemes which align river regulations with favorable meteorological and hydrodynamic conditions, could potentially make better use of fluvial sediment for deltaic marsh nourishment.

Introducing a new hazard and exposure atlas for European winter storms

Winter storms are one of the riskiest natural hazards in Europe. They are often assessed either from a climatology perspective or the exposed land use type. However, for accurate storm protection management, analyzing compatible wind speed and land use data at the highest spatiotemporally accuracy is critical. Thus, the study goals were (1) modeling wind speed for the 27 most extreme winter storm events from 1993 to 2022 at high spatial resolution (250 m × 250 m) and (2) defining and developing new and representative storm hazard and storm exposure indices for forested area, built-up area, and population. The winter storm event-related wind speed was modeled using a least-squares boosting approach based on ERA5 reanalysis data and 1730 wind speed measurement sites from the integrated surface global hourly meteorological dataset. In combination with temporally variable population density, built-up area, and forested area grids, the storm exposure indices for the European NUTS3 regions were calculated. The coefficient of determination of the median of the modeled wind speed fields is 0.73 for an independent subset of measurement sites. The wind speed maps reveal the uniqueness of the winter storm events. Each storm only affects parts of Europe. The study also emphasizes the relevance of distinguishing between storm hazard and storm exposure. The exposure of built-up areas to winter storms has increased considerably in recent years. This example underlines that storm exposure is not temporally constant but depends on the development of wind speed and land use. Decision-makers can apply the results of this study to evaluate and improve the effectiveness of storm protection measures. The developed storm exposures indices enable a sector- and location-specific evaluation with high precision.

Towards evaluating the conditional probability of waterborne microbial risks associated with critical rainfall events following land application of animal waste — A focus on Irish pastures

ABSTRACT Modelling surface runoff and infiltration in an agricultural watershed is essential for understanding the nutrient cycle and water quality management. This research evaluates the critical rainfall events causing maximum surface runoff and infiltration. Empirical models such as Soil Conservation Service (SCS) curve number and Explicit Green-Ampt (EGA) were analysed for different soil hydraulic conditions and storm events with specific return periods. The present study forecasted the maximum daily rainfall and intensity as 113.6 mm and 19.9 cm h–1, respectively, considering a 100-year return period storm. The deterministic part of the model calculates the daily maximum surface runoff as 5.51 cm (from the SCS model). The EGA model revealed that the rainfall intensity of 0.143, 0.163, 0.175, 0.179, 0.181, 0.182, and 0.182 cm h−1 (duration of 24 h) was found critical for 1, 2, 5, 10, 25, 50, 100 year return period of the storm, respectively in different soil texture classes (sand, loamy sand, sandy loam, loam, silt loam, sandy clay loam, clay loam, silty clay soils). Exceptions imply for three occasions where the intensity of 0.407 cm h−1 and duration of 18 h produced maximum infiltration for silty clay loam, and intensity of 0.352 and 0.354 cm h−1 with 9 h rainfall (each) produced maximum infiltration for clay. The probabilistic model revealed that a daily storm event probability of 2.74 × 10–5 is associated with a simulated mean runoff depth of 0.69 cm and infiltration of 20.7 cm. Critical rainfall probabilities calculated in this study can be multiplied with the overall microbial/pollutant human health risk assessment framework to calculate conditional probability and better estimate microbial risk through the drinking water pathway. This study is very relevant for the wet climatic condition of Ireland, where most land use is pastures.

Evaluating barrier beach protection with numerical modelling. A practical case

Embryonic dunes, continuous dunes and classical beach nourishment are tested as soft coastal protection measures in the vulnerable Trabucador barrier beach located in the NW Mediterranean Sea against different storm conditions. The beach was impacted by severe breaching events during past storms. Evaluation of the performance of the dunes and nourishment as coastal protection measures for the barrier beach is carried out using XBeach model for three different storm events: Storm Isaak being a mid-tier double peak storm, Storm Filomena a typical larger storm of the region and Storm Gloria the largest ever storm to hit the region, with 7, 12 and 60 years of return period respectively. The model showed embryonic dunes and shoreface nourishment systems greatly protect the beach against Storm Isaak and Storm Filomena but did not withstand Storm Gloria considering it being almost 1.5 times larger than the second-highest storm in terms of significant wave height. The study aids in assessing the effectiveness of various mitigation actions for barrier beaches, with the aim of implementing them in practical field applications.