Series Of Storm Events Research Articles

Tidal Impoundment and Mangrove Dieback at Cabbage Tree Basin, NSW: Drivers of Change and Tailored Management for the Future

Major storms can cause significant changes to coastal and wetland environments. A series of storm events in 2020 resulted in closure of the historically open estuary at Cabbage Tree Basin, Port Hacking, New South Wales (NSW), Australia. Prolonged tidal impoundment (3 months) led to substantial changes in hydrological and sedimentological processes, resulting in widespread mangrove dieback. This study aimed to quantify the degree of impact and recovery for mangroves, identify factors contributing to dieback, and consider the implications for carbon sequestration. This was achieved using remotely piloted aircraft structure-from-motion approaches, aerial photography, and field-based assessments of vegetation health and above-ground biomass (AGB). Mangroves were classified as ‘dead’, ‘partially dead’, and ‘live’. In October 2019, there was 10.8 ha of live mangroves, with this reduced to 6.6 ha by August 2022. Digital surface models (DSMs) were intersected with classified mangroves to assess the vertical distribution of each zone. All mangroves classified as ‘dead’ were distributed at elevations < 0.4 m with respect to the Australian Height Datum (AHD), suggesting these regions were persistently inundated, which was confirmed by water level loggers (inundated during logger deployment). Field data confirmed substrate elevation related to dieback with the proportion of ‘live’ mangroves greatest at elevations > 0.6 m AHD. Substrate elevation and distance to the estuary mouth were significantly correlated with species, with Avicennia marina located at lower tidal positions and closer to the entrance compared to Aegiceras corniculatum. The dieback event equated to a loss of 81.5 ± 48 Mg of above-ground biomass, 38.1 ± 22.5 Mg C, or 140 ± 82 Mg CO2 equivalence (CO2e). This study provides an important baseline for monitoring dieback events. Continued monitoring is crucial to assess recovery and to tailor management strategies.

Drowning incidents and conditions due to hidden flash rips in Lake Michigan

Flash rips are episodic bursts of water jetting offshore, which can lead to drowning incidents by sweeping swimmers offshore without warning, thus posing a hidden and unrecognized danger to beachgoers. This study reveals hazards of flash rips by investigating a series of drowning incidents along coasts of Lake Michigan during a series of storm events on July 18–21, 2019. Occurrences and causes of flash rips were depicted through webcam image observations, storm features of atmospheric disturbances, hydrodynamic circumstances of wind waves and meteorologically induced water level fluctuations, and model-reconstructed nearshore circulations. Results shows that flash rips were generated during or after storms through nearshore processes of storm-induced wind waves and meteorologically induced water level fluctuations. With small wind waves, low water level fluctuations, and a timing delay of rip occurrences relative to the causative convective storms, flash rips pose a hidden hazard to unaware swimmers. Historical observations for incidents in Lake Michigan between 2002 and 2019 further show that dry conditions or fair weathers and a calm water signature at the beach can likely generate unexpected hidden flash rips, resulting in the highest drowning risks. There is an urgent need for communication, education, and prediction/forecast of hidden flash rips to the Laurentian Great Lakes and worldwide coastal communities.

Effect of rainfall uncertainty on the performance of physically based rainfall–runoff models

AbstractThis paper analyses the effect of rain data uncertainty on the performance of two hydrological models with different spatial structures: a semidistributed and a fully distributed model. The study is performed on a small catchment of 19.6 km2 located in the north‐west of Spain, where the arrival of low pressure fronts from the Atlantic Ocean causes highly variable rainfall events. The rainfall fields in this catchment during a series of storm events are estimated using rainfall point measurements. The uncertainty of the estimated fields is quantified using a conditional simulation technique. Discharge and rain data, including the uncertainty of the estimated rainfall fields, are then used to calibrate and validate both hydrological models following the generalized likelihood uncertainty estimation (GLUE) methodology. In the storm events analysed, the two models show similar performance. In all cases, results show that the calibrated distribution of the input parameters narrows when the rain uncertainty is included in the analysis. Otherwise, when rain uncertainty is not considered, the calibration of the input parameters must account for all uncertainty in the rainfall–runoff transformation process. Also, in both models, the uncertainty of the predicted discharges increase in similar magnitude when the uncertainty of rainfall input increase.

Selecting a series of storm events for a model-based assessment of combined sewer overflows

ABSTRACTThe hydraulic verification of combined sewer systems as well as the assessment of combined sewer overflows (CSOs) can be conducted using a hydrodynamic model. Unfortunately, long-term simulations with hydrodynamic models for the assessment of CSOs can cause unacceptably long computation times. Using only a series of storm events instead of a precipitation continuum can reduce this time and enables parallel simulation of single storm events. We introduce a method to select this series of storm events. The method’s parameters have been optimized to replicate the overflow volume of the continuous simulation and to minimize the overall computation time. This optimization revealed a generally applicable parameter set that results in series of storm events that are shorter than the precipitation continuum by 86.2–95.2% for the investigated cases. Additionally, the deviation of overflow volume between continuous simulation and series simulation ranges between only 0.1% and 4.1%.

Storm Warnings: The Eternally Recurring Apocalypse in Kate Chopin’s The Awakening

A characteristic of literary naturalism is the representation of limitations placed on the human will (Pizer 5), and while naturalistic readings of Kate Chopins The Awakening (1899) have recognized the way that social and biological forces circumscribe Edna Pontellier's potential to realize her version of self-fulfillment, they fall short of understanding the spatial histories of this post-apocalyptic novel's Gulf Island settings: Cheniere Caminada and Grand Isle. Critics such as Erik Margraf and Donald Pizer have read the novel's representation of Edna's Creole milieu and biology as deterministic forces, but they have found it difficult to account for the physical setting of the islands, which, at one time, represented a utopian promise of freedom from restrictive social conventions and mores for New Orleans and island residents. Margraf, for example, has conceded that unlike Edna's Creole milieu, which does restrict her freedom and determine her behavior, the island environment is not physically threatening in the way that the natural environment typically is in other naturalistic novels (101). By the time the novel was published in 1899, however, the utopianism of the island setting had been undermined by the Hurricane of 1893. As Barbara Ewell and Pamela Menke have convincingly argued, this hurricane was on Chopin's mind as she was writing The Awakening, but it has not yet come to the fore in critical discussions of the novel (6). Two thousand lives were lost in this hurricane on the Gulf Islands, including two thirds of the population on Cheniere Caminada, and because of the disaster, the resort culture on Grand Isle went into a steep decline (Ewell and Menke 4-5). As the was widely publicized in newspapers at the time and for several years thereafter, for many of Chopins contemporaries, the utopianism of the island culture would have seemed elusive and unstable from the moment they opened the novel, and Chopins narrative space mirrors the instability of this utopianism. The hurricane appears in a series of storm events, or figurative imaginings of the Hurricane of 1893, within a post-apocalyptic setting; moreover, the spatial confluence of this dystopia of eternally recurring natural disaster coupled with the resort culture's utopianism dramatizes the impossibility of fulfilling the utopian promise of liberation, not just from one's social role and biology but also from the natural world order--from all the physical elements that, according to their own laws, conspire either to give pleasure or to wash away humankind's hopes without a moment's notice. To recreate the resort culture's utopianism and to represent the islands as sites of romantic and temporal liberation, Chopin uses a longstanding convention of description that stretches back to Homer and Virgil called the locus amoenus trope. Meaning pleasant, lovely place in Latin, locus amoenus is an landscape (Curtius 195). Capable of constructing perfect, ideal spaces, the trope has the potential to represent the greatest possible utopian strivings of a culture. It is only natural then that Chopin would use it to depict the islands as the utopias her audience imagined them to be prior to the Hurricane of 1893. Yet while Chopin employs the trope to construct the islands, she also disrupts their utopian image by revealing an underlying presence of mortality and hostility in these island cultures. Her imagery subtly evokes the recurrence of the hurricane in the novel, partly through indirect allusions to the cultural rhetoric in newspapers reporting on the Hurricane of 1893, and with each of these storm events, she emphasizes the tremendous power the natural environment has over Edna's will, behavior, and embodiment. Ultimately, the hurricane's presence in the novel acts as a metaphor for the deterministic force of the natural environment and for all the forces that can determine our fates. Furthermore, the recurrence of this traumatic event leads to hopelessness, an overwhelming sense of the absolute futility of utopian strivings, that is amplified by the extreme disparity that exists between the Locus amoenus's representation of the ideal conditions in human life on the surface level of the narrative and the representation of a dystopia of recurring apocalypse on another level. …

Chemical flushing from an urban-fringe watershed: hydrologic and riparian soil dynamics

The goal of the current study is to better understand the role of storm dynamics on stream water chemical variability in a highly polluted urban-fringe watershed. The study was conducted in the upper reach of the Arroyo Seco watershed located on the eastern edge of the densely urbanized Los Angeles basin in California. During the 2008–2009 study period, high-frequency stream water observations of chloride, fluoride, sulfate, and nitrate were monitored through a series of storm events and were compared to pre- and post-winter storm season geochemical soil profiles. Of the four solutes measured, nitrate demonstrated hydrologically enhanced behavior. Chloride, fluoride, and sulfate exhibited enhanced behavior initially (first flush), but transitioned to dilution behavior as the season progressed. Soil chemistry analyses in the riparian zone confirmed the abundance of nitrate on the soil surface, serving as a source for stream water nitrate. Observations and analyses collectively suggest that the chemical variability observed during the storms is dependent not only on discharge, but also on the magnitude and intensity of rainfall, the length of the antecedent dry period, and riparian soil composition. A further understanding of these factors will ultimately improve geochemical models for prediction of downstream chemical loads from regional urban-fringe watersheds.

Edge Wave Scattering by Coastal Structures on Arbitrary Bathymetry

Abstract The formation of rhythmic patterns at the Field Research Facility (U.S. Army Corps of Engineers, Duck, North Carolina) under extreme wave climatic conditions is analyzed in terms of the partial standing oscillations formed by the superposition of the incident edge wave and the wave reflected by the structure. The reflection coefficient at the pier is evaluated with an existing model used for the propagation of an edge wave through a permeable structure perpendicular to the coastline, modified here to deal with an arbitrary beach profile. The mass transport patterns under the partial standing edge waves are found to resemble the beach cusps and the crescentic bars observed on the shore, north of the pier, after a series of storm events.

Storm travel distance calculations for total phosphorus and suspended materials in rivers

From previous work it appears that total phosphorus is transported through rivers by a series of storm events. This paper presents a method for calculating the average distance of travel during any given storm event. The method uses the hydrograph, chemograph, and flow characteristics at a point in the river. Comparisons were made between storm events at the same station in a river, between different stations in the same river basin, and between stations in different rivers. Results show the distance of travel is dependent upon the magnitude and duration of the storm event but not on the magnitude of the total phosphorus concentration.