The comparison of two parametric wind models for hurricane storm surge prediction

The tropical storm surge models depend critically on the maximum surface wind and shape of the wind profile. Since none of them are easy to measure, designing the parametric wind models for the storm surge prediction becomes divergent. Two widely used, but very different, wind models are examined. The study of their parameters showed that their resulting maximum wind and the shape of the wind profiles are similar. This property is a very useful guide for evaluating different surge models.

Hurricane Flood Hazard Assessment for the Archipelago of San Andres, Providencia and Santa Catalina, Colombia

Despite the low occurrence of tropical cyclones at the archipelago of San Andres, Providencia, and Santa Catalina (Colombia), Hurricane Iota in 2020 made evident the area vulnerability to tropical cyclones as major hazards by obliterating 56.4 % of housing, partially destroying the remaining houses in Providencia. We investigated the hurricane storm surge inundation in the archipelago by forcing hydrodynamic models with synthetic tropical cyclones and hypothetical hurricanes. The storm surge from synthetic events allowed identifying the strongest surges using the probability distribution, enabling the generation of hurricane storm surge flood maps for 100 and 500 year return periods. This analysis suggested that the east of San Andres and Providencia are the more likely areas to be flooded from hurricanes storm surges. The hypothetical events were used to force the hydrodynamic model to create worst-case flood scenario maps, useful for contingency and development planning. Additionally, Hurricane Iota flood levels were calculated using 2D and 1D models. The 2D model included storm surge (SS), SS with astronomical tides (AT), and SS with AT and wave setup (WS), resulting in a total flooded area (percentage related to Providencia’s total area) of 67.05 ha (3.25 %), 65.23 ha (3.16 %), and 76.68 ha (3.68%), respectively. While Hurricane Iota occurred during low tide, the WS contributed 14.93 % (11.45 ha) of the total flooded area in Providencia. The 1D approximation showed that during the storm peak in the eastern of the island, the contribution of AT, SS, and wave runup to the maximum sea water level was −3.01%, 46.36%, and 56.55 %, respectively. This finding provides evidence of the water level underestimation in insular environments when modeling SS without wave contributions. The maximum SS derived from Iota was 1.25 m at the east of Providencia, which according to this study has an associated return period of 3,234 years. The methodology proposed in this study can be applied to other coastal zones and may include the effect of climate change on hurricane storm surges and sea-level rise. Results from this study are useful for emergency managers, government, coastal communities, and policymakers as civil protection measures.

ADVANCES IN THE UNSTRUCTURED WAVEWATCH III AND APPLICATION TO HURRICANE DORIAN

The spectral wave generation and propagation model WAVEWATCH III (WW3) is undergoing rapid development to extend capability and applicability. An option for unstructured grids and implicit solution provides WW3 with the flexibility and efficiency to resolve complex shorelines and high-gradient wave zones to drive nearshore circulation, wave setup, and wave-driven sediment transport with multi-scale spatial coverage over approximately three orders of magnitude. The model is compatible with community-based coupling infrastructure to facilitate two-way coupling with circulation models for simulating hurricane storm surge and waves. Unstructured WW3 is applied for 2019 Hurricane Dorian and validated with National Data Buoy Center buoys and nearshore gauges at the US Army Corps of Engineers Field Research Facility.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/kz9G46xUD0k

Growth Machine Up-links and the Manufacture of Flood Risk in Mid-twentieth Century New Orleans

Environmentally destructive megaprojects, which substantially shift the topography and hydrology of the ecosystems in which they are embedded in ways that potentially exacerbate preexisting disaster risks, are created through a combination of lobbying by municipal growth machines and applications of higher level state authority, resources, and control. New Orleans’ manufactured hurricane storm surge risk provides a crucial case study of this dynamic. After Hurricane Katrina, forensic engineers found that the proximate cause of the New Orleans flood was the levee and floodwall failures along the city’s shipping and drainage canals, but this disaster cannot be fully understood without an examination of the city’s mid-twentieth century political economy, particular regarding the power of the local shipping industry and its up-links to entities in the federal government. During this time period, local New Orleans elites were able to take advantage of the two world wars and postwar economic expansion to dramatically enlarge the city’s shipping canal system with massive funding and expertise from the Maritime Commission and the Corps of Engineers, massively amplifying the city’s flood risk in ways that ultimately led to the Katrina catastrophe.

The Utilization of Regression and Analysis of Variance to Model Hurricane Storm Surge Sedimentation on Coastal Marshes along the Northern Gulf of Mexico Coastline

<p>Coastal marshes along the northern Gulf of Mexico coastline provide very important ecosystem services such as serving as habitat for a variety of flora and fauna and providing flood protection for inland areas. A growing body of research has documented how hurricane storm surge sedimentation has increased the elevation of coastal marshes along the northern Gulf of Mexico coastline. This study investigates spatial variations in sediment distribution on McFaddin National Wildlife Refuge, Texas, USA, which is in the geographic region that was impacted by the right-front quadrant of Hurricane Ike. This research builds upon a prior study on hurricane storm surge sedimentation in which the sediment deposits from hurricanes’ Audrey, Carla, Rita, and Ike were identified on a marsh transect on McFaddin National Wildlife Refuge. The purpose of this study was to discover how hurricane storm surge sedimentation spatially varies in relation to the landfall location of Hurricane Ike. Fieldwork conducted in 2017-2018 involved digging shallow pits on four coastal marsh transects between Sabine Pass, Texas and High Island, Texas. Elevations were measured at each pit site along all four transects using a telescopic lens and stadia rod. The transects extend 880-1630 meters, with pit sites beginning near the coastline and extending landward. Results obtained in the field indicate that the Hurricane Ike sediment deposit has been found on all four transects, and that the deposit decreases in thickness moving landward along each transect. Furthermore, the observational results of this study were used in Regression Analyses to model hurricane storm surge sediment deposit thickness based on pit site distance inland, pit site elevation, and distance from the landfall of Hurricane Ike. Moreover, Analysis of Variance revealed whether distance inland, distance from landfall location, and the interaction between distance inland and distance from landfall location had any significant effect on storm surge deposit thickness. Actual sediment deposit thicknesses measured in the field were compared to the Regression and Analysis of Variance results. Results show that the Power Law Curve from the Regression Analyses was the most robust predictor of pit site sediment thickness based on distance inland, with an R<sup>2</sup> value of 0.538. Additionally, the Regression and Analysis of Variance results revealed that transect distance from the landfall location of Hurricane Ike was the only independent variable that could not predict or explain storm surge deposit thickness; which is very likely due to all four transects being in the right-front quadrant of landfalling Hurricane Ike. The findings of this study provide improved understanding of the spatial relationship between storm surge sedimentation and storm surge heights, valuable knowledge about the sedimentary response of coastal marshes subject to storm surge deposition, and useful guidance to public policy aimed at combating the effects of sea-level rise on coastal marshes along the northern Gulf of Mexico coastline.</p><p> </p>