2 Dec 2024

Comparison of Run-Up Models with Field Data

Abstract: Run-up predictions are inherently uncertain, owing to ambiguities in phase-averaged models and inherent complexities of surf and swash-zone hydrodynamics. As a result, different approaches, ranging from simple algebraic expressions to computationally intensive phase-resolving models, have been used in attempt to capture the most relevant run-up processes. Studies quantifiably comparing these methods in terms of physical accuracy and computational speed are needed as new observation technologies and models become available. The current study tests the capability of the new swash formulation of the Coastal Modeling System (CMS) to predict 1D run-up statistics (R2%) collected during an energetic 3 week period on sandy dune-backed beach in Duck, North Carolina. The accuracy and speed of the debut CMS swash formulation is compared with one algebraic model and three other numerical models. Of the four tested numerical models, the CSHORE model computed the results fastest, and the CMS model results had the greatest accuracy. All four numerical models, including XBeach in surfbeat and nonhydrostatic modes, yielded half the error of the algebraic model tested. These findings present an encouraging advancement for phase-averaged coastal models, a critical step towards rapid prediction for near-time deterministic or long-term stochastic guidance.

12 Sep 2024

Coherent Marine X-Band Radar Deployment during DUNEX

Abstract: A marine X-band radar system, developed by Helmholtz-Zentrum Hereon (Hereon) was deployed within view of the nearshore at the US Army Engineer Research and Development Center, Field Research Facility (FRF), in Duck, North Carolina, from October 2021 to August 2022. The radar deployment was a collaboration among researchers at the FRF, Hereon, and the University of Miami and was initiated as part of the During Nearshore Event Experiment (DUNEX), a large multi-institutional field experiment funded by the US Coastal Research Program. The Hereon radar successfully collected data during the main DUNEX field campaign (approximately October 2021) and continued to collect nearly continuously until August 2022. To facilitate use of Hereon radar data, this document describes the deployment, provides background and context, and presents metadata. Within, we describe in detail the Hereon radar system, the locations of two different installations, the time periods covered, sampling modes, environmental conditions and notable events, example data products, and potential pathways for future use of the data.

11 Sep 2024

Evaluating Topographic Reconstruction Accuracy of Planet Lab’s Stereo Satellite Imagery

Abstract: The goal of this Coastal and Hydraulics Engineering Technical Note (CHETN) is to document initial results to derive topography on the beachface in the northern Outer Banks, North Carolina, utilizing Planet Labs’ SkySat stereo panchromatic imagery processed in Agisoft Metashape. This technical note will provide an initial evaluation into whether Planet Lab’s SkySat imagery is a suitable image source for satellite Structure from Motion (SfM) algorithms as well as whether these data should be explored as a federal beach project monitoring tool. Depending on required accuracy, these data have the potential to aid coastal scientists, managers, and US Army Corps of Engineers (USACE) engineers in understanding the now-state of their coastlines and employ cost-effective adaptive management techniques.

5 Aug 2024

Analysis of Beach Cusp Formation and Evolution Using High-Frequency 3D Lidar Scans

Abstract: Beach cusp characteristics were explored using 15 months of 3D lidar scans collected hourly at the Duck, NC, Field Research Facility. Fourier analyses performed on lidar-derived beach elevation contours generated spatial cusp spectra. Active cusp events identified from the location and magnitude of each spectrum’s peak were used to evaluate conditions during cusp formation and evolution. Cusps primarily developed during normally-incident, long-period, low-energy wave conditions with low frequency spread and reflective beach conditions. Often, however, persistent upper-beach cusps lasted days to months and dynamic lower-beach cusps evolved over individual tidal cycles. At times, beaches exhibiting multiple cusp systems reverted to a single cusp system extending the entire beach when the high-tide waterline reached the upper-beach cusps, with the location and spacing of the resulting lower-beach cusps controlled by the upper-beach cusps. This is consistent with a “morphological coupling” hypothesis that hydrodynamic-morphodynamic feedbacks between the swash and upper-beach cusps can form lower-beach cusps with a related wavelength as the tide falls. However, sometimes the high-tide waterline reaching the upper-beach cusps did not result in a unified beach state. This suggest that morphological coupling is often an important factor in controlling the development of new lower-beach cusps but cannot initiate cusp formation in hydrodynamic conditions outside those favorable for cusp activity.

14 Jun 2024

Application of Coastal Resilience Metrics at Panama City Beach, Florida

Abstract: This study, for the first time, combines the Coastal Engineering Resilience Index (CERI) and Buffer Width (BW) metrics to better understand the historic, current, and future resilience of the coastal system at Panama City Beach, Florida. After the construction of the US Army Corps of Engineers Coastal Storm Risk Management (CSRM) project at Panama City Beach, the CERI resilience metric has increased up to 21.3%, while negative storm impacts in the same have been less than 8%. The frequency of nourishment efforts moving forward is justified by a 24.3% increase in the BW metric when comparing cases that are nourished frequently with cases that are not nourished frequently. Moreover, there is a 129.2% increase in the BW metric when comparing the frequently nourished cases with the cases that are nourished only on an emergency basis. While the CERI and BW metrics have both been considered previously, their combined application provides an understanding of a broader temporal view of how storm events, CSRM projects, and nourishments have played a part in the resilience of the system at Panama City Beach over the last two decades and how they may play a role in the next half century.

21 May 2024

Engineering With Nature: An Atlas, Volume 3

Abstract: Engineering With Nature: An Atlas, Volume 3 showcases EWN principles and practices “in action” through 58 projects from around the world. These exemplary projects demonstrate what it means to partner with nature to deliver engineering solutions with triple-win benefits. The collection of projects included were developed and constructed by a large number of government, private sector, nongovernmental organizations, and other organizations. Through the use of photographs and narrative descriptions, the EWN Atlas was developed to inspire interested readers and practitioners with the potential to engineer with nature.

4 Oct 2023

Full-Scale Trafficability Testing of Prototype Submersible Matting Systems

Abstract: This report describes the full-scale evaluation of prototype submersible matting systems (SUBMAT) at a test site at the US Army Engineer Research and Development Center’s Vicksburg, Mississippi, site. The SUBMAT prototypes were designed to bridge the gap between high and low tide at a beach interface to enable 24-hour operation at an expeditionary watercraft landing site. This phase of the SUBMAT prototype development was intended to determine prototype system durability by applying military vehicle loads representing a combat brigade insertion across a littoral zone. The two mat systems evaluated in this study were the PYRACELL Road Building System (PRBS) and a basaltic rebar mat system. The results of the study showed that the PRBS system was able to sustain 1,000 Medium Tactical Vehicle Replacement, 350 Heavy Expanded Mobility Tactical Truck, and over 150 M1A1 main battle tank passes without significant damage. The basaltic rebar mat failed early in the test and was removed from further consideration for the SUBMAT application. Observations and lessons learned from this phase of the prototype PRBS development will be used to improve the PRBS design and modify its installation procedures for improved efficiency.

11 Sep 2023

The Use of Native Vegetation and Natural Materials in Shoreline Stabilization: A Case Study of Bubble Gum Beach, Rehoboth Beach, Delaware

PURPOSE: This technical note is the fourth in a series about using native plant communities to achieve engineering and ecological purposes such as shoreline stabilization, structural enhancements, habitat creation, and ecosystem development. In this series, we demonstrate the utility of natural materials (specifically, native vegetation, oyster reefs, and coir logs) in living shoreline projects. Plant species and plant communities play critical roles in wave attenuation and sediment accretion in coastal areas. The application of vegetation in the coastal areas, especially on the East and Gulf Coasts, has focused heavily on the creation of living shorelines—serving both environmental and engineering purposes. This technical note documents the workshop conducted by the US Army Engineering Research and Development Center (ERDC) and hosted by the US Army Corps of Engineers’ (USACE) Philadelphia District (NAP) and Center for the Inland Bays. The goals of this technical note are (1) to demonstrate the application of native plant communities, oyster shells, and coir (coconut) materials and their installation techniques along shorelines to the engineering community; (2) to demonstrate how targeted vegetation establishment can facilitate ecosystem development along shorelines to improve engineering and environmental outcomes; and (3) to provide native vegetation installation techniques for living shorelines projects’ purposes.

8 Mar 2023

A Large-Scale Community Storm Processes Field Experiment: The During Nearshore Event Experiment (DUNEX) Overview Reference Report

Abstract: The DUring Nearshore Event EXperiment (DUNEX) was a series of large-scale nearshore coastal field experiments focused on during-storm, nearshore coastal processes. The experiments were conducted on the North Carolina coast by a multidisciplinary group of over 30 research scientists from 2019 to 2021. The overarching goal of DUNEX was to collaboratively gather information to improve understanding of the interactions of coastal water levels, waves, and flows, beach and dune evolution, soil behavior, vegetation, and groundwater during major coastal storms that affect infrastructure, habitats, and communities. In the short term, these high-quality field measurements will lead to better understanding of during-storm processes, impacts and post-storm recovery and will enhance US academic coastal research programs. Longer-term, DUNEX data and outcomes will improve understanding and prediction of extreme event physical processes and impacts, validate coastal processes numerical models, and improve coastal resilience strategies and communication methods for coastal communities impacted by storms. This report focuses on the planning and preparation required to conduct a large-scale field experiment, the collaboration amongst researchers, and lessons learned. The value of a large-scale experiment focused on storm processes and impacts begins with the scientific gains from the data collected, which will be available and used for decades to come.

13 Oct 2021

Engineering With Nature®: Supporting Mission Resilience and Infrastructure Value at Department of Defense Installations

Abstract: This book illustrates some of the current challenges and hazards experienced by military installations, and the content highlights activities at seven military installations to achieve increased resilience through natural infrastructure.