17 Jul 2026

Application of GPS/GSM (Global System for Mobile Communications) Tag Technology to Investigate Seasonal Habitat Use by a Coastal Bird: A Pilot Study Using the Royal Tern (Thalasseus maximus)

Purpose: This technical note was developed by personnel from the US Army Engineer Research and Development Center–Environmental Laboratory (ERDC-EL) to describe the application of GPS/GSM (Global System for Mobile Communications) technology to wildlife studies to assess the effects of coastal engineering operations. GPS/GSM tags utilize cell tower transmissions to accurately locate animal positions in the landscape. While some satellite-based wildlife tags use Doppler technology, the GPS/GSM tags rely on GPS-based technology, which improves level position accuracy (e.g., ±30 m GPS/GSM tags versus ±300 m Doppler tags) in the landscape.* Doppler satellite tags break down distance accuracy into six location categories that range from ≤150 m to over 1,000 m, with a general average location accuracy of ≥300 m. The level of position accuracy with GPS/GSM tag technology permits researchers to determine if tagged birds are utilizing recently engineered coastal habitats (e.g., renourished beaches, dredged material islands, and restored wetlands), natural habitats, or minimally engineered coastal habitats. GPS/GSM tags could also be used to assess the frequency and seasonal changes of habitat use. Many coastal birds are known to breed on coastal dredged-material islands, often in response to coastal habitat loss wrought by dredging operations and other engineering actions (Soots and Landin 1978). In these same coastal areas, habitat degradation can occur through increased erosion and increased storm frequency and severity. The resulting habitat loss contributes to observed declines in coastal bird populations (Iglecia and Winn 2021; Newton 2004). These long-term population declines are not solely affecting coastal breeding species (Rosenberg et al. 2016). Habitat loss and population declines are also affecting many long-distance migrants that are seasonally transient and, thus, found along coastal habitats of the conterminous United States (Winn et al. 2013). The federally threatened Red Knot (Calidris canutus) is an example of a coastal transient species. Numerous other coastal birds currently experiencing population declines are potential candidates for future federal listing (Winn et al. 2013; Iglecia and Winn 2021). Interestingly, survey data suggested the Snowy Plover (Charadrius nivosus) avoids beaches that have been subjected to renourishment (Lott 2009; Lott and Fischer 2011), indicating that there may be variable, species-specific seasonal responses to coastal engineered habitats that remain poorly understood for many coastal birds. Therefore, there is a growing interest in determining the seasonal habitat needs of resident and migrant coastal birds and in approaches to beneficial uses of dredged material (BUDM) that could be used to design and construct year-round habitats (Guilfoyle et al. 2019, 2024).* However, much more research is required to determine the basic ecology, seasonal distribution, and seasonal habitat requirements of North American coastal birds to facilitate improved coastal habitat restoration and conservation. This technical note describes a pilot study in which 10 GPS/GSM tags were affixed to breeding Royal Terns (Thalasseus maximus; Figure 1) captured on South Island of the Hampton Roads Bridge-Tunnel in coastal Virginia. This study was part of a larger project to compile best management practices (Guilfoyle et al. 2019) and suggested management strategies† and was funded through the Ecosystem Management and Restoration Research Program (EMRRP). The Royal Tern was selected for this effort due to its relatively large size, which was suitable for a GPS/GSM tag, its known dependence on dredged-material islands for breeding, and its use of open beach habitats in the Southeastern United States and along the Gulf Coast during the wintering season.

13 May 2026

Beach-fx Version 3.0 User’s Manual

Abstract: The need to strengthen the linkages between engineering analyses (project performance and evolution) and planning functions (alternative analysis and economic justification) with respect to coastal storm damage reduction projects within the US Army Corps of Engineers led to the development of the life-cycle simulation model Beach-fx. Beach-fx provides a comprehensive analytical framework for evaluating the physical performance and economic benefits and costs of shore protection projects, particularly beach nourishment along sandy shores. The model has been implemented as an event-based Monte Carlo life-cycle simulation tool that is run on desktop computers. This report describes the components, purpose, and operational function of the Beach-fx graphical user interface, including navigation within the interface and the organization and specification of all model input and output data.

9 Feb 2026

Ice-Resistant Breakwater Rock Sizing at Elim, Alaska

Abstract: The Elim Subsistence Harbor project requires breakwaters capable of withstanding wave action and sea ice forces in Norton Bay, Alaska. This study analyzed meteorological data, satellite imagery, and ice formation patterns to determine appropriate armor stone sizing based on ice forces for the proposed breakwaters. Analysis revealed that Elim experiences predominantly northerly winds during winter, with southwesterly components developing during the May–June breakup period. Offshore ice breakup occurs earlier at Elim (late March) than at Nome (late April). Using the Modified Stefan Equation calibrated with field measurements, end-of-season ice thickness near shore averages 1.4 m. Ice forces at Elim are expected to be less severe than at Nome because of wind patterns and directional constraints, with primary concerns limited to ice approaching from southwest directions during breakup. Using empirical evidence from Nome Harbor and physical model studies, we recommend a zoned armoring approach using 8-ton stone for toes and 4-ton stone on slopes in ice-exposed areas as minimum protection, or 8-ton stone throughout ice-exposed zones for enhanced durability. Relatively steep slopes (1.5H:1V to 2H:1V) should be maintained to encourage protective rubble ramp development during ice interactions.

10 Dec 2025

A Qualitative Comparison Review Between Commonly Used Boussinesq Models

Abstract: The purpose of this Coastal and Hydraulics Engineering Technical Note (CHETN) is to summarize the Boussinesq models FUNWAVE, Coulwave, and Celeris. This CHETN outlines the governing equations and numerical schemes for each model and presents the order of their error terms. A qualitative comparison was completed between the fully nonlinear models, FUNWAVE and Coulwave, and the weakly nonlinear model, Celeris. Results from this comparison demonstrate capabilities for each model by comparing previously published benchmark validation cases. The discussion section highlights additional areas of research and report recommendations.

4 Apr 2025

Living Shoreline in USACE Projects: A Review

Abstract: The term living shoreline (LS) refers to the practice of shoreline stabilization using natural elements (e.g., vegetation, oysters, logs, etc.) in a way that maintains continuity and connectivity between terrestrial and aquatic habitats. This report provides a review of LS practices to assess the applicability of these engineering techniques for US Army Corps of Engineers (USACE) projects. Specifically, this review examines the current state of knowledge regarding LS efforts through evaluation of peer-reviewed literature, agency reports, web tools, applications, and relevant guidance. It is important to gain a deeper understanding of the potential ecological, engineering, environmental, and socioeconomic benefits in comparison with traditional gray infrastructure shoreline stabilization techniques. The National Oceanic and Atmospheric Administration (NOAA) encourages the use of LS as a shoreline stabilization technique along sheltered coasts (i.e., coasts not exposed to open ocean wave energy) to preserve and improve habitats and maintain their ecosystem services at the land–water interface. Research has examined aspects of LSs, but there are relevant knowledge gaps yet to be explored. Overall, there is a lot of information from different sources on LSs with limited application to USACE projects. Therefore, a consolidated planning and design consideration report specific to USACE is recommended.

26 Aug 2024

FUNWAVE-TVD Testbed: Analytical, Laboratory, and Field Cases for Validation and Verification of the Phase-Resolving Nearshore Boussinesq-Type Numerical Wave Model

Abstract: Over the last couple of decades, advancements in high-performance computing have allowed phase-resolving, Boussinesq-type numerical wave models to be more practical in addressing nearshore coastal wave processes. As such, the open-source FUNWAVE-TVD numerical wave model has become more ubiquitous across all scientific and engineering-focused R&D organizations, including academic, government, and industry partners. In collaboration with the US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory; the University of Delaware; and HR Wallingford, a robust testbed has been developed to allow users to benchmark their applications against new releases of the model. The testbed presented here includes analytical, laboratory, and field cases, to provide guidance on the operational utility of FUNWAVE-TVD and examines numerical convergence, accuracy, and performance in modeling wave generation, propagation, wave breaking, and moving shorelines in nearshore wind-wave applications. A brief discussion on the efficiency of the model across parallel computing platforms is also provided.

29 Jul 2024

Rectifying and Stabilizing Planet SkySat Video Collects for Bathymetric Inversions from Space

Abstract: This Coastal and Hydraulics Engineering Technical Note (CHETN) presents the development of a workflow to process Planet SkySat videos collected from space at the US Army Engineer Research and Development Center (ERDC), Coastal and Hydraulics Laboratory (CHL), Field Research Facility (FRF), in Duck, North Carolina, to derive wave kinematics and perform bathymetric inversions. The document summarizes the nine 30–60 s* satellite video collections, demonstrates the accuracy of an automated rectification and stabilization workflow, and applies a new short-dwell version of a common inversion algorithm (cBathy) to demonstrate the utility of short-dwell videos from space providing an initial out-of-the-box assessment of errors for one of the collections, and recommends future avenues of research for improving bathymetric predictions.

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.

8 Apr 2024

Coastal Modeling System User’s Manual

Abstract: The Coastal Modeling System (CMS) is a suite of coupled 2D numerical models for simulating nearshore waves, currents, water levels, sediment transport, morphology change, and salinity and temperature. Developed by the Coastal Inlets Research Program of the US Army Corps of Engineers, the CMS provides coastal engineers and scientists a PC-based, easy-to-use, accurate, and efficient tool for understanding of coastal processes and for designing and managing of coastal inlets research, navigation projects, and sediment exchange between inlets and adjacent beaches. The present technical report acts as a user guide for the CMS, which contains comprehensive information on model theory, model setup, and model features. The detailed descriptions include creation of a new project, configuration of model grid, various types of boundary conditions, representation of coastal structures, numerical methods, and coupled simulations of waves, hydrodynamics, and sediment transport. Pre- and postmodel data processing and CMS modeling procedures are also described through operation within a graphic user interface—the Surface Water Modeling System.

3 Oct 2022

Practical Guidance for Numerical Modeling in FUNWAVE-TVD

Purpose: This technical note describes the physical and numerical considerations for developing an idealized numerical wave-structure interaction modeling study using the fully nonlinear, phase-resolving Boussinesq-type wave model, FUNWAVE-TVD (Shi et al. 2012). The focus of the study is on the range of validity of input wave characteristics and the appropriate numerical domain properties when inserting partially submerged, impermeable (i.e., fully reflective) coastal structures in the domain. These structures include typical designs for breakwaters, groins, jetties, dikes, and levees. In addition to presenting general numerical modeling best practices for FUNWAVE-TVD, the influence of nonlinear wave-wave interactions on regular wave propagation in the numerical domain is discussed. The scope of coastal structures considered in this document is restricted to a single partially submerged, impermeable breakwater, but the setup and the results can be extended to other similar structures without a loss of generality. The intended audience for these materials is novice to intermediate users of the FUNWAVE-TVD wave model, specifically those seeking to implement coastal structures in a numerical domain or to investigate basic wave-structure interaction responses in a surrogate model prior to considering a full-fledged 3-D Navier-Stokes Computational Fluid Dynamics (CFD) model. From this document, users will gain a fundamental understanding of practical modeling guidelines that will flatten the learning curve of the model and enhance the final product of a wave modeling study. Providing coastal planners and engineers with ease of model access and usability guidance will facilitate rapid screening of design alternatives for efficient and effective decision-making under environmental uncertainty.