30 Jan 2026

Linear Propagation of Tsunami and Acoustic–Gravity Waves on a Sphere: Geometrical Focusing and Defocusing

Abstract: This study investigates the propagation of tsunami and acoustic–gravity waves at oceanic scales, accounting for the Earth’s curvature within a linear, potential flow framework. While local, near-field analyses often neglect Earth’s curvature and employ Cartesian or cylindrical coordinate systems, this work utilises spherical coordinates to examine wave behaviour over large distances. The analysis reveals that wave amplitudes experience a defocusing effect as they travel from the source (e.g., the Pole) toward the equator, followed by a focusing effect as they approach the antipodal point beyond the equator. A qualitative comparison is made with the 2022 Hunga Tonga–Hunga Ha’apai volcanic eruption in the South Pacific. The study models surface-gravity (tsunami) waves propagating through a compressible water layer, as well as atmospheric acoustic–gravity waves propagating through the air. The entire analysis is carried out within the framework of linear theory.

29 Jan 2026

A Monolithically Coupled Surface Water and Groundwater Finite Element Model with Fully Implicit Time Stepping Using Adaptive Hydraulics (AdH) v5.0 (KraRE: 21428 (ken)

Abstract: Simulation of surface water and groundwater interaction is becoming increasingly important for the US Army Corps of Engineer Civil Works and Military Missions. This report details the formulation of a monolithic, coupled approach that combines the Richards equation for variably saturated groundwater flow and a diffusive wave approximation for overland flow. The model is implemented with USACE’s Adaptive Hydraulics (AdH) computational framework and is evaluated for several community benchmark problems. The results indicate that the AdH model is stable with performance similar to existing, well-established codes for surface water and groundwater interaction.

21 Jan 2026

Development of Tidal and Surge Forcing in Boussinesq Wave Model FUNWAVE-TVD

PURPOSE: This Coastal and Hydraulics Engineering Technical Note (CHETN) documents the development of the tidal and surge-forcing module in the Boussinesq wave model FUNWAVE–Total Variation Diminishing (TVD) for wind-wave simulations, subjected to large-scale boundary forcing conditions. In a series of recent projects undertaken by the Coastal Hydraulics Laboratory (CHL) of the US Army Engineer Research and Development Center (ERDC), there was a need to model wind waves under time-varying boundary conditions due to tides, storm surges, or strong background flows. The implications on wave runup and overtopping (flooding) around inlets, due to the interaction of tide or surge-driven flows and waves (wave-current interactions), make the need for the development of surge and tide forcing vital to modeling waves with a Boussinesq-type model like FUNWAVE-TVD. Furthermore, strong velocity flows (currents) are not only responsible for depth-limited wave transformation and breaking at inlets but also directly influence sediment transport. Most phase-resolving wave models cannot facilitate these kinds of simulations because the wavemaker cannot generate the phase-resolving wave conditions and low-frequency motions (e.g., tides) at the same time. For example, in FUNWAVE-TVD, the combination of an internal wavemaker and a sponge layer is used to generate wind waves in the shoreward direction while absorbing waves with the sponge layer in the seaward direction behind the wavemaker. However, this type of combined system of wave generation and absorption cannot readily incorporate the external low-frequency forcing into wave generation.

13 Jan 2026

Wave Information Study ERA5 Wind-Field Evaluation

Abstract: The Wave Information Study (WIS) provides continuous wave hindcasts along US coastlines, including the Great Lakes and US Territories. As wave modeling and wind-field technologies have advanced, WIS is now positioned to transition to the new long-term archived hindcast wind fields available from ERA5, the fifth-generation global atmospheric reanalysis from the European Centre for Medium-Range Weather Forecasts. Before adopting ERA5 operationally within the WIS hindcast, formal testing compared ERA5 wind-forced hindcasts to the existing WIS hindcasts using Nation Center for Atmospheric Research Reanalysis 1 (NCAR-R1) winds. Results were validated against collocated and concurrent point-source and altimeter-based wave measurements from 2015 to 2018. ERA5 showed a 53% improvement in significant wave-height bias in the Atlantic and 76%–77% improvements in the Pacific. While improvements in average wave period were less consistent, ERA5 still showed better correlation across all domains. Hawaii showed modest improvements, except for bias. ERA5 also outperformed NCAR-R1 in mean wave direction at peak frequency, with bias reductions of 5%–72%, most notably in Hawaii, where wave modeling is typically challenging. Overall, it was concluded that the ERA5 forced WIS estimates were more accurate than the NCAR forced WIS estimates, supporting the operational transition of WIS to ERA5.

13 Jan 2026

Major Freight Corridors in the US: Mapping of Commodity Flows on Waterborne, Rail, and Truck Networks

Abstract: Within the context of complex, interconnected, multimodal transportation, the US Army Corps of Engineers (USACE) provides safe, reliable, efficient, effective, and environmentally sustainable waterborne transportation systems for the movement of commerce, national security needs, and recreation. Understanding the role of waterways within the multimodal transportation system would allow for comprehensive resource allocation, including dredging prioritization. In 2022, approximately 19,810 million tons of goods were transported within, to, and from the US, with truck being the dominant mode for the domestic portion of the trip (64 percent). Relatively recent legislation calls for a multimodal representation of freight, one that facilitates transportation planning and asset management. However, traditional data collection and analysis has focused on single modes, preventing nationwide, multimodal representations of commodity flows. This report presents major commodity corridors within, to, and from the US by combining diverse sources and homogenizing data dimensions. The resulting information and commodity-specific maps help to contextualize waterborne navigation’s role within the broader multimodal transportation system. A key finding from the study indicates that the mouth of the Mississippi River in Louisiana carried in 2019 more volume of freight annually than any other waterway, railroad, or highway segment in the US.

9 Jan 2026

Design of River Training Structures Using Isogeomorphic Constraints

Abstract: Prepared for the Mississippi River Geomorphology and Potamology program of the United States Army Corps of Engineers (USACE), through the Coastal and Hydraulics Laboratory (CHL), this report introduces the concept of river control structure design using isogeomorphic constraints. The report defines isogeomorphic design methodology and demonstrates the application of the methodology using both analytic and numerical examples. The examples investigated herein are idealized, and application to real-world conditions (such as a dike-field) would be far more complex than what is demonstrated herein. This report merely serves as an introduction to a novel design paradigm that future studies can further investigate and refine with the ultimate objective of developing improved design guidance for USACE.

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.

10 Dec 2025

Evaluation of Vegetated Shoreline Capacity Using CSHORE-VEG

Abstract: A versatile vegetation module has been implemented into the Cross-Shore model (CSHORE) to evaluate the capacity of coastal and marine wetlands with respect to wave-height attenuation and wave-runup reduction. This extended model, Cross-Shore-Vegetation (CSHORE-VEG), is capable of simulating the effects of rigid and flexible vegetation with spatially varying biomechanical properties. To accurately estimate the vegetation-induced energy dissipation rate, a drag coefficient formula that is independent of the vegetation flexibility was developed based on field data collected in salt marshes in Terrebonne Bay, Louisiana, during a tropical storm. This universal drag coefficient formula along with other existing drag coefficient formulas have been implemented into CSHORE-VEG to meet different needs. CSHORE-VEG has been validated against four independent datasets involving different vegetation properties for wave attenuation and mean water level change. After achieving good agreement in model-data comparisons, CSHORE-VEG was employed to quantify the capacity of two representative salt marshes composed of Spartina alterniflora and Elymus athericus for wave attenuation. As a result, two ineffective vegetated shoreline scenarios were identified. Furthermore, a procedure for determining the percentage of broken vegetation stems and modeling the corresponding wave-height reduction was applied to evaluate the wave-height reduction under realistic field conditions.

10 Nov 2025

Spatial Analyses of Atmospheric Rivers in the Willamette River Basin of Oregon: Literature Review and Atmospheric River

Abstract: This technical note summarizes the literature review and atmospheric river (AR) detection technique data collection and initial processing activities that were performed in preparation to spatially storm type (i.e., categorize) AR extreme storm events in Oregon’s Willamette River Basin (WRB). Storm typing is performed to develop a homogeneous extreme event dataset for precipitation-frequency analyses, whose products are used to support business line (e.g., Dam and Levee Safety and Flood Risk Management) activities of the US Army Corps of Engineers (USACE). Twenty-three Atmospheric River Tracking Method Intercomparison Project (ARTMIP) Tier 1 data catalogs were collected from the US National Science Foundation’s National Center for Atmospheric Research Climate Data Gateway (Rutz et al. 2019). Each catalog models the binary presence or absence of an AR on a gridded basis, globally, at a three-hour time step from 1980 to 2016. Any ARTMIP Tier 1 catalog could effectively be selected and applied to segment AR extreme storm events for a given area by intersecting it with a prescribed precipitation dataset. However, each catalog characterizes the presence or absence of ARs differently. Hence, there exists uncertainty regarding which ARTMIP Tier 1 catalogs to select for a given practical application. This technical note addresses the uncertainty associated with ARTMIP Tier 1 catalog choice by generalizing model selection (i.e., which ARTMIP Tier 1 methods to use). Monthly climatological AR frequency was calculated throughout the WRB for each of the 23 ARTMIP Tier 1 data catalogs. Thirteen of the AR identification and tracking methods that together consistently calculated climatological AR frequency throughout the WRB were selected to form an ensemble subset. The 13-member ensemble could be used to develop AR storm type (Ralph et al. 2019) annual and seasonal maxima datasets to compute areal-precipitation-frequency estimates for the contributing drainage areas of dams in the WRB that are operated and maintained by USACE.

5 Nov 2025

Physical Modeling of Filling and Emptying (F&E) Systems of Proposed 1,200 ft Chambers at Locks 22 and 25: Hydraulic Model Investigation

Abstract: The US Army Corps of Engineers (USACE) is considering navigation improvements for several projects to meet predicted increases in tow traffic at the Lock and Dam 22 and Lock and Dam 25 sites in the Mississippi river. Some of these improvements include the addition or replacement of the navigation lock at the site. The following document contains the laboratory model investigations of the lock filling and emptying (F&E) system for additions at the sites. This report provides the results of research testing under the Navigation and Ecosystem Sustainability Program (NESP). The design guidance includes culvert geometry, port size, location, and spacing. Guidance for the lock chamber performance, based on acceptable filling and emptying operations is also included. The results show that the original design is a feasible design based on the hydraulic performance of the system as a result of the experimental tests. Further discussions with the St. Louis District (CEMVS) arrived at a new culvert to port transition design that was more in line with the existing geometry at Lock and Dam 25. The new design and port spacing configuration were agreed by CEMVS and ERDC to not have significant impact on hawser forces or the overall chamber performance.