16 Dec 2025

Procedures for Obtaining US Air Force Global Air-Land Weather Exploitation Model (GALWEM) Data for Hydrological Modeling Applications: An Overview of the GALWEM Acquisition System (GAS) v1.0 and v2.0

Abstract: The Global Air Land Weather Exploitation Model (GALWEM) Acquisition System (GAS) is a software platform that serves to automate and simplify the procurement of numerical weather prediction model data from the 557th Weather Squadron. GAS allows for the download of meteorological and other environmental parameters from the GALWEM, an operational Numerical Weather Prediction capability operated by the 557th Weather Squadron for use by both Air Force and Army interests. GAS provides the ability to archive GALWEM data so that it may be used by the US Army Engineer Research and Development Center (ERDC) and other researchers. The report describes multiple methodologies for data access as well as suggestions for future work to improve computational efficiency and customer access.

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.

8 Dec 2025

Assessing Fish-Passage Rates

Abstract: Riverine fragmentation by dams, culverts, and other barriers has led to the precipitous decline of migratory fishes nationwide. Accordingly, fish-passage restoration has emerged as a significant issue for resource agencies, restoration professionals, and fisheries managers. This special report addresses the key scientific challenge of measuring fish-passage rates before and after restoration. A variety of techniques for both forecasting (preproject) and monitoring (postproject) fish-passage rates are reviewed. A set of guiding questions are presented to help practitioners select a method appropriate to their site, resources, and time line. Four case studies are then presented to demonstrate a subset of these methods in practice: fish community movement through floodgate structures in Missouri, movement patterns through river restoration structures in Colorado, fish movement around a low-head weir in Mississippi, and watershed-wide passability estimation using professional judgment in Nevada. These projects represent a range of conditions and are intended to provide practitioners with real-world examples to use as models for their own studies.

8 Dec 2025

Modeling Tools for Proactive Ecosystem Restoration and Assisted Migration Planning: A State of the Science Review and Synthesis

Abstract: Decision-support modeling tools are needed to help aquatic ecosystem restoration (AER) planners understand how habitat footprints and species distributions will change in response to future changing conditions. Specifically, environmental projections and predictive model outputs that inform proactive AER planning and investments. This report provides a literature synthesis of resources and tools to create such a decision support tool. Select models identified were evaluated for applicability to AER planning using prediction confidence, user-friendliness, and suitability. This uncovered several existing, primarily terrestrially, predictive models that could be adapted to inform proactive AER planning efforts. Research efforts are still needed to fill gaps for aquatic data to train and validate predictive models, refine key drivers, and build and pilot aquatic-focused tools. Future condition vulnerability screening tools could be used to identify which proposed AER project sites are best suited for proactive AER measures, such as assisted migration, and determine if investments in more rigorous, spatially explicit, or species-specific models are needed. Species-specific assessments of habitat suitability changes and adaptive capacity can then inform restoration targets and enable end-users to achieve AER planning objectives. Such a decision support tool would improve planner ability to restore key aquatic habitats resilient to future conditions.

8 Dec 2025

Improved Prediction of Soil Thermal Properties Using Gated Recurrent Unit Neural Networks

Abstract: Frost actions, such as frost depth penetration and thaw weakening, are damaging to airfields and roadways in cold regions. Machine learning techniques, such as recurrent neural networks, have been applied to this problem, but with a large focus on long short term memory (LSTM) neurons. Gated recurrent units (GRUs) are similar to LSTM neurons in terms of accuracy, but are more computationally efficient, and have yet to be applied to predicting soil thermal properties. Using a hyperparameter search, an optimal architecture for a recurrent neural network based on gated recurrent units was identified. A general model using temperature, thermal conductivity, and volumetric moisture content was found to predict temperatures effectively, having an error of less than 0.25°F across all depths. For predicting thermal conductivity, a model including temperature but not moisture content was found to be effective. For moisture content, the results were inconclusive as both models were affected by similar errors. Overall, the GRU-base recurrent neural networks were found to work well for predicting soil thermal properties in high-plasticity clays, and it is recommended to further expand the training datasets to include other frost-affected soil types.

24 Nov 2025

Ice Demolition Techniques—Rapid Improved Ribbon Bridge Placement and Enemy Forces Denial: Using Traditional Military Explosives Under Ice

Abstract: As the United States military focuses on furthering their lethality across cold regions, developing new techniques for equipment usage is necessary. On 19 March 2025, the US Army Engineer Research and Development Center–Cold Regions Research and Engineering Laboratory (ERDC-CRREL) collaborated with the Army Engineers from the 50th Multi-Role Bridge Company (MRBC), 6th Brigade Engineer Battalion (BEB), and Sapper Leader Course (SLC) to determine whether explosives can be used for Improved Ribbon Bridge (IRB) placement in ice-laden environments. As the US Army adapts to meet the evolving threats from foreign adversaries, there is an increased tactical necessity for enhanced bridging capabilities in frozen terrain. Developing an expedient method of removing ice from these waterways and placing IRBs for easy crossing of heavy military equipment is essential. Through this experiment it was determined that the use of a 40 lb cratering charge primed with M152 boosters significantly fractures the ice cover expeditiously. However, the ice expulsion rate found in this experiment was insufficient for IRB deployment which requires 60% expulsion rate. Although the experiment fell short of IRB requirements, it proved to be an efficient and effective countermobility tool for units who use frozen water ways as avenues of approach.

24 Nov 2025

3D Printing Natural Materials for Nature-Inspired Infrastructure— A Beneficial Use Opportunity: Collaborative Research Workshop Synthesis

Abstract: Natural infrastructure—crucial for coastal resilience, flood risk management, and ecosystem services—confronts escalating challenges from rising seas, erosion, storms, and human impacts. Innovative approaches are needed to enhance infrastructure functionality and broaden social, economic, and environmental benefits. Traditional manufacturing constrains engineering creativity required for nature-inspired infrastructure (NII). Additive manufacturing, or 3D printing (3DP), could revolutionize the design and functionality of NII. However, existing capability gaps hinder the effective transition of these technologies from conceptualization to implementation. Our workshop explored NII-3DP structures using natural materials, aligning with Engineering With Nature® (EWN®) principles and US Army Corps of Engineers infrastructure goals. Discussion included engineering solutions to provide social, recreational, environmental, and economic benefits, including flood risk reduction, wave energy dissipation, nutrient sequestration, and habitat enhancement. The participants sought to understand material selection and optimize morphologies to ensure the successful biocompatibility of nature-based habitats. By using locally sourced, biocompatible materials and drawing inspiration from nature, these technologies offer a means to enhance habitat function and improve aesthetics for communities. A timely opportunity exists to reshape the perception of locally available materials, such as sediment, by presenting dredged material as an environmentally and economically beneficial use asset and resource for 3DP feedstocks.

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.