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.

4 Nov 2025

Preliminary Evaluation of Selected Expeditionary Shelter Systems in a Subarctic Environment: Phases I and II of Cold Weather Testing

Abstract: The warming of high latitude regions is causing geopolitical concerns and spurring increased human presence across the Arctic. Potentially, these situations require only a short-term occupation necessitating tested and developed expedient infrastructure. Operating requirements for high latitude conditions are vastly divergent from temperate locations. Shelters must be able to provide habitable conditions at temperature down to −60°F, withstand 100 mph wind speeds, and support 25 lb/ft2 of snow load. Although great advances have been made in providing efficient and comfortable Arctic infrastructure since the onset of the Cold War, significant work remains to further increase efficiencies and adapt to changing weather parameters. To address infrastructure technology gaps, the US Army Corps of Engineers–Engineering Research and Development Center (USACE-ERDC) established the Arctic Infrastructure Research Group (AIRG). Over two phases of investigation, the AIRG evaluated three selected expeditionary shelter systems at its Arctic Infrastructure Research Center (AIRC) in Fairbanks, Alaska during the winters of 2020–2021 (Phase I) and 2021–2022 (Phase II).

4 Nov 2025

High-Frequency Electromagnetic Induction for Oil Detection in Freshwater Ice Conditions

Abstract: High-frequency electromagnetic induction (HFEMI) effectively detects objects and materials in environments where visual detection may not be possible. Existing HFEMI sensor designs are for detection of improvised explosive devices and unexploded ordinances. This project applied this technology to oil spill detection and response applications. Because of the significant ice cover experienced in the Great Lakes Regions, the US Coast Guard requires fast and effective means to detect and characterize oil spills in and under layers of ice. HFEMI technology was adapted and evaluated for its ability to detect submerged oil of various types under several conditions of ice. The signal response of the sensor shows this technology is effective at detecting different types and volumes of oil in thin to moderate ice conditions, but could be improved to expand the distance of detection for thicker ice coverage.

4 Nov 2025

Airfield Assessments to Identify Improvements in Support of Arctic Military Operations: Arctic Airfields Assessment

Abstract: This report examines current airfield capabilities in Alaska and Greenland as they pertain to the strategic priorities of the Northern Aerospace Defense Command (NORAD) and US Northern Command (NORTHCOM) in support of needs identified in the 2024 DoD’s Arctic Strategy. With increasing activity and competition in the circumpolar region, airfields in Alaska and Greenland play a vital role in enabling homeland defense, supporting domain awareness needs, and enabling rapid response operations. This report highlights key airfields across Alaska and Greenland, focusing on their current readiness to support NORAD-assigned airframes such as the C-17, C-130, F-15, F-16, F-22, F-35A, KC-10, KC-135 and KC-46A. It assesses currently available infrastructure, operational resilience, airfield suitability and current condition, weather considerations, and logistics sustainment. Gaps in infrastructure readiness and logistical necessities for different airframes are identified. Recommendations are provided to bolster airfield operational capabilities as they pertain to the NORAD mission, and to ensure Arctic basing remains a credible enabler of NORTHCOM’s mission to defend the US and deter threats across the circumpolar region.

30 Oct 2025

Thermomechanical Material Characterization of Polyethylene Terephthalate Glycol Carbon Fiber 30% for Large-Format Additive Manufacturing of Polymer Structures

Abstract: Large-format additive manufacturing (LFAM) is used to print large-scale polymer structures. An understanding of the thermal and mechanical properties of polymers suitable for large-scale extrusion is needed for de-sign and production capabilities. An in-house-built LFAM printer was used to print polyethylene terephthalate glycol with 30% short carbon fiber (PETG CF30%) samples for thermomechanical characterization. Thermogravimetric analysis confirmed the samples had 30% carbon fiber by weight. X-ray microscopy and porosity studies found 25% porosity for undried material and 1.63% porosity for dry material. Differential scanning calorimetry showed a glass transition temperature (Tg) of 66°C, while dynamic mechanical analysis found Tg to be 82°C. The rheology indicated that PETG CF30% is a good printing material at 220°C–250°C. Bending experiments showed an average of 48.5 megapascals (MPa) for flexural strength, while tensile experiments found an average tensile strength of 25.0 MPa at room temperature. Comparison with the literature demonstrated that the 3D-printed PETG CF30% had a high Young’s modulus and was of similar tensile strength. For design purposes, prints from LFAM should be considered from a bead–layer–part standpoint. For testing purposes, both material choice and print parameters should be considered, especially when considering large layer heights.

30 Oct 2025

Full-Scale Evaluation of Multi-Axial, Multi-Aperture Shape Geogrids in Flexible Pavement Applications

Abstract: The US Army Engineer Research and Development Center (ERDC) con-structed a full-scale pavement test section to evaluate the performance of three recently developed multi-axial, multi-aperture shape geogrids, referred to as HX5.5, NX750, and NX-Dev, in asphalt-surfaced highway applications. The test section consisted of a 4.2 in. thick and a 3.8 in. thick hot-mix asphalt layer placed over a 6 in. thick and 4 in. thick crushed aggregate layer, respectively. Underlying the crushed aggregate layer was a 2 ft thick clay subgrade that had a 6% California Bearing Ratio. Simulated truck traffic was applied using ERDC’s heavy vehicle simulator–transportation with a dual-wheel tandem axle truck gear. Rutting performance and instrumentation response data were monitored at multiple traffic intervals. Observed rutting in the geogrid test items was approximately one-third of that in the unstabilized item, in which was a meaningful performance improvement. Instrumentation response data indicated that the geogrid inclusion pro-vided a stiffening effect that altered the anticipated pavement response. An analytical investigation showed that traditional layered elastic analysis techniques did not adequately describe the pavement response with geogrid inclusion. A robust model that included material nonlinearity and a geogrid interface model provided a closer approximation to the measured subsurface response.

29 Oct 2025

Beneficial Use of Contaminated Sediments: A Review of Technical, Policy, and Regulatory Needs

Abstract: This special report summarizes key results from the March 2024 Sediment Management Working Group (SMWG) Contaminated Sediment Beneficial Use Workshop sponsored by US Army Engineer Research and Development Center’s (ERDC’s) Advanced Materials and Substances of Emerging Environmental Concern (AMSEEC) center, a multilaboratory research collaborative reviewing solutions to environmental challenges, and the Dredging Operations Environmental Research (DOER) Program, the navigational dredging research arm of ERDC. The workshop focused on potential avenues for treatment and management of contaminated sediments to support expanded beneficial use (BU) opportunities. AMSEEC, with support from DOER, sponsored four pilot studies to advance the technical aspects of the workshop program and partnered with the SMWG, an industry consortium, to organize the workshop in Washington, DC. The workshop was attended by more than 75 practitioners and relevant stakeholders to review these pilot studies and the challenges of advancing treatment and management of contaminated sediment to support BU. This special report summarizes and prioritizes technical, regulatory, and policy needs to enable expanded BU opportunities for contaminated sediments.

29 Oct 2025

A Multigenerational Exposure of the Zebrafish (Danio rerio) to PFOS

Abstract: The ecological risk of PFOS in extended chronic and multigenerational exposures was quantified through survival, growth, reproduction, and vitellogenin (egg yolk protein precursor) responses as well as PFOS bioconcentration in zebrafish (Danio rerio). Fish were exposed to environmentally relevant PFOS concentrations through 180 days postfertilization (dpf) in the parental (P) and first filial (F1) generations and 16 dpf in the second filial (F2) generation. Survival decreased significantly in P and F2 generation exposures, but not F1, at the highest PFOS treatment. Significant adverse effects on body weight and length occurred predominantly at highest exposure treatment. Finally, PFOS had no significant effects on P or F1 egg production and survival or whole-body vitellogenin levels in P or F1 male fish. The present investigation indicated a threshold for ecologically relevant adverse effects in zebrafish at 119 μg/L (standard deviation [S.D.] 23 μg/L, n = 10) for survival and 87 μg/L (S.D. 48 μg/L, n = 19) for all statistically significant negative effects observed. Importantly, males had significantly increased PFOS accumulation and bioconcentration factors versus females in both P and F1 generations. PFOS transfer to eggs was not a depuration pathway. Finally, a toxicokinetic model was developed to reliably predict PFOS whole-body burdens.

24 Oct 2025

Hydraulic Evaluation of the Proposed Brandon Road Lock Flushing System

Abstract: The Great Lakes Mississippi River Interbasin Study is a US Army Corps of Engineers effort focused on stopping the migration of aquatic nuisance species (ANS) from the Mississippi River to the Great Lakes. Brandon Road Lock and Dam (BRLD) has been chosen as the location to stop this northward migration. The study described in this report focuses on the performance of a proposed lock flushing system intended to reduce the risk of ANS from passing northward through BRLD. This system is a modification of the existing filling/emptying (F/E) system and must perform as both a lock flushing system and the F/E system. This study focuses on determining the performance of the flushing system and the F/E system to establish flushing and F/E operating parameters for safe lock operation. The results presented include qualitative descriptions and quantitative measurements of the flushing and F/E systems’ hydraulic performance. Finally, this study investigates commercial barge tows entering and exiting the lock chamber to determine the effects such barge tow movement has on both the barge tow and the vessel-generated currents. This report provides recommendations for flushing system and F/E system operation and commercial barge traffic considerations during flushing.