21 Apr 2026

Review of Computational Fluid Dynamics Capabilities to Analyze the Behavior of Amphibious Vessels During Surf-Zone Transit

Abstract: This US Army Engineer Research and Development Center (ERDC), Coastal and Hydraulics Laboratory (CHL) Engineering Technical Note (CHETN) provides an overview of the state of computational fluid dynamics (CFD) techniques for the analysis of amphibious vessels transiting or interacting with the surf zone. In this CHETN we present (1) a background of the problem set, (2) a general discussion of CFD techniques available for the simulation and analysis of waterborne vessel response in water, (3) a discussion of CFD analysis of amphibious vessels in the surf zone, and (4) a discussion of combined scaled and CFD analysis of amphibious vessels in the surf zone.

20 Apr 2026

Multimethod Change-Detection Analysis Using Prithvi-EO-2.0: A Comparative Study of Traditional and Segmentation-Based Approaches for Vector Database Validation

Abstract: This technical note presents an evaluation of the performance of four change-detection methodologies, with a focus on validating and maintaining authoritative vector-feature databases using Earth observation data. In this study, we implemented traditional pixel-to-pixel change detection, feature-data-compliant segmentation, pixel-to-feature segmentation, and feature-to-pixel change detection, leveraging the Prithvi-EO-2.0 Vision Transformer model (Szwarcman et al. 2025), to analyze imagery from California’s Central Valley. The analysis of Sentinel-2 imagery from California’s Central Valley (in 2021–2023) demonstrated that there was a trade-off between sensitivity and reliability in the change-detection approaches: feature-to-feature methods achieved the highest sensitivity (0.637 average), while the feature-to-pixel approach provided the most reliable validation (0.280 average), exceeding the performance of traditional pixel-to-pixel methods (0.256 average).

20 Apr 2026

Utilizing Laser Diffraction for Soil Particle Size Analysis

Abstract: This US Army Engineer Research and Development Center (ERDC) technical note (TN) describes the process and methodology for utilizing laser diffraction to analyze soil samples. The effort fulfills an Intelligent Environmental Battlefield Awareness (IEBA) project’s need to validate the performance of a global soil boundary mapping methodology that was developed as part of the Integration task. To validate the methodology, soil samples were classified by grain size into a texture class and compared against soil maps created for a given study area. The goal of this effort was to develop a repeatable standard operating procedure for the Horiba Partica LA-960V2, a laser diffraction particle size analyzer, that would allow rapid soil analysis to be conducted by individuals without a soil science background. The Horiba Partica has been used for soil particle size analysis, but it is not common in the field. Therefore, only limited documentation details the analysis protocol for the system. This TN will discuss the methodology used to analyze soil samples and the challenges encountered with the Horiba Partica.

20 Apr 2026

Effects of Environmental Chemical Pollutants on Microbiome Diversity: Insights from Shotgun Metagenomics

Abstract: Chemical exposure in the environment can adversely affect the biodiversity of living organisms, particularly when persistent chemicals accumulate over time and disrupt the balance of microbial populations. In this study, we examined how chemical contaminants influence microorganisms in sediment and overlaying water samples collected from the Kinnickinnic, Milwaukee, and Menomonee Rivers near Milwaukee, Wisconsin, USA. We characterized these samples using shotgun metagenomic sequencing to assess micro-biome diversity and employed chemical analyses to quantify more than 200 compounds spanning 16 broad classes, including pesticides, industrial products, personal care products, and pharmaceuticals. Integrative and differential comparative analyses of the combined datasets revealed that microbial density, approximated by adjusted total sequence reads, declined with increasing total chemical concentrations. Protozoan, metazoan, and fun-gal populations were negatively correlated with higher chemical concentrations, whereas certain bacterial and archaeal populations showed positive correlations. As expected, sediment samples exhibited higher concentrations and a wider dynamic range of chemicals compared to water samples. Varying levels of chemical contamination appeared to shape the distribution of microbial taxa, with some bacterial, metazoan, and protozoan populations present only at certain sites or in specific sample types. These findings suggest that microbial diversity may be linked to both the type and concentration of chemicals present. Additionally, this study demonstrates the potential roles of multiple microbial kingdoms in degrading environmental pollutants, emphasizing the metabolic versatility of bacteria and archaea in processing complex contaminants such as polyaromatic hydrocarbons and bisphenols. Through functional and resistance gene profiling, we observed that multi-kingdom microbial consortia—including bacteria, fungi, and protozoa—can contribute to bioremediation strategies and help restore ecological balance in contaminated ecosystems. This approach may also serve as a valuable proxy for assessing the types and levels of chemical pollutants, as well as their effects on biodiversity.

20 Apr 2026

New Poe Lock Emergency Closure System Physical Model Study

Abstract: The US Army Corps of Engineers (USACE)–Detroit District (LRE) has begun the process of designing a new emergency bulkhead for Poe Lock in Sault Ste. Marie, Michigan, and has requested assistance from the US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, in determining the hydraulic loads the bulkhead will experience during operation. The US Army Engineer Research and Development Center has constructed a 1:25 scale physical hydraulic model to estimate the hydraulic forces on the bulkhead and pressure on the bulkhead sill during lowering operations. Multiple bulkhead lowering speeds and bulkhead lip designs have been tested over the course of the study. This report provides time histories of the hydraulic loads and bulkhead pressures throughout the bulkhead lowering operations. These results will inform the design of the emergency bulkhead and the size of its operating equipment.

20 Apr 2026

Surf Zone Hazards Before and After a Beach Nourishment in Virginia, USA

Abstract: Beach nourishment is the leading coastal protection technique in the United States to combat erosion, enhance resilience to storm surge, and maintain recreational value. Despite these benefits, anecdotal reports suggest that beach nourishments elevate the surf zone hazard to beach patrons by steepening the beach face and altering the shoreface morphology such that conditions are more favorable for rip current formation. This study analyzes lifeguard rescue reports collected on the United States Atlantic Coast before and after a 2019 beach nourishment in Virginia Beach, Virginia, to assess whether the nourishment was correlated with an increased hazard to beach patrons. The data indicate that regardless of nourishment status, rescues were most probable during periods of high rip current probability (moderate to large wave heights and low-obliquity wave angles), along with low water level. To formally quantify pre-versus post-nourishment hazards, the proportion of rescues observed in nourished versus unnourished beach zones was compared with bootstrapped distributions of the pre-nourishment rescue proportions. Although the proportion of rescues in the nourished section of the beach exceeds the pre-nourishment average, it is not outside the overall range of pre-nourishment values obtained by random resampling. Consequently, there is insufficient evidence to conclude that the existing coastal management beach nourishment strategy increased the hazard to beach patrons at Virginia Beach.

20 Apr 2026

A Simple Room-Temperature Refurbishment Method for Sulfated Lead-Acid Batteries Using Ammonium Acetate Treatment

Abstract: Current recycling paradigms of lead-acid batteries (LABs) involve the use of toxic, polluting, and energy- demanding processes. Here we report a novel strategy to refurbish LABs which failed due to the formation of hard sulfation on the anodes. We used ammonium acetate (NH4Ac) to selectively dissolve the water-insoluble lead sulfate (PbSO4) crystals which cause the hard sulfation from commercial LAB anodes and electrodeposit metallic lead on a new surface. The remarkable removal of hard sulfation was characterized by a combination of X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX). The treatment replenished a fresh LAB anode surface, recovering the capacity from ~0 % to 99 %. The dissolved Pb2+ was retrieved with an efficiency of >99.9 % through electrodeposition, completing a refurbishing process that minimizes the release of heavy metals into the environment. We demonstrated a proof-of-concept refurbishing of a full commercial LAB, which recovered 35 % of its capacity. With a noteworthy capacity renewal and minimal release of hazardous materials, NH4Ac refurbishing promises to be an environment-friendly and economic alternative recycling paradigm for the LAB industry.

20 Apr 2026

Permafrost Pore Structure and its Influence on Microbial Diversity: Insights from X-Ray Computed Tomography

Abstract: Soil pore structure plays a critical role in shaping soil microbial communities, which directly influence biogeochemical cycling. A notable impact of soil pore structure on microbial communities is the inverse relationship between microbial diversity and hydrological pore connectivity, where increased hydrological pore connectivity reduces microbial diversity. Although well-studied in temperate systems, the importance of hydrological pore connectivity on soil microbial community diversity in permafrost soils is largely unknown. Although once thought to be devoid of microbial activity, more recent advances demonstrate permafrost is an active ecosystem albeit less than most unfrozen soil. Thus, these principles that govern unfrozen soils could remain impactful in permafrost. In this study, our objective was to quantify permafrost pore structure and determine if the inverse relationship between soil hydrological pore connectivity and microbial diversity persists in permafrost. To address these objectives, we analyzed eight permafrost cores from three distinct sites in Alaska. To quantify soil pore characteristics, we scanned intact permafrost using X-ray computed tomography. The Euler characteristic number was used to measure pore connectivity and serve as a proxy for potential hydrological connectivity, as direct measurement of hydrological connectivity was not possible. DNA and RNA were extracted from the scanned permafrost and analyzed via amplicon sequencing of the 16S region to quantify the total and active microbial community diversity. We found that permafrost soil shares characteristics with temperate soils despite limits in our analytical resolution (i.e., at an instrument scanning resolution of 20 µm, only macro-scale features (>75 µm) could be quantified). For example, we found that pores in the range of 75–1000 µm are the dominant pore size class and a positive relationship between total porosity and pore connectivity. Additionally, we identified pore connectivity as a potential driver of microbial diversity and provided evidence that conditions before the formation of permafrost exert a strong legacy effect on currently observed permafrost microbial diversity. These insights help to explain how soil physical structure acts to influence microbial communities in this extreme environment.

17 Apr 2026

Restoring the Flexible Pavement Test Track to Monitor Impact of Military Ground Vehicles

Abstract: Full-scale tests for pavement design, construction, evaluation, and maintenance benefit from designated facilities where pavement elements can be controlled and monitored. A loop test track at the US Army Engineer Research and Development Center (ERDC) Vicksburg campus was constructed between September 1986 and September 1988. This report describes activities to restore that pavement test track through reconstruction. ERDC constructed a road structure consisting of 4 in. of asphalt concrete over 6 in. of aggregate base course over native subgrade material on the site of the original test track. The pavement structure was instrumented with earth pressure cells and moisture probes at the subgrade, or base, course interface. Material testing and as-constructed properties are documented herein to allow future traffic studies that use the constructed test track to create numerical simulations and calibrate their embedded models with real-world data. This report details construction activities and material properties for future reference.

15 Apr 2026

Satellite Image Quality Classification with ImageNet Transfer Learning and Data Fusion

Abstract: This Coastal and Hydraulics Engineering Tech Note (CHETN) documents the development of a convolutional neural network (CNN) to automate quality control on image classification, a process previously done by subject matter experts (SMEs), within the Littoral Zone Maneuver Support Tool (LZMST). LZMST was created to support rapid exploration of an unknown littoral region by analyzing global satellite data and wave and current models to best estimate the coastal conditions and help identify potential hazards. In support of this mission, images from Landsat-8 (Roy et al. 2014) and Sentinel-2a/2b (Drusch et al. 2012) are graded on their predicted usefulness for LZMST, which is usually done by expert selection. A CNN model is developed to automate this task, by utilizing transfer learning on a CNN using ImageNet (Krizhevsky et al. 2017) weights combined with a small data set of classifications from the CoastSat (Vos et al. 2019) python application. Because the expert selection of images is incredibly time consuming, the data set used to develop this tool was small (approximately 3,500 images), which can make creation of a data-driven algorithm difficult. This CHETN highlights the usefulness of using transfer learning to eliminate the need for large data sets and demonstrates that ImageNet weights can be successfully used to assist in quality detection on multispectral imagery from the Landsat-8 and Sentinel-2a/2b missions.