26 Mar 2026

Development of a Three-Dimensional (3D) Hydrodynamic, Salinity, and Sediment Transport Model of the San Francisco Bay

Abstract: The US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory (ERDC-CHL), has developed the multimodule Adaptive Hydraulics (AdH) model for San Francisco Bay, incorporating hydrodynamics, salinity, and sediment transport. This model supports the US Army Corps of Engineers San Francisco District in navigation and sediment management, particularly for the development of a Regional Dredged Material Management Plan to assess dredging methods and placement alternatives. San Francisco Bay is a dynamic estuary shaped by strong tidal currents, seasonal freshwater inflows, and complex sediment transport. As a key hub for international maritime trade, its federal navigation channels require regular maintenance dredging. Dredged sediment plays a crucial role in sustaining mudflats, tidal marshes, and intertidal habitats that mitigate coastal flooding and provide ecological benefits. This report documents the development, application, and validation of the AdH-3D model for 2022, demonstrating its ability to reproduce observed hydrodynamic, salinity, and sediment conditions. It details the model setup, boundary conditions, and validation, ensuring its reliability for informing sediment management and navigation planning. The model serves as a valuable tool for evaluating long-term sediment fate and optimizing regional dredging strategies.

24 Mar 2026

LaGrange Lock and Dam Navigation Study: Ship Simulation Results

Abstract: Located at River Mile 80.2, approximately 8 mi south of Beardstown, Illinois, the LaGrange Lock and Dam is a wicket gate structure with a single tainter gate to control pool elevation. LaGrange was constructed in the 1930s to aid navigation on the Illinois River. Due to increased commercial traffic, its existing 600 ft lock is now inadequate. To address this, the US Army Corps of Engineers' Rock Island District and the Engineer Research and Development Center (ERDC) studied the feasibility of adding a new 1,200 ft lock chamber. Initial physical model studies were conducted between 2009 and 2010 and continued in 2023. In 2024, the Coastal and Hydraulics Laboratory (CHL) used the ERDC Watercraft and Ship Simulator for a feasibility study focusing on the approaches to the new lock. The goal was to assess the navigability of the proposed design under various conditions. By analyzing simulator data and pilot feedback, CHL worked to confirm the design's feasibility and ensure its construction would not adversely affect the existing structure, which will remain as an auxiliary chamber.

24 Mar 2026

Intraspecific Variation in Rapid Cold Hardening and Acclimation of the Adventive Parrot’s Feather Weevil, Phytobius (=Parenthis) Vestitus, in the Southern USA

Abstract: Plasticity in thermal tolerance, expressed through acclimation or rapid cold hardening, for example, provides organisms with a mechanism to deal with unexpected and often rapid changes in the thermal environment. Spatial variation in response to high or low temperatures may occur due to evolutionary adaptation, particularly if a fitness increase coincides with the ability to respond quickly to environmental change. Thermal tolerances of beneficial insects used for biological control dictate where and under what thermal conditions the insects will provide value to management programs. We investigated two aspects of thermal phenotypic plasticity in response to thermal conditions using four populations of the adventive parrot’s feather weevil, Phytobius vestitus, from the southern USA. At low temperatures, we determined the presence and variation in rapid cold hardening in one of the four populations using two temperature ramping rates. In contrast, at high temperatures, all P. vestitus populations displayed a significant heat acclimation response, documented as elevated loss of motor control and motor function temperatures after acclimation. Thus, observed patterns of plasticity differed between high and low temperatures and among source populations. These results demonstrate the presence of geographic variation in phenotypic plasticity in response to thermal environments and emphasizes the need to consider plasticity when selecting climate-adapted populations of biological control agents.

24 Mar 2026

Developing a Habitat Suitability Index with Field Data and Hydraulic Models

Abstract: Linking habitat availability with hydraulic models integrates river engineering in the ecological field. Field observation for species presence and physical habitat availability mapping is inherently limited due to time and access constraints for field data collection. This study leverages hydraulic modeling to supplement larval fish population monitoring data, effectively expanding mapped physical habitat and allowing for monitoring bias analysis. The inundation extents and character of streamflow from hydraulic modeling were used to refine habitat suitability indices relative to total habitat availability from discrete fish monitoring events. Given the flexibility in hydraulic modeling to simulate a range of flows, the habitat suitability index is then translated to an effective habitat curve according to areal inundation and hydrologic frequency. With this framework, forecasting the impacts of long-term trends, such as geomorphic or hydrologic change, can be reasonably and quantitatively assessed. This manuscript uses a case study of Rio Grande silvery minnow monitoring at restoration sites where the floodplain has been lowered via earthwork. Comparisons are made for habitat suitability indices developed from field observation data alone and field observation supplemented by hydraulic modeling. Known biases of field sampling data were confirmed based on simulated hydraulic conditions across entire restoration sites. In the case of Rio Grande silvery minnow, a heavily studied species, such field monitoring biases are an effective use of resources. However, this framework may be helpful for assessing alternative management approaches and monitoring strategies of species that are less studied.

24 Mar 2026

Unraveling the Dynamics of Shoaling Rates: A Statistical Analysis for Enhanced Waterway Maintenance along the Ohio River

Abstract: Waterway maintenance plays an important role in efficiently transferring goods. The maintenance decisions, including dredging, depend on the sediment accumulation that is highly dependent on the shoaling rate. The shoaling caused by tidal movement or channel characteristics can change the dredging depth. Therefore, a better understanding of shoaling rate distribution is a requirement to perform dredging more efficiently. This study proposes a wide range of statistical methods to analyze the model distribution of shoaling rates at reach and sub-reach levels along the Ohio River. The shoaling data is generated from the Corps Shoaling Analysis Tool (CSAT) developed by the US Army Corps of Engineers. This paper investigates the distribution shape and degree of symmetry of distribution to specify the appropriate distribution model for the shoaling rate. It also measures the fitting performances. The results show that the behavior of sub-reaches is different from that of the reach and depends on the location.

23 Mar 2026

Experimental Evaluation of Corroded Steel Beams Retrofitted with Fiber-Reinforced Polymers

Abstract: Corrosion represents one of the main threats to steel structures working in harsh conditions. It compromises the safety and integrity of marine structures, reducing their lifespan and increasing their maintenance cost. Recent studies investigated the use of fiber-reinforced polymers to repair corroded steel structures; however, these studies showed unmatured debonding behavior, stopping short of examining the impact of these repairs on the ductility of different steel elements. In this study, we conduct a series of full-scale experimental tests to investigate the impact of chemical corrosion on steel beams as well as the impact of repairing the beams using carbon fiber–reinforced polymer (CFRP) and basalt fiber–reinforced polymer (BFRP) in enhancing the beams’ structural performance. Corrosion, introduced to the beams’ tension flange and web elements, is used to establish a baseline dataset that captures the impact of repairs on corroded steel surfaces. The results show that the reduction of the flange and web section lowers the beams’ yielding load by 10% and 1%, respectively, compared with a beam with a full cross section. CFRP and BFRP patches can partially restore the corroded beams’ ductility; however, the fracture of the CFRP patches reduces the beam strength by 31% compared with its ultimate strength.

23 Mar 2026

OpenFOAM Verification and Validation: Quantifying Multiphase Flow Solvers for a U-Bend Simulation

Abstract: This report presents a validation and verification study of multiphase solvers in the open-source software, OpenFOAM, for an open-channel U-Bend simulation. The study’s primary objective quantified the performance and discrepancies between different Volume of Fluid (VoF) solvers to establish robust guidelines for US Army Corps of Engineers (USACE) water resource applications. The study compared the algebraic solver, interFoam, with the geometric solver, interIsoFoam, and interIsoFoam’s various interface reconstruction schemes. Key parameters such as the Courant number, numerical schemes, and the effect of a buoyancy-modified turbulence model were evaluated for their effect on computational cost and solution accuracy. The results demonstrated that interFoam is significantly more computationally efficient than interIsoFoam, particularly at lower Courant numbers. While velocity fields were qualitatively similar across all solvers, interIsoFoam consistently predicted a lower free-surface elevation. Including a buoyancy source term in the turbulence model improved interface sharpness and corrected the over-production of turbulent kinetic energy at a negligible computational cost. For the U-Bend case, choosing a specific geometric reconstruction scheme had minimal effect on the solution’s accuracy. Therefore, interFoam with a turbulence buoyancy term is recommended as a cost-effective and accurate approach.

23 Mar 2026

Assessment of Aluminum-Based Drinking Water Treatment Residuals from Multiple Utilities in the United States as Green Sorbents for PFAS

Abstract: Per- and polyfluoroalkyl substances are persistent environmental contaminants causing human health concerns. In this study, five aluminum-based drinking water treatment residuals were evaluated as green adsorbents for the removal of perfluorooctanoic acid and perfluorooctanesulfonic acid from water. Al-WTRs are nonhazardous solid wastes generated during the coagulation process of water treatment using aluminum salts or polymers. Although high PFAS adsorption capacity of Al-WTRs generated in one facility in the US has been reported, no study exists assessing PFAS adsorption capabilities of WTRs generated in multiple facilities using various types of aluminum coagulants. Batch adsorption experiments of PFOA and PFOS on Al-WTRs showed removal efficiencies exceeding 70 % for PFOA and 94 % for PFOS across all Al-WTRs. Maximum adsorption capacities for PFOS were significantly higher than those for PFOA, indicating the stronger affinity of the Al-WTRs for PFOS. Low desorption rates for both PFOA and PFOS suggested irreversible adsorption. Correlation analysis revealed that oxalate-extractable Al, Fe, and organic matter primarily contributed to PFOA adsorption, while pore size, oxalate-extractable Al, Fe, and total calcium primarily contributed to PFOS adsorption. These easily measurable parameters could be used as predictors when utilizing Al-WTRs as sustainable sorbents for PFAS removal. This study not only establishes the comparative and predictive performance of Al-WTRs from multiple utilities for PFAS sorption but also demonstrates their recycling potential within a circular-economy framework.

23 Mar 2026

Seamless Nearshore Topo-Bathymetry Reconstruction from Lidar Scanners: A Proof-of-Concept Based on a Dedicated Field Experiment at Duck, NC

Abstract: Accurate observations of the nearshore bathymetry, including within the breaking wave region, are critical for the prediction of coastal hazards, and improved understanding of sandy beach morphological response to storms. We implement the recent Boussinesq theory-based depth inversion methodology of Martins et al. (2023) to single- and multibeam lidar datasets collected during a dedicated field experiment on a sandy Atlantic Ocean beach near Duck, North Carolina. Compared with common approaches based on passive remote sensing technology, lidar scanners present several key advantages, including the capacity to directly measure the beach topography, waveforms and the cross-shore variations in mean water levels due to wave action, leading to the seamless reconstruction of a vertically-referenced beach topo-bathymetry. Given the potentially gappy nature of lidar data, particular attention is paid to the robust computation of surface elevation spectral and bispectral quantities, which are at the base of the proposed non-linear depth inversion methodology. Promising results on the final topo/bathymetry are obtained under contrasting wave conditions in terms of non-linearity and peak period, with an overall root-mean square error below 0.3 m obtained along a cross-shore transect covering both shoaling and breaking wave conditions. The accuracy of the final bathymetry in the shoaling and outer surf regions is generally found to be excellent, with similar skills as previously obtained in laboratory settings. Under the most energetic conditions, an underestimation of the wave phase velocity spectra is observed within the surf zone with all theoretical frameworks, potentially owing to surf zone vortical motions not yet accounted for in the present methodology. This underestimation of the wave phase velocities results in a relatively large overestimation of the mean water depth, between 30% to 100% depending on the theoretical framework. With the methodology described herein, lidars bring new perspectives for seamlessly mapping the nearshore topo/bathymetry, and its temporal evolution across a wide range of scales. Although currently limited to a single cross-shore transect, we believe that opportunities exist to integrate multiple remote sensors, which could address individual sensor limitations, such as coverage or the incapacity to directly measure waveforms.

19 Mar 2026

Compressed Snow Blocks: A Proof-of-Concept Study for Adapting Earth Block Technology for Cold Regions

Abstract: Snow construction plays a crucial role in military operations in cold regions, providing tactical fortifications, thermal insulation, and emergency infrastructure in environments where conventional building materials are scarce or require extensive infrastructure to support. Research into optimized snow compaction techniques has informed the design of snow-based protective structures, runways, and shelters. This study tested whether a conventional compressed earth block (CEB) machine could be used to produce compressed snow blocks (CSBs) suitable for construction applications in cold environments. The machine successfully formed CSBs with relatively consistent dimensions (i.e., block height), demonstrating feasibility and reliability in shaping snow for structural purposes. Density measurements of the snow blocks were more consistent with ice, indicating potential viability in load-bearing applications, but suggesting that the pressure applied during production may not be necessary to reach sufficient block strength depending on its intended end-use. While mechanical strength was not assessed, these initial findings support further investigation into optimizing this new snow compaction technique, the material properties, and block durability under environmental stressors (e.g., temperature fluctuations). Additional testing and development are required to refine this approach for faster, more efficient snow compaction for sustainable construction in cold regions.