2 Apr 2026

Analyzing Historical Snow Trends in Interior Alaska

Abstract: This study examines 40 years (water years 1982–2021) of snowpack characteristics to consider its hydrological implications in the 5350 km² Chena River basin. Using observations and a fine-scale physics model, we analyzed trends of snow water equivalent (SWE), snow onset and disappearance, and snow cover duration (SCD). New hydrological insights for the region: Results indicate a decline in SWE across the modeled domain, averaging a decrease of 3 mm per decade, with larger decreases (up to 10 mm per decade) at lower elevations. While domain-averaged SWE trends were not statistically significant, observed SCD showed statistically significant decreases: - 5.2, - 5.0, and - 4.4 days per decade at Teuchet Creek, Fairbanks F.O., and Little Chena Ridge, respectively. Notably, observations at SNOTEL stations and modeling revealed no statistically significant change in domain-averaged Rain-on-Snow (ROS) events over the 40-year period, contrasting some regional future estimates of increased ROS frequency. Peak streamflow did not consistently correlate with peak SWE levels, suggesting that other environmental factors such as ROS events and rapid temperature increases (e.g., a 10◦C spike observed in 1992) are key drivers of hydrological outcomes. These findings improve understanding of complex subarctic hydrological processes impacting permafrost and highlight the need for adaptive water resource management to mitigate multi-factor risks like flooding and wildfire, requiring proactive planning.

2 Apr 2026

Storylines for the 1997 New Year’s Flood: The role of Watershed Antecedent Conditions and Future Warming in Shaping Discharge in the Truckee River Watershed

Abstract: The 1997 New Year’s flood was among the most devastating floods in the Truckee River watershed located in western Nevada. This event resulted from complex interactions of flood drivers, such as extreme precipitation, wet antecedent watershed conditions, warm temperatures and rapid snowmelt. We leveraged simulated forcings from the regionally refined mesh capabilities of the Energy Exascale Earth System Model (RRM-E3SM) and a process-based hydrological model to recreate the 1997 New Year’s flood for the Truckee River watershed across four climate warming levels ranging from the current temperatures to + 4◦ C. For each scenario, we conducted ensemble simulations with the same forcing but with 100 different seasonal watershed antecedent conditions, which were randomly sampled from long-term hydrological simulations. The results show that the 1997 New Year’s flood can be reproduced or exceeded consistently only when the antecedent watershed conditions are wet, specifically when streamflows are above the 75th percentile of the climatological value. There is negligible change in ensemble mean peakflows for Truckee River near Reno; however, there are increases of 18% and 14% under the warming levels of + 3◦ C and + 4◦ C, respectively. The increases in peakflows under future climate warming are attributed to wetter antecedent watershed conditions and enhanced snowmelt. Furthermore, the largest increases in peakflows occur at small, high-elevation headwater basins along the Sierra Nevada crest. This study highlights that changes in extreme flood events will result from the complex interplay of multiple flood drivers. It also demonstrates the potential of storyline approaches to analyze future realizations of these extreme events under different climate scenarios.

30 Mar 2026

Water Injection Dredging—Screening for Suitability: Research and Development of Screening Criteria to Determine the Suitability of Water Injection Dredging

Abstract: Innovative technologies for sediment management could reduce dredging costs and enhance benefits from sediment resources. Water injection dredging (WID) has the potential to improve sediment management in channels and reservoirs in the United States, but conditions for feasibility and favorable applications must first be established. WID works by fluidizing a sediment bed, causing it to flow down gradient or to spread as a density current. Fluidization testing on a range of sediments shows that the liquidity index might be an effective indicator of a sediment’s susceptibility to fluidization via WID. To assess the anticipated effectiveness of WID, a series of experiments were conducted to evaluate the fluid mud properties of sediment from Tuttle Creek Lake, Kansas, where WID has been proposed for reservoir management. Laboratory investigations were conducted to evaluate settling characteristics, viscosity, and angles of repose of the fluid mud over a range of concentrations. Large-scale flume experiments were also conducted to track the velocity and slope of the density current. Results were used to evaluate the flow characteristics of a density current generated by WID.

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

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

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

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.

17 Mar 2026

Estimating the Value of Virtual Aids to Navigation (VATONs) Deployed by the USACE LOMA Program near Lake Providence, Louisiana

Abstract: The purpose of this US Army Engineer Research and Development Center (ERDC) technical note (TN) is to estimate the value of a Virtual Aid to Navigation (VATON) as deployed from a mobile trailer by the Lock Operations Management Application (LOMA) program, operated through the ERDC Coastal and Hydraulics Laboratory (CHL). Estimates are developed based on the observed vessel traffic that transited the waterway during VATON deployment, historical information about vessel cargo movements and cargo value, and a mobile trailer cost estimate of $50,000.

13 Mar 2026

John H. Overton Lock and Dam, Red River: Lower Navigation Approach Physical Model

Abstract: The US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory (ERDC-CHL) conducted a physical model study of the John H. Overton Lock and Dam to optimize the navigation conditions in the lower lock approach. ERDC built a 1:100 Froude scale model to evaluate the navigation conditions for tows entering and exiting the lower lock approach. The final design consisted of two submerged rock dikes implemented approximately 1,500 and 3,000 ft downstream of the dam’s crest. The larger submerged rock dike was parallel to the channel, located in a scoured area at the downstream end of the riprap channel bed, and contained a crest elevation of approximately 15 ft, North American Vertical Datum of 1988 (NAVD 88). The smaller submerged rock dike extended from the most upstream end of the first rock dike, diagonally crossing the channel to the right-descending bank, and contained a crest elevation of approximately 30 ft, NAVD 88. The model provided data regarding tow tracks, current direction, and velocity information for various possible optimizations to the dam’s lower lock approach.