23 Apr 2026

Sediment Transport Modeling to Evaluate the Performance of a Dredged Channel at Pohoiki Bay, Hawaiʻi, Following the Kīlauea Lower East Rift Zone Eruption

Abstract: The Kīlauea volcano’s Lower East Rift Zone (LERZ), located approximately 20.5 miles south-southeast from Hilo on the Island of Hawaiʻi, erupted during the summer of 2018, destroying over 700 homes and advancing the shoreline east of the volcano into the Pacific Ocean. The recently formed lava field along the shoreline eroded into Pohoiki Bay, creating a black sand beach that closed access to a boat ramp that was vital to the local community. The US Army Corps of Engineers (USACE) Honolulu District, on behalf of the State of Hawaiʻi, requested the US Army Engineer Research and Development Center (ERDC) Coastal and Hydraulics Laboratory (CHL) conduct numerical modeling of the existing condition at and around the bay to evaluate the impact of dredging a channel through the beach to reconnect the boat ramp to the Pacific Ocean. The Coastal Modeling System (CMS) was used to evaluate the shoaling rates in the proposed channel. The model was validated with morphology change calculations from a sediment budget, and the results provide a range of possible shoaling rates in the channel. The results of this effort were used to inform the State of Hawaiʻi’s plans to complete construction of a dredged channel in November 2025.

23 Apr 2026

Towards an Improved Language for River Data Analysis: Demonstration for the Highly-Regulated Ohio River Basin

Abstract: We present the Network Analysis and Data Integration (NADI) System for extracting, organizing, analyzing, and visualizing river data with upstream/downstream relationships. The NADI System consists of a Geographical Information System (GIS) tool that uses spatial methods to generate the network, and a Domain Specific Language (DSL) that provides a concise and intuitive syntax for data analysis and is extensible through a plugin system. We demonstrate the capabilities of NADI using a case study of the Ohio River basin, showing it to be well-suited for large-scale metadata analysis based on river connections. The result of the case study shows that approximately half of the USGS streamflow gages in the Ohio Basin were constructed after dam(s) upstream, and only 35% of the gages remain without any dams upstream. These unaffected gages only account for 1.2% of the measured streamflow, showing the scarcity of natural streamflow data.

23 Apr 2026

Development of an Agnostic Reservoir Model to Explore Wildfire Impact on Water Quality

Abstract: Despite the growing global concern surrounding the havoc caused by wildfires, there are still prominent gaps in knowledge regarding fire effects on nearby waterways. An agnostic CE-QUAL-W2 model was developed to look at the impact of wildfires on reservoir water quality, with a focus on harmful algal blooms. The model was informed using ten years of meteorological data from sites in the Pacific Northwest, United States. Wildfire scenarios were generated (one each for May, June, July, August, and September) using changes in temperature, total suspended solids, nutrients, dissolved oxygen, organic matter, and solar radiation typical of wildfires, informed via literature review. Harmful algal blooms showed the most sensitivity to fires that occurred prior to the growing season, likely due to the influx of phosphate accumulating in the system prior to growth. However, accumulation of nutrients for fires after the growing season showed impacts on blooms the following year. Increases in total dissolved solids during the fire could potentially lead to delays in initial bloom timing due to temporary light limitation. Results from the model runs indicate that wildfires can impact reservoir water quality and bloom dynamics not only immediately, but for months to years following a wildfire.

23 Apr 2026

Hierarchical Rule-Base Reduction Fuzzy Control for Path Tracking Variable Linear Speed Differential Steer Vehicles

Abstract: A novel waypoint navigation controller for a skid-steer vehicle is presented, where the controller is a multiple input-multiple output nonlinear angular velocity and linear speed controller. Hierarchical rule-base reduction was used in defining the controller. This entailed selecting inputs/outputs, determining the most globally influential inputs, generating a hierarchy relating inputs, selecting only the rules corresponding to the hierarchy, and, in effect, designing a symmetric rule-base. This dramatically reduced the rule-base size, by 97.7%, while maintaining global operating environment coverage. The stability analysis proved the asymptotic stability of the closed-loop controller-vehicle system. In addition, test courses were used to examine the effects of steering disturbance, phase lag, and overshoot as expressed in root mean square error (RMSE) and max error (ME). Outdoor experimental results for the controller’s performance were contrasted with a benchmark waypoint navigation controller, pure pursuit, and a simpler implementation that only output linear speed. The controller was found to outperform the pure pursuit and simpler implementation experimentally by 72% and 50% in RMSE, 71% and 40% in ME, validating the controllers viability.

23 Apr 2026

Applications of Snow-Covered Areas from Unoccupied Aerial Systems (UAS) Visible Imagery: A Demonstration in Southeastern New Hampshire

Abstract: Remote sensing observations of snow-covered areas (SCA) are important for monitoring and modeling energy balances, hydrologic processes, and climate change. For an agricultural field, we produced 12 snow cover maps from UAS imagery during an approximately 3-week-long spring snowmelt period. SCA maps were used to characterize snow cover patterns, validate satellite snow cover products, translate satellite Normalized Difference Snow Index (NDSI) to fractional SCA (fSCA), and downscale satellite SCA observations. Compared to manually delineated SCA, the UAS SCA accuracy was 85%, with misclassifications due to shadows, ice, and patchy snow conditions. During snowmelt, UAS-derived maps of bare earth patches exhibited self-similarity, behaving as fractal objects over scales from 0.01 to 100 m2. As a validation tool, the UAS-derived SCA showed that satellite snow cover observations accurately captured the fSCA evolution during snowmelt (R2 = 0.93−0.98). A random forest satellite downscaling model, trained using 20 m Sentinel-2 NDSI observations and 20 cm vegetation and terrain features, produced realistic (>90%accuracy), high-resolution SCA maps. While similar to traditional Sentinel-2 SCA in most conditions, downscaling snow cover significantly improved performance during periods of patchy snow cover and produced more realistic bare patches. UAS optical sensing demonstrates the potential uses for high-resolution snow cover mapping and recommends future research avenues for using UAS SCA maps.

22 Apr 2026

Statistical Analysis of Large Format Additively Manufactured Polyethylene Terephthalate Glycol with 30% Carbon Fiber Tensile Data

Abstract: In large format additive manufacturing (LFAM), a keener understanding of the relationship between the manufacture method and material temperature dependency is needed for the production of large polymer parts. Statistical analyses supported by material properties and a meso-structural understanding of LFAM are applied to elucidate tensile data trends. The data from LFAM polyethylene terephthalate glycol with 30% carbon fiber (CF) (PETG CF30%) panels (diagonal, horizontal, and vertical in the x-y print plane) and injection-molded specimens tensile tested at six different testing temperatures (room temperature, 40 ◦C, 50 ◦C, 60 ◦C, 70 ◦C, and 80 ◦C) were used for statistical analyses. A standard deviation, a coefficient of variation, and a two-way and one-way analyses of variance (ANOVA) were conducted. The manufacturing method (44.2%) and temperature (47.4%) have a strong effect on the ultimate tensile strength, in which temperature (82.6%) dominates Young’s modulus. To explain the difference between the ultimate tensile strength of vertical, diagonal, and horizontal specimens at room temperature, a visual inspection of the specimen failure was conducted and the maximum stress at the crack tip was calculated analytically. The decreased strength in the diagonal specimens resulted from the reliance on interlaminar adhesion strength. Future work will consider the effect of the void space variation on tensile strength variance.

22 Apr 2026

An Interdisciplinary Overview of Levee Setback Benefits: Supporting Spatial Planning and Implementation of Riverine Nature-Based Solutions

Abstract: Nature-based solutions are increasingly recognized as multi-benefit strategies for addressing the critical sustainability challenges of the Anthropocene, including the climate emergency and biodiversity crisis. Mainstreaming NbS in professional practice requires strategic, landscape-level planning integrating multiple sources of benefits and their synergies and trade-offs. Levee setbacks (LS) are among the best-studied riverine NbS with recognized benefits for flood risk management, drought resilience, water quality management, recreational opportunities, and ecological restoration for biodiversity. Although awareness of the multifarious benefits of LS as forms of Natural Capital is growing, implementation remains ad-hoc and opportunistic. To address this critical implementation gap for one major example of NbS, we review and synthesize literature across diverse disciplines to provide an overview of the primary social, economic, and ecological mechanisms that affect the co-benefit delivery of LS projects. Next, to make this information relevant to NbS practitioners, we link these mechanisms to spatial metrics that can be used to approximate the relative magnitude of project benefits and costs across these mechanisms. Finally, we highlight examples of key synergies and trade-offs among benefits that should be considered for LS planning. This synthetic approach is intended to familiarize readers with the diverse potential benefits of LS, and provide an understanding of how to select and prioritize potential sites for further study and implementation. Synergies and trade-offs among important benefit drivers abound, and social equity concerns will be paramount in ensuring the successful implementation of LS and other NbS in the future.

22 Apr 2026

Juvenile Atlantic Sturgeon Survival and Movement in Proximity to an Active Cutterhead Suction Dredge

Abstract: The Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus has suffered population declines throughout its range. Many knowledge gaps exist regarding how to mitigate threats and better inform recovery efforts. This study examined survival of juveniles during their movements through river reaches undergoing channel maintenance dredging operations. During 2019 and 2020, 268 (30-71cm fork length) juvenile Atlantic Sturgeon were captured and released in proximity to an active cutterhead suction dredge at three sites within the James River, Virginia. Juveniles were captured, some presumed feeding, around 95-145m from the dredge in areas that could easily be avoided if the dredge created a stressful environment. No significant trends in catch-per-unit-effort were found when trawl catch was compared to a reference location or when monitoring gill net catch 100m down current of a dredge over a month-long period at one of the sites. Twenty-nine of the 229 gill net captures were implanted with acoustic tags and telemetry was used to track their movements throughout the river. Four telemetered juveniles tagged prior to this project were also detected moving within dredge operations. Cumulatively, tagged juveniles made at least 125 passes of the dredging operations with no evidence of mortality. All tagged juveniles still within the river were detected following the cessation of dredging. The results of this study support that age 1-2yr Atlantic Sturgeon show no avoidance behavior of areas 100m of an active cutterhead suction dredge and move past dredge operations with low-risk of mortality.

22 Apr 2026

Mesoscale Modeling and Parametric Studies of Concrete Materials

Abstract: This research focused on creating a mesoscale finite element model of concrete, treating it as a three-phase composite material composed of coarse aggregates, mortar, and the Interfacial Transition Zone (ITZ). The objective was to understand how these mesoscale structures influence the material's properties and responses under various loading conditions. The model simulated a normal-strength concrete with a compressive strength of approximately 27 MPa. The simulations included unconfined uniaxial compression, hydrostatic compression, uniaxial strain compression and triaxial compression, with the model's dimensions and boundary conditions mirroring those of laboratory tests on cylindrical specimens. The results from the simulations corresponded well with experimental data, validating the accuracy of the modeling method. Further parametric studies were conducted to examine how attributes like aggregate volume fraction and material properties impact the concrete's overall performance. This validated modeling provides a reliable pathway for optimizing concrete materials for specific uses, such as designing hardened structures for military applications. It also offers a method for estimating concrete properties when laboratory testing is limited or unavailable.

22 Apr 2026

Laboratory Performance Evaluation of Coarse Aggregates for Asphalt Concrete Mixtures

Abstract: An extensive laboratory evaluation was conducted to investigate the performance of coarse aggregates under different test methods. Test methods including the Los Angeles abrasion (LAA), sulfate soundness, Micro-Deval abrasion, aggregate crushing value, aggregate impact value, aggregate durability index, and aggregate slake durability were chosen to determine the aggregates’ resistance to abrasion, impact, crushing, and soundness. A total of twenty-five aggregate sources were included in the laboratory experiments, including seven different aggregate types (crushed gravel, gabbro, greywacke, granite, limestone, monzonite, and sandstone). The mineral composition of the aggregate sources was determined using X-ray diffraction (XRD) analyses. According to this study, the LAA test results were reasonable in screening out an aggregate source perceived as marginally resistant to abrasion. The sulfate soundness test results were ineffective in quantifying the quality of the different aggregate sources. Most alternative test methods identified similarly unacceptable aggregate sources, consisting mainly of aggregate types composed of carbonate minerals. Strong statistical correlations were not found among the aggregate test parameters. Recommendations were given to further investigate existing test requirements for the selection of coarse aggregates, particularly when using the sulfate soundness test method.