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  • Metal Accumulation Capacity in Indigenous Alaska Vegetation Growing on Military Training Lands

    Abstract: Permafrost thawing could increase soil contaminant mobilization in the environment. Our objective was to quantify metal accumulation capacities for plant species and functional groups common to Alaskan military training ranges where elevated soil metal concentrations were likely to occur. Plant species across multiple military training range sites were collected. Metal content in shoots and roots was compared to soil metal concentrations to calculate bioconcentration and translocation factors. On average, grasses accumulated greater concentrations of Cr, Cu, Ni, Pb, Sb, and Zn relative to forbs or shrubs, and bioconcentrated greater concentrations of Ni and Pb. Shrubs bioconcentrated greater concentrations of Sb. Translocation to shoots was greatest among the forbs. Three native plants were identified as candidate species for use in metal phytostabilization applications. Elymus macrourus, a grass, bioconcentrated substantial concentrations of Cu, Pb, and Zn in roots with low translocation to shoots. Elaeagnus commutata, a shrub, bioconcentrated the greatest amounts of Sb, Ni, and Cr, with a low translocation factor. Solidago decumbens bio-concentrated the greatest amount of Sb among the forbs and translocated the least amount of metals. A combination of forb, shrub, and grass will likely enhance phytostabilization of heavy metals in interior Alaska soils through increased functional group diversity.

  • Simultaneous Mapping of Coastal Topography and Bathymetry from a Lightweight Multicamera UAS

    Abstract: A low-cost multicamera Unmanned Aircraft System (UAS) is used to simultaneously estimate open-coast topography and bathymetry from a single longitudinal coastal flight. The UAS combines nadir and oblique imagery to create a wide field of view (FOV), which enables collection of mobile, long d Coastal mapping, multiview stereo (MVS), nearshore morphology, remote sensing, structure from motion (SfM), Unmanned Aircraft Systems (UAS)well timeseries of the littoral zone suitable for structure-from motion (SfM), and wave speed inversion algorithms. Resultant digital surface models (DSMs) compare well with terrestrial topographic lidar and bathymetric survey data at Duck, NC, USA, with root-mean-square error (RMSE)/bias of 0.26/–0.05 and 0.34/–0.05 m, respectively. Bathymetric data from another flight at Virginia Beach, VA, USA, demonstrates successful comparison (RMSE/bias of 0.17/0.06 m) in a secondary environment. UAS-derived engineering data products, total volume profiles and shoreline position, were congruent with those calculated from traditional topo-bathymetric surveys at Duck. Capturing both topography and bathymetry within a single flight, the presented multicamera system is more efficient than data acquisition with a single camera UAS; this advantage grows for longer stretches of coastline (10 km). Efficiency increases further with an on-board Global Navigation Satellite System–Inertial Navigation System (GNSS-INS) to eliminate ground control point (GCP) placement. The Appendix reprocesses the Virginia Beach flight with the GNSS–INS input and no GCPs.

  • USACE celebrates National Park and Recreation Month

    July was National Park and Recreation Month – a month designed to tell the parks and recreation

  • Gathright Dam’s second pulse release set for Wednesday

    COVINGTON, Va. – Gathright Dam operators are scheduled to conduct the year’s second water-pulse release from Lake Moomaw on Wednesday, August 11.

  • Corps plans Depoe Bay dredging, after environmental assessment

    The U.S. Army Corps of Engineers will begin dredging Depoe Bay, Ore. to remove 2,000 cubic yards of material between September 13 and the end of the month. The work will take place for seven to 14 days and is an effort, with the City of Depoe Bay, to clean out the sediment catch basin.

  • HSDRRS levee lift Final General Re-evaluation Reports available for review

    The New Orleans District, U.S. Army Corps of Engineers released the final version of the Lake Pontchartrain & Vicinity and West Bank & Vicinity General Re-evaluation Reports for a 30-day review beginning Aug. 6, 2021.

  • Army Corps, Prince George’s County sign agreement, moving Anacostia Watershed restoration forward

    The U.S. Army Corps of Engineers (USACE), Baltimore District, and Prince George’s County Department of the Environment (DoE) have signed a Design Agreement that allows for the next steps in restoring the Anacostia Watershed in the county, which has suffered from years of environmental neglect.

  • Frank Russell Campground Adjusts Reservation Period for Flint Ridge Loop

    Mark Twain Lake, August 6, 2021 – The U. S. Army Corps of Engineers announces that Frank Russell campsites 30 through 48 (in Flint Ridge Loop) will be available for reservations until September 8, 2021. The remaining Flint Ridge sites 49 through 60 will be open until November 1, 2021. Joanna and Clear View Loops close on September 27, 2021. Make your reservations at www.recreation.gov or telephone 877-444-6777.

  • Army Corps updates water release schedule at Francis E. Walter Dam

    The U.S. Army Corps Engineers’ Philadelphia District updated the 2021 Francis E. Walter Dam recreation plan. The Army Corps updated the plan, which states whitewater and fisheries releases will be scheduled if enough water storage is accumulated in the reservoir.

  • Print Time vs. Elapsed Time: A Temporal Analysis of a Continuous Printing Operation for Additive Constructed Concrete

    Abstract: In additive construction, ambitious goals to fabricate a concrete building in less than 24 hours are attempted. In the field, this goal relies on a metric of print time to make this conclusion, which excludes rest time and delays. The task to complete a building in 24 hours was put to the test with the first attempt at a fully continuous print of a structurally reinforced additively constructed concrete (ACC) building. A time series analysis was performed during the construction of a 512 ft2 (16’x32’x9.25’) building to explore the effect of delays on the completion time. This analysis included a study of the variation in comprehensive layer print times, expected trends and forecasting for what is expected in future prints of similar types. Furthermore, the study included a determination and comparison of print time, elapsed time, and construction time, as well as a look at the effect of environmental conditions on the delay events. Upon finishing, the analysis concluded that the 3D-printed building was completed in 14-hours of print time, 31.2- hours elapsed time, a total of 5 days of construction time. This emphasizes that reports on newly 3D-printed constructions need to provide a definition of time that includes all possible duration periods to communicate realistic capabilities of this new technology.