1 Dec 2020

Army Corps of Engineers announces Chiefs Report signing for the Hudson River Habitat Restoration Study

Lt. Gen. Scott A. Spellmon, USACE Commanding General and 55th U.S. Army Chief of Engineers, has signed the Hudson River Habitat Restoration Ecosystem Restoration Chief’s Report representing the completion of the study and making it eligible for congressional authorization.

1 Dec 2020

Seamless Digital Elevation Model (DEM) Creation for the Mississippi River in Louisiana to Support Hydrologic Modeling

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1 Dec 2020

Vibration Survey of Room 47 with a Laser Doppler Vibrometer: Main Laboratory Basement, U.S. Army ERDC-CRREL

ABSTRACT:  Plans are underway to create an acousto-optic laboratory on the campus of the Cold Regions Research and Engineering Laboratory. For this purpose, existing space in the basement of the Main Laboratory will be renovated. Demanding measurement techniques, such as interferometry, require a sufficiently quiet vibration environment (i.e., low vibration levels). As such, characterization of existing vibration conditions is necessary to determine vibration isolation requirements so that highly sensitive measurement activities are feasible. To this end, existing vibro-acoustic conditions were briefly surveyed in Room 47, a part of the future laboratory. The survey measured ambient noise and ambient vertical floor vibrations. The ambient vibration environment was characterized according to generic velocity criteria (VC), which are one-third octave band vibration limits. At the time of the survey, the ambient vibration environment fell under a VC-A designation, where the tolerance limit is 2000 µin/s across all one-third octave bands. Under this condition, highly sensitive measurement activities are feasible on a vibration-isolated working surface. The conclusion of this report provides isolation efficiency requirements that satisfy VC-E limits (125 µin/s), which are necessary for interferometric measurements.

1 Dec 2020

Improving Design Methodologies and Assessment Tools for Building on Permafrost in a Warming Climate

Abstract: The U.S. Department of Defense (DoD) operates numerous Arctic and Subarctic installations, including Alaska. Changes to permafrost can threaten critical built infrastructure. It is critical to accurately characterize and compare site conditions in permafrost regions to enable the efficient, cost-effective design and construction of an infrastructure well suited to the permafrost environment and that meets DoD requirements. This report describes three research efforts to establish (1) field investigation approaches for ground ice detection and delineation, (2) methods and modeling for early warning detection of thawing permafrost under infrastructure, and (3) an outline of a decision support system that determines the most applicable foundation design for warming and degrading permafrost. Outcomes of these interrelated efforts address needs to improve construction of DoD mission critical infrastructure on Arctic and Subarctic permafrost terrains. Field investigation processes used systematic methodologies including borehole data and geophysical measurements to effectively characterize subsurface permafrost information. The Permafrost Foundation Decision Support System (PFFDSS) tool implements and logically links field survey information and foundation type assessments. The current version of PFFDSS is designed to be accessible to design-engineers of a broad range of experience, that will reduce the effort and cost, and improve the effectiveness of site assessment.

1 Dec 2020

Formulation of a Multi-Scale Watershed Ecological Model Using a Statistical Approach

Abstract: The purpose of this special report is to provide a statistical stepwise process for formulation of ecological models for application at multiple scales using a stream condition index (SCI). Given the global variability of aquatic ecosystems, this guidance is for broad application and may require modification to suit specific watersheds or stream reaches. However, the general statistical treatise provided herein applies across physiographies and at multiple scales. The Duck River Watershed Assessment in Tennessee was used, in part, to develop and test this multiscale, statistical approach; thus, it is considered a case example and referenced throughout this report. The findings of this study can be utilized to (1) prioritize water-sheds for restoration, enhancement, and conservation; (2) plan and conduct site-specific, intensive ecosystem studies; and (3) assess ecosystem outcomes (that is, ecological lift) applicable to future with and without restoration actions including alternative, feasibility, and cost-benefit analyses and adaptive management.

1 Dec 2020

Evaluation of New Endothall and Florpyrauxifen-benzyl Use Patterns for Controlling Crested Floating Heart and Giant Salvinia

Purpose: The purpose of this research was to (1) evaluate concentration exposure time (CET) relationships for florpyrauxifen-benzyl (ProcellaCOR) for control of the floating leaved plant crested floating heart (Nymphoides cristata, CFH) and (2) evaluate foliar applications of endothall (Aquathol K) for control of CFH and the floating fern giant salvinia (Salvinia molesta).

1 Dec 2020

Snow-Covered Obstacles’ Effect on Vehicle Mobility

ABSTRACT:  The Mobility in Complex Environments project used unmanned aerial systems (UAS) to identify obstacles and to provide path planning in forward operational locations. The UAS were equipped with remote-sensing devices, such as photogrammetry and lidar, to identify obstacles. The path-planning algorithms incorporated the detected obstacles to then identify the fastest and safest vehicle routes. Future algorithms should incorporate vehicle characteristics as each type of vehicle will perform differently over a given obstacle, resulting in distinctive optimal paths. This study explored the effect of snow-covered obstacles on dynamic vehicle response. Vehicle tests used an instrumented HMMWV (high mobility multipurpose wheeled vehicle) driven over obstacles with and without snow cover. Tests showed a 45% reduction in normal force variation and a 43% reduction in body acceleration associated with a 14.5 cm snow cover. To predict vehicle body acceleration and normal force response, we developed two quarter-car models: rigid terrain and deformable snow terrain quarter-car models. The simple quarter models provided reasonable agreement with the vehicle test data. We also used the models to analyze the effects of vehicle parameters, such as ground pressure, to understand the effect of snow cover on vehicle response.

30 Nov 2020

Upper Mississippi River 2020 navigation season comes to an end

ST. PAUL, Minn. – The U.S. Army Corps of Engineers, St. Paul District, locked its last tow of the season today, Nov. 30, to end the navigation season on the Upper Mississippi River.

30 Nov 2020

Hunting tips at Tuttle Creek Lake

The peak of hunting season is upon us and the U.S. Army Corps of Engineers, Kansas City District wish to help visitors prepare for their trips to Tuttle Creek Lake which offers nearly 20,000 huntable acres. Visitors are encouraged to prepare in advance and observe all regulations for our shared safety and protection of natural resources.

30 Nov 2020

Army Corps seeks public comment on modified permit process for activities in Maryland

The U.S. Army Corps of Engineers, Baltimore District, released for public comment their proposal to issue Maryland State Programmatic General Permit – 6 (MDSPGP-6) Nov. 23, 2020.