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  • PUBLICATION NOTICE: A Proposed Ecosystem Services Analysis Framework for the U.S. Army Corps of Engineers

    Abstract: Ecosystem goods and services (EGS) have been promoted as a way to effectively examine tradeoffs and improve communication of project-related environmental outcomes in terms of human well-being. This document proposes a framework to inform the development of any future guidance to U.S. Army Corps of Engineers (USACE) District planners for projecting changes in EGS from proposed civil works activities. The framework offers an analytical and communications approach for incorporating EGS in USACE decision-support processes. The core of the framework is a conceptual model that establishes a series of causal relationships that link management actions to EGS benefits/damages, applying economic concepts in both monetary and non-monetary benefit relevant indicators. The six-step planning process is used to demonstrate how the EGS framework might be integrated into existing analytic approaches and modified to fit different levels of resource availability and decision contexts. A hypothetical case study is used to demonstrate analytic techniques. The framework is compatible with goals to create a single decision-support document covering National Environmental Policy Act requirements and planning objectives when comparing project alternatives. The example is intended to generally illustrate the use of EGS in any type of program planning or project evaluation.

  • PUBLICATION NOTICE: Concept for Artificial Freezing of Sea Ice at Winter Quarters Bay, Antarctica

    ABSTRACT:  McMurdo Station serves as a major research and logistics hub for the United States Antarctic Program (USAP). Adjacent to the Station is Winter Quarters Bay (WQB), where vessels dock to unload cargo and fuel. The ice pier at McMurdo is essential for this annual vessel resupply but represents a failure potential, occasionally breaking up during or immediately after vessel operations. This study aimed to determine the feasibility of using thermopiles, a passive cooling technology, to artificially freeze seawater to “grow” the existing WQB bottomfast-ice edge so that ships can dock directly against it. Finite element simulations using modeling-parameter assumptions indicate that each row of thermopiles can grow a frozen wall to a depth of 9 m in about a month if installed on 1 July with an initial sea-ice thickness of 1 m and a thermopile spacing of 1.5 m. For our simulation scenarios, we approximate that it would take 255 to 820 days to complete a 40 m by 140 m wedge of bottomfast ice. The estimated cost ranges from about $600,000 to $1,600,000. These results serve as a preliminary feasibility study of successfully using thermopiles for generating a direct docking bottomfast-ice wharf at McMurdo.

  • PUBLICATION NOTICE: Sediment Sorting by Hopper Dredging and Pump-Out Operations: Sampling Methods and Analysis

    Abstract: Hopper dredging operations for beach and nearshore placement typically include periods of overflow, which produces some degree of separation between the size fractions of the dredged sediment. The degree of separation and the controlling factors are presently poorly known. This report focuses on laboratory experiments aimed at determining (1) suitable sampling methods on a dredge, (2) composite sampling techniques to reduce analysis cost, (3) associated sampling intervals to achieve suitable sediment representation of a hopper load, and (4) a hydraulic means of sample splitting. Results showed that no statistical difference exists among the three methods used to sample the hopper weir overflow. The method used to sample deposited hopper sediment identified a bias in the percent fines that resulted from flow sheltering. Further, it was found that composited samples were able to quantify the concentration and percent fines accurately, although an analytical data experiment showed that the accuracy of a composited sample is dependent on the sampling intervals. The accuracy of the fines and concentration from a hydraulic sample splitter was found to be dependent on median grain size, with fine sediment being evenly distributed and coarser sediment increasing the error in concentration and grain size distribution.

  • PUBLICATION NOTICE: Site-Specific Case Studies for Determining Ground Snow Loads in the United States

    ABSTRACT:  The U.S. Army Cold Regions Research and Engineering Laboratory (CRREL) has mapped ground snow loads for much of the United States. In some areas where extreme local variations preclude mapping on a national scale, instead of loads, “CS” is used to indicate that Case Studies are needed. This report and the accompanying spreadsheet, which contains the 15,104-station CRREL ground snow load database, provide the information needed to conduct Case Studies. When the latitude, longitude, and elevation of a site of interest are provided, the spreadsheet tabulates data available in the vicinity and generates plots that relate ground snow loads nearby to elevation. With this information, the ground snow load at the site of interest can be determined. This report uses 10 examples to illustrate the methodology and provides our answer and the comments we generate for each of these Case Studies and for 16 additional sites of interest, 8 of which have their answers “disguised” for practice purposes. CRREL has conducted over 1000 Case Studies upon request. Practicing structural engineers were involved in over 250 of them to verify that this methodology is ready to transfer to the design profession.

  • PUBLICATION NOTICE: Understanding State-of-the-Art Material Classification through Deep Visualization

    Abstract: Neural networks (NNs) excel at solving several complex, non-linear problems in the area of supervised learning. A prominent application of these networks is image classification. Numerous improvements over the last few decades have improved the capability of these image classifiers. However, neural networks are still a black-box for solving image classification and other sophisticated tasks. A number of experiments conducted look into exactly how neural networks solve these complex problems. This paper dismantles the neural network solution, incorporating convolution layers, of a specific material classifier. Several techniques are utilized to investigate the solution to this problem. These techniques look at specifically which pixels contribute to the decision made by the NN as well as a look at each neuron’s contribution to the decision. The purpose of this investigation is to understand the decision-making process of the NN and to use this knowledge to suggest improvements to the material classification algorithm.

  • MKARNS Nav Notice SWL 20-50 Lock 3 Sailing Instruction Lifted

    MKARNS - The sailing instruction for the downstream approach to Joe Hardin Lock (No. 3) NM 50.2, as noted in Navigation Notice SWL 20-42 has been lifted.

  • Public meetings in virtual environment: Meeting CERCLA milestones for FUDS projects

    For environmental cleanup projects, public involvement is required at specific stages of response

  • Corps hosts public meeting Aug. 27 with update on Central Everglades Planning Project South Phase

    The U.S. Army Corps of Engineers Jacksonville District, will host a virtual public meeting Aug. 27 to share information about progress on the Central Everglades Planning Project South (CEPP South) phase via webinar and teleconference.

  • New recommended system for Ala Wai project evaluated in technical report

    The U.S. Army Corps of Engineers (USACE) Honolulu District completed an Engineering Documentation Report Aug. 6 that provides the new recommended plan for the Ala Wai Flood Control Project.

  • El Cuerpo de Ingenieros anuncia la firma del Reporte Final para el estudio de reducción de inundaciones del Rio Culebrinas

    El Cuerpo de Ingenieros del Ejército de los Estados Unidos (USACE por sus siglas en inglés), anuncia que el Teniente General Todd T. Semonite, comandante general, ha firmado el “Chief’s Report” para el estudio de reducción de inundaciones del Rio Culebrinas en Puerto Rico. La firma de este informe significa un momento crucial y avanza el proyecto al Congreso para la autorización individual.