11 Jul 2022

National Sediment Placement Data Viewer Users Guide

Purpose: This US Army Corps of Engineers (USACE) Regional Sediment Management (RSM) technical note serves as a user’s guide for the RSM National Sediment Placement Data Viewer. This application was created utilizing over 20 yr* of detailed and verified USACE dredging data, giving users an interactive web-based tool that takes these datasets and displays them on a national map, viewable at the district or project scale. The Data Viewer will quantify the total cubic yards dredged, disposed, and/or beneficially used based on the user selected parameters. Detailed information on the datasets utilized and the verification processes followed to create this application can be found in ERDC/TN RSM-22-4, USACE Navigation Sediment Placement: An RSM Program Database (1998 – 2019) (Elko et al. 2022). This technical note attempts to define each of the inputs/outputs given from the Data Viewer and then provide a step-by-step example of utilizing the Data Viewer, accessed here: https://www.arcgis.com/apps/MapSeries/index.html?appid=0ea8fc0a956f46068428c862e7497233

8 Jul 2022

Techniques for Developing Bars and Islands in Incising Channels

Abstract: Sandbars and islands provide important nesting and foraging habitat for birds (including listed species) and shallow water habitat for many aquatic species in riverine ecosystems. In-stream habitat is especially important in incised channels lacking floodplain connectivity, with channel bars providing important riparian habitat. However, some river management practices significantly alter and sometime eventually eliminate these important habitats. Several US Army Corps of Engineers districts are planning or actively building instream bars and islands using flow management and/or instream structures. Sister agencies (e.g., US Bureau of Reclamation) have similar initiatives downstream of their reservoir structures. This report outlines considerations for establishing and managing sandbar and island features. It presents a compilation of proven techniques for promoting sandbar and island development and for reducing erosion of these features.

7 Jul 2022

Validation of the Automatic Dynamic Cone Penetrometer

Abstract: The U.S. military requires a rapid means of measuring subsurface soil strength for construction and repair of expeditionary pavement surfaces. Traditionally, a dynamic cone penetrometer (DCP) has served this purpose, providing strength with depth profiles in natural and prepared pavement surfaces. To improve upon this device, the Engineer Research and Development Center (ERDC) validated a new battery-powered automatic dynamic cone penetrometer (A-DCP) apparatus that automates the driving process by using a motor-driven hammering cap placed on top of a traditional DCP rod. The device improves upon a traditional DCP by applying three to four blows per second while digitally recording depth, blow count, and California Bearing Ratio (CBR). An integrated Global Positioning Sensor (GPS) and Bluetooth® connection allow for real-time data capture and stationing. Similarities were illustrated between the DCP and the A-DCP by generation of a new A-DCP calibration curve. This curve relates penetration rate to field CBR that nearly follows the DCP calibration with the exception of a slight offset. Field testing of the A-DCP showed less variability and more consistent strength measurement with depth at a speed five times greater than that of the DCP with minimal physical exertion by the operator.

30 Jun 2022

Other Social Effects and Social Vulnerability Analysis: Existing Resources

Purpose: The following technical note (TN) provides a summary of existing resources available to the US Army Corps of Engineers’ (USACE) districts that address benefits in the Other Social Effects account for evaluating the effects of water resource projects. Consideration of social factors is key to a complete, robust, water-resources analysis, and these resources provide planners and project development teams with approaches and tools for their consideration. "social effects—the constituents of life that influence personal and group definitions of satisfaction, well-being, and happiness —OSE Primer, 3" This TN is limited in scope and does not cover ecosystem goods and services or environmental-quality metrics that can also be used to assess benefits outside of economic benefits from water-resource projects. The following resources and their associated metrics are presented in a manner that is focused on assisting districts during the project-planning phase, although the metrics can be used to assess benefits or impacts during other project phases as well (for example, construction, operations, and maintenance).

29 Jun 2022

Adversarial Artificial Intelligence: Implications for Military Operations

Introduction: Artificial intelligence and machine learning algorithms are at the forefront of current research to help military analysts deal with triaging ever larger amounts of data from deployed sensors. These automated approaches will become increasingly embedded into the military decision making process, which makes it crucial to understand how these algorithms generate outputs and how sensitive they are to perturbations during training or classification. In other words, humans must have a ‘theory of mind’ for these sets of approaches in order to begin to trust them enough to make life or death decisions. Research in this area is known as adversarial examples for artificial intelligence / machine learning. Previous works in this domain focused on degrading classification performance with respect to added noise to new data. Some of these works achieved notable results on image data by subtly increasing noise, such that the image appeared unaltered to the human eye, but significantly impacted performance (Athalye et al. 2017). Povolny and Trivedi (2020) achieved similar results, but made a small visually obvious change to induce a degradation in performance. One notable work examined the effects of an increase in physical scale of the sensed environment (such as the large areas recorded for remote sensing platforms) on adversarial perturbations (Czaja et al. 2018). This technical note (TN) describes an initial foray into understanding how physical changes to the appearance of military vehicles resulted in performance degradation for a convolutional neural network (CNN). The military vehicles chosen were the M2 Bradley Infantry Fighting Vehicle and the M1064 Mortar Carrier. As stand-ins for the actual vehicle, plastic scale models were used, each a 1/35 scale replica. The results of this research have yielded a curated training and test data set of images related to the M2 and M1064, trained models based on a combined ResNet / Inception implementation from the Keras project, and adversarial examples mocked up using the scale models with images taken by a smartphone.

28 Jun 2022

Two Years of Post-Project Monitoring of a Navigation Solution in a Dynamic Coastal Environment, Smith Island, Maryland

Abstract: In 2018, jetties and a sill were constructed by the US Army Corps of Engineers adjacent to the Sheep Pen Gut Federal Channel at Rhodes Point, Smith Island, Maryland. These navigation improvements were constructed under Section 107 of the Continuing Authorities Program. Material dredged for construction of the structures and realignment of the channel were used to restore degraded marsh. Following construction and dredging, 2 years of monitoring were performed to evaluate the performance of navigation improvements with respect to the prevention of shoaling within the channel, shoreline changes, and impacts to submerged aquatic vegetation (SAV). Technical Report ERDC/CHL TR-20-14 describes the first year of post-project monitoring and the methodologies employed. This report describes conclusions derived from 2 years of monitoring. While the navigation improvements are largely preventing the channel from infilling, shoaling within is occurring at rates higher than expected. The placement site appears stable and accreting landward; however, there continues to be erosion along the shoreline and through the gaps in the breakwaters. SAV monitoring indicates that SAV is not present in the project footprint, even though turbidity is comparable to the reference area. Physical disturbance of the bottom sediment during construction may explain SAV absence.

27 Jun 2022

Tar-Pamlico and Neuse River Basins, North Carolina, Geomorphic Summary Report

Abstract: The Tar-Pamlico and Neuse River Basins are neighboring basins in eastern North Carolina, both originating in the piedmont physiographic region, transitioning to coastal plains, and emptying into Pamlico Sound. The Pittsburgh District is responsible for the continued efforts to assist local sponsors with managing these basins and submitted a Water Operations Technical Support (WOTS) request. The WOTS program, funded by Headquarters, US Army Corps of Engineers, provides funding for the Coastal and Hydraulics Laboratory (CHL) to provide technical assistance to develop innovative solutions to water resource problems. The objectives of this study are to identify flood risk management alternatives to address the accumulation of woody debris in the channel systems. CHL compiled existing conditions information and researched current and potential new methods for managing woody debris to provide a comprehensive list of recommendations. The results and recommendations are provided in this document.

16 Jun 2022

Development of a Two-Dimensional HEC-RAS Sediment Model for the Chippewa River, Wisconsin, for Software Development and Sediment Trend Analysis

Abstract: This US Army Corps of Engineers (USACE) Regional Sediment Management technical note (RSM-TN) describes an RSM effort that converted a one-dimensional (1D) sediment transport model of the Chippewa River confluence with the Mississippi River into a two-dimensional (2D) model. This work leveraged recent sediment data collection and tested the new 2D sediment transport capabilities in the Hydrologic Engineering Center, River Analysis System (HEC-RAS) Version 6.0. In addition to the benefits of software testing, the resulting model developed through this effort can provide more accurate spatial and temporal information about sedimentation in the Mississippi River navigation channel and help inform future dredging strategies for the St. Paul District, USACE.

15 Jun 2022

Simulated Herbicide Spray Retention on Floating Aquatic Plants as Affected by Carrier Volume and Adjuvant Type

Abstract: Foliar delivery of herbicides is a common means for plant management in aquatic environments. Though this technique is decades old, little is known about vegetative spray retention relative to this application method. A more complete understanding of maximizing herbicide retention could lead to improved plant management while simultaneously decreasing pesticide load in aquatic environments. Therefore, outdoor mesocosm experiments were conducted in 2020 to evaluate the effect of adjuvant type on foliar spray retention in waterhyacinth [Eichhornia crassipes (Mart.) Solms]. Additionally, the effect of carrier volume on spray retention in waterhyacinth, waterlettuce (Pistia stratiotes L.), and giant salvinia (Salvinia molesta D.S. Mitchell) was documented. Spray deposition did not differ among the nine adjuvants tested; however, spray retention was reduced 6% to 11% when an adjuvant was excluded from the spray solution. The effect of carrier volume on spray retention in waterhyacinth, waterlettuce, and giant salvinia was also investigated. Decreases in spray retention were most sensitive to increased carrier volume in waterhyacinth, followed by giant salvinia and waterlettuce. Among species, spray retention potential, as determined by intercept estimates, was greatest in water-lettuce and giant salvinia regardless of carrier volume. Asymptotes estimates for waterhyacinth, waterlettuce, and giant salvinia were 33%, 46%, and 79% spray retention, respectively. In other words, spray retention was the lowest and remained relatively constant at these values for the high carrier volumes tested (935 and 1,870 L ha−1), which were likely due to the presence of pubescence on leaves and flatter leaf architecture represented by waterlettuce and giant salvinia compared to the glabrous vertical leaves of waterhyacinth. Future research will evaluate these concepts under field condition.

15 Jun 2022

Foundational Principles in the Development of AdH-SW3, the Three-Dimensional Shallow Water Hydrodynamics and Transport Module within the Adaptive Hydraulics/Hydrology Model

Abstract: This report details the design and development of the three-dimensional shallow water hydrodynamics formulation within the Adaptive Hydraulics/Hydrology model (AdH-SW3) for simulation of flow and transport in rivers, estuaries, reservoirs, and other similar hydrologic environments. The report is intended to communicate principles of the model design for the interested and diligent user. The design relies upon several layers of consistency to produce a stable, accurate, and conservative model. The mesh design can handle rapid changes in bathymetry (e.g., steep-sided navigation channels in estuaries) and maintain accuracy in density-driven transport phenomena (e.g., thermal, or saline stratification and intrusion of salinity).