9 Oct 2024

Performance of High-Resolution, Acoustic Mapping Systems in a Fluid-Mud Environment : Testing the Effectiveness and Viability of High-Resolution, Hydrographic Survey Systems in a Fluid-Mud Environment

Abstract: This study explores the use of high-resolution acoustic mapping systems to penetrate fluid-mud layers by quantitatively relating depth with operating frequency. Prior to this study, multibeam surveys have proven be an effective method to elucidate the seafloor and collect bathymetric data on various bodies of water including rivers, lakes, bays, and the oceans. These techniques are regularly used on US Army Corps of Engineers dredged and federally maintained navigation channels. The objective of the study was to test the effectiveness of commercial off-the-shelf, low-frequency, high-resolution acoustic survey systems to penetrate fluid mud and if so, determine the density at penetration. The testing method combined multibeam echosounder, sub-bottom profiler, and single-beam echo sounder. In addition, in situ testing was conducted to determine the density of fluid-mud layers using a RheoTune profiler and laboratory testing. Results indicate that the use of currently available, bathymetric mapping systems operating at 90 kHz and higher are incapable of penetrating fluid mud in riverine and coastal shallow water conditions. This study demonstrates that while multibeam technology is effective at penetrating the water column, current frequencies available on the market are unable to penetrate fluid-mud layers in a riverine and shallow-water environment.

3 Oct 2024

Comite Diversion Numerical Model Study

Abstract: The Comite River diversion project is designed to reduce flooding along the Comite and Amite Rivers during flood events by diverting flow from the Comite River into the Mississippi River above Baton Rouge, Louisiana. The flow is diverted from the Comite River along a diversion canal to the Lilly Bayou Control structure. This structure allows the Comite River flow to enter the Mississippi River floodplain. A numerical model was created to evaluate the impacts associated with this addition of water to the Mississippi River. A 2D Adaptive Hydraulics numerical model was created to quantify the system impacts associated with the diverted flow in conjunction with possible system modifications to control the flow pathway. The impact of the diversion was determined to be heavily dependent on the flow and stage of the Mississippi River. At higher stages and flows, the flow diverted by the Lilly Bayou Control structure is negligible in relation to the much larger Mississippi River flow and therefore the impacts of the added flow are significantly less than at lower Mississippi River stages. At lower Mississippi River flows and stages, the added flow from the Lilly Bayou Control structure has a larger impact on the inundation due to the larger relative amount of diverted flow in relation to the Mississippi River. Ultimately, the diverted Comite River flow has some incremental increase in water levels at all Mississippi River stages.

27 Sep 2024

Potential Engineering With Nature Features to be Incorporated at Woodtick Peninsula

Purpose: Woodtick Peninsula is a barrier peninsula in western Lake Erie where restoration activities are being planned to combat erosion of the peninsula wetlands through placement of dredged material. As part of the restoration effort, design of an artificial reef is currently underway to function as a breakwater, preventing erosion of the fine-grained material being hydraulically placed along the west side of the peninsula. To the extent possible, it is desirable to design the reef such that it would not only provide erosion protection, but also incorporate features that would provide habitat, and thereby support the goals of Engineering With Nature® (EWN®). EWN is a concept focused on aligning natural and engineering processes to deliver economic, environmental, and social benefits efficiently and sustainably through collaboration. A range of breakwater and shoreline armoring alternatives have been utilized in coastal environments to enhance habitat. While a number of alternatives have been successfully demonstrated in marine waters, fewer structures have been adapted to freshwater systems of the Great Lakes. However, there have been several demonstrations within the Great Lakes in which breakwater structures have been enhanced to incorporate habitat features. In this report, potential designs for breakwaters and shoreline edging in freshwater systems that can incorporate EWN benefits are summarized.

19 Sep 2024

Case Study of Continental-Scale Hydrologic Modeling’s Ability to Predict Daily Streamflow Percentiles for Regulatory Application

Abstract: Regulatory practitioners use hydroclimatic data to provide context to observations typically collected through field site visits and aerial imagery analysis. In the absence of site-specific data, regulatory practitioners must use proxy hydroclimatic data and models to assess a stream's hydroclimatology. One intent of current-generation continental-scale hydrologic models is to provide such hydrologic context to ungaged watersheds. In this study, the ability of two state-of-the-art, operational, continental-scale hydrologic modeling frameworks, the National Water Model and the Group on Earth Observation Global Water Sustainability (GEOGloWS) European Centre for Medium-Range Weather Forecasts (ECMWF) Streamflow Model, to produce daily streamflow percentiles and categorical estimates of the streamflow normalcy was examined. The modeled stream-flow percentiles were compared to observed daily streamflow percentiles at four United States Geological Survey stream gages. The model's performance was then compared to a baseline assessment methodology, the Antecedent Precipitation Tool. Results indicated that, when compared to baseline assessment techniques, the accuracy of the National Water Model (NWM) or GEOGloWS ECMWF Streamflow Model was greater than the accuracy of the baseline assessment methodology at four stream gage locations. The NWM performed best at three of the four gages. This work highlighted a novel application of current-generation continental-scale hydrologic models.

18 Sep 2024

Opportunities for Upper Mississippi River System Sand to Support Coastal Beach Nourishment

Abstract: This research presents an opportunity to review the concept, status, and cost of using Upper Mississippi River (UMR) riverine dredged sand to nourish coastal beaches for increased resilience. Several dredged placement sites, transport modes, commercial and industrial uses, and end-point destinations will be identified in regional assessments and several specific UMR sediment to Great Lakes beneficial use projects will be reviewed here and assessed in greater detail during this research investigation.

17 Sep 2024

Human Well-Being and Natural Infrastructure: Assessing Opportunities for Equitable Project Planning and Implementation

Abstract: There is consensus within psychological, physiological, medical, and social science disciplines that active and passive exposure to nature enhances human well-being. Natural infrastructure (NI) includes elements of nature that can deliver these ancillary well-being benefits while serving their infrastructure-related purposes and, as such, offer great promise for agencies including the U.S. Army Corps of Engineers as a means of enhancing economic, environmental, and societal benefits in civil works projects. Yet, to date, NI are typically framed as alternatives to conventional infrastructure but are rarely competitive for project selection because there is no standardized approach to demonstrate their value or justify their cost. The infrastructure projects subsequently selected may not maximize societal well-being or distribute benefits equitably. A framework is needed to capture diverse and holistic benefits of NI. As part of ongoing research, this paper describes the components necessary to construct a framework for well-being benefits accounting and equitable distribution of NI projects and explores how they might be applied within a framework. We conclude with methodological examples of well-being accounting tools for NI that are based on ongoing research and development associated with this project. The findings provide insights and support for both the Engineering with Nature community and the community of NI practitioners at large.

12 Sep 2024

Coherent Marine X-Band Radar Deployment during DUNEX

Abstract: A marine X-band radar system, developed by Helmholtz-Zentrum Hereon (Hereon) was deployed within view of the nearshore at the US Army Engineer Research and Development Center, Field Research Facility (FRF), in Duck, North Carolina, from October 2021 to August 2022. The radar deployment was a collaboration among researchers at the FRF, Hereon, and the University of Miami and was initiated as part of the During Nearshore Event Experiment (DUNEX), a large multi-institutional field experiment funded by the US Coastal Research Program. The Hereon radar successfully collected data during the main DUNEX field campaign (approximately October 2021) and continued to collect nearly continuously until August 2022. To facilitate use of Hereon radar data, this document describes the deployment, provides background and context, and presents metadata. Within, we describe in detail the Hereon radar system, the locations of two different installations, the time periods covered, sampling modes, environmental conditions and notable events, example data products, and potential pathways for future use of the data.

11 Sep 2024

Modifications to an Amphibious Unoccupied Ground Vehicle (AUGV) for Survey Operations

Abstract: Developing unoccupied systems capable of collecting data in the very shallow water (<10 m) and surfzone (typically <3 m) is a challenging task for many reasons including waves, sediment, bubbles, and turbulent velocities. This document focuses on describing some of the additions, enhancements, and refinements to a commercial-off-the-shelf (COTS) system, the SeaOx, available from Bayonet Ocean Vehicles (previously C2i). In addition, practical experience in using this platform to collect data in the surfzone is documented.

11 Sep 2024

Bathymetric Inversion from Unmanned Aircraft System (UAS) Video on Inland Waters, Port Huron, Michigan

Abstract: This Coastal and Hydraulics Engineering Technical Note (CHETN) presents a proof of concept for the use of the cBathy algorithm to estimate bathymetry in an inland water environment. The document summarizes the methods used in collecting and analyzing stationary UAS (unmanned aircraft system) video taken at the Fort Gratiot Lighthouse Park in Port Huron, Michigan, a shoreline overseen by the US Army Corps of Engineers (USACE), Detroit District (LRE). The results presented in this report show that the cBathy algorithm has the potential to measure bathymetry in areas of inland water with sufficient fetch to generate wind swell, similar to how cBathy has been used in open-coast nearshore environments.

11 Sep 2024

Evaluating Topographic Reconstruction Accuracy of Planet Lab’s Stereo Satellite Imagery

Abstract: The goal of this Coastal and Hydraulics Engineering Technical Note (CHETN) is to document initial results to derive topography on the beachface in the northern Outer Banks, North Carolina, utilizing Planet Labs’ SkySat stereo panchromatic imagery processed in Agisoft Metashape. This technical note will provide an initial evaluation into whether Planet Lab’s SkySat imagery is a suitable image source for satellite Structure from Motion (SfM) algorithms as well as whether these data should be explored as a federal beach project monitoring tool. Depending on required accuracy, these data have the potential to aid coastal scientists, managers, and US Army Corps of Engineers (USACE) engineers in understanding the now-state of their coastlines and employ cost-effective adaptive management techniques.