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.

11 Sep 2024

Coastal Hazards System–South Atlantic (CHS-SA)

Abstract: The US Army Corps of Engineers completed the South Atlantic Coastal Study (SACS) to quantify storm surge and wave hazards, allowing for the expansion of the Coastal Hazards System (CHS) to the South Atlantic Division (SAD) domain. The goal of CHS-SACS was to quantify storm hazards for present conditions and future sea level rise scenarios to reduce flooding risk and increase resiliency in coastal environments. CHS-SACS was completed for three regions within the SAD domain, and this report focuses on the South Atlantic (CHS-SA). This study applied the CHS’ Probabilistic Framework with Joint Probability Method Augmented by Metamodeling Prediction (JPM-AMP) to perform a probabilistic coastal hazard analysis (PCHA) of tropical cyclone (TC) and extratropical cyclone (XC) responses, leveraging new atmospheric and hydrodynamic numerical model simulations of synthetic TCs and historical XCs. This report documents the CHS probabilistic framework to perform the PCHA for CHS-SA by executing the JPM-AMP, including storm climate characterization, storm sampling, storm recurrence rate estimation, marginal distributions, correlation and dependence structures of TC atmospheric-forcing parameters, development of augmented storm suites, and assignment of discrete storm weights to the synthetic TCs. Coastal hazards were estimated for annual exceedance frequencies over the range of 10 yr−1 to 10−4 yr−1.

11 Sep 2024

New Metrics for Managing Waterways: Vessel Encroachment Volume for Selected South Atlantic Division Ports

Abstract: The US Army Corps of Engineers (USACE) uses two metrics to evaluate maintenance for coastal navigation projects: cargo tonnage at the associated port and the controlling depth in the channel relative to the authorized channel depth. These are calculated through normal business practices and describe the relative importance (tonnage) of the port and the operating condition (controlling depth) of the channel. They are incorporated into a risk-based decision framework that directs funds to locations where channel conditions have deteriorated. Using Automatic Identification System (AIS) vessel-position data, USACE is pioneering the computation of metrics related to the space between the hull of transiting vessels and the waterway bed for channels, the underkeel clearance. This and related metrics describe how waterway users take advantage of the service provided directly by USACE (maintained channel depth). This study compares the underkeel clearance metrics among 13 ports in the South Atlantic Division over a span of 3 years by combining marine vessel AIS data, tidal predictions, channel bathymetric surveys, and vessel sailing draft. Comparing these values across ports allows these metrics to be integrated into the decision framework that drives dredge funding allocations.v

6 Sep 2024

Use of Chirp Sub-Bottom Acoustics to Assess Integrity of Water-Control Structures: Inner Harbor Navigation Canal Lock, New Orleans

Abstract: The US Army Corps of Engineers (USACE)-maintained lock on the Inner Harbor Navigation Canal serves as a critical navigation link between Lake Pontchartrain to the north and the Mississippi River to the south. Extensive slumping has been observed on the earthen embankment on each side of the lock, suggesting that internal pathways for water to escape through the lock’s concrete walls or joints are present. Unfortunately, traditional methods often used to identify cracks in the concrete (e.g., sidescan sonar) or water-filled voids under or behind the structure (e.g., ground-penetrating radar) did not identify any structural issues at this site. Prior to dewatering and repair, the USACE New Orleans District requested that the US Army Engineer Research and Development Center conduct a sub-bottom survey at the lock in order to identify water-filled voids and better prepare for potential repairs during dewatering. A unique sled was constructed that allowed a small vessel to tow the sub-bottom profiler at an angle to direct more acoustic energy into the structure. Low frequency, chirp acoustic energy successfully penetrated the concrete walls and identified several water-filled voids on both sides of the lock. A later post-dewatering walk-through indicated that the chirp imaged voids spatially adjacent to cracks, and cracks were not found in any other locations. Additional work is needed to further develop this methodology in other USACE structures.