14 May 2021

Metrics for Assessing Overall Performance of Inland Waterway Ports: A Bayesian Network Based Approach

Abstract: Because ports are considered to be the heart of the maritime transportation system, thereby assessing port performance is necessary for a nation’s development and economic success. This study proposes a novel metric, namely, “port performance index (PPI)”, to determine the overall performance and utilization of inland waterway ports based on six criteria, port facility, port availability, port economics, port service, port connectivity, and port environment. Unlike existing literature, which mainly ranks ports based on quantitative factors, this study utilizes a Bayesian Network (BN) model that focuses on both quantitative and qualitative factors to rank a port. The assessment of inland waterway port performance is further analyzed based on different advanced techniques such as sensitivity analysis and belief propagation. Insights drawn from the study show that all the six criteria are necessary to predict PPI. The study also showed that port service has the highest impact while port economics has the lowest impact among the six criteria on PPI for inland waterway ports.

14 May 2021

State of the Practice in Pavement Structural Design/Analysis Codes Relevant to Airfield Pavement Design

Abstract: An airfield pavement structure is designed to support aircraft live loads for a specified pavement design life. Computer codes are available to assist the engineer in designing an airfield pavement structure. Pavement structural design is generally a function of five criteria: the pavement structural configuration, materials, the applied loading, ambient conditions, and how pavement failure is defined. The two typical types of pavement structures, rigid and flexible, provide load support in fundamentally different ways and develop different stress distributions at the pavement – base interface. Airfield pavement structural design is unique due to the large concentrated dynamic loads that a pavement structure endures to support aircraft movements. Aircraft live loads that accompany aircraft movements are characterized in terms of the load magnitude, load area (tire-pavement contact surface), aircraft speed, movement frequency, landing gear configuration, and wheel coverage. The typical methods used for pavement structural design can be categorized into three approaches: empirical methods, analytical (closed-form) solutions, and numerical (finite element analysis) approaches. This article examines computational approaches used for airfield pavement structural design to summarize the state-of-the-practice and to identify opportunities for future advancements. United States and non-U.S. airfield pavement structural codes are reviewed in this article considering their computational methodology and intrinsic qualities.

14 May 2021

Hydraulic Dike Effects Investigation on the Mississippi River: Natchez to Baton Rouge

Abstract: This report documents an investigation of the hydraulic effects of dikes on water levels in the Mississippi River between Natchez, MS, and Baton Rouge, LA, conducted for the U.S. Army Corps of Engineers, Mississippi Valley Division, Vicksburg, MS. The investigation was conducted using a previously calibrated Natchez-to-Baton Rouge Adaptive Hydraulics numerical model. The objectives were to alter roughness and height variables associated with the dikes and overbanks encompassed in the numerical model and evaluate their effects on water surface elevations. Steady flow simulations were simulated for 12 May 2011 to investigate the variation in model results during the peak of the 2011 flood on the Mississippi River.

14 May 2021

In Situ and Post-Processing Volume Rendering with Cinema

Abstract: We present a new batch volume rendering technique which alleviates the time and expertise needed by the domain scientist in order to produce quality volume rendered results. This process can be done both in situ and as a post-processing step. The advantage of performing this as an in situ process is that the user is not required to have a priori knowledge of the exact physics and how best to create a transfer function to volume render that physics during the in situ run. For the post-processing use case, the user has the ability to easily examine a wide variety of transfer functions without the tedious work of manually generating each one.

14 May 2021

Scale Invariance of Albedo-Based Wind Friction Velocity

Abstract: Obtaining reliable estimates of aerodynamic roughness is necessary to interpret and accurately predict aeolian sediment transport dynamics. However, inherent uncertainties in field measurements and models of surface aerodynamic properties continue to undermine aeolian research, monitoring, and dust modeling. A new relation between aerodynamic shelter and land surface shadow has been established at the wind tunnel scale, enabling the potential for estimates of wind erosion and dust emission to be obtained across scales from albedo data. Here, we compare estimates of wind friction velocity (u*) derived from traditional methods (wind speed profiles) with those derived from the albedo model at two separate scales using bare soil patch (via net radiometers) and landscape (via MODIS 500 m) datasets. Results show that profile-derived estimates of u* are highly variable in anisotropic surface roughness due to changes in wind direction and fetch. Wind speed profiles poorly estimate soil surface (bed) wind friction velocities necessary for aeolian sediment transport research and modeling. Albedo-based estimates of u* at both scales have small variability because the estimate is integrated over a defined, fixed area and resolves the partition of wind momentum between roughness elements and the soil surface. We demonstrate that the wind tunnel-based calibration of albedo for predicting wind friction velocities at the soil surface (us*) is applicable across scales. The albedo-based approach enables consistent and reliable drag partition correction across scales for model and field estimates of us* necessary for wind erosion and dust emission modeling.

12 May 2021

Application of Incremental Sampling Methodology for Subsurface Sampling

ABSTRACT:  Historically, researchers studying contaminated sites have used grab sampling to collect soil samples. However, this methodology can introduce error in the analysis because it does not account for the wide variations of contaminant concentrations in soil. An alternative method is the Incremental Sampling Methodology (ISM), which previous studies have shown more accurately captures the true concentration of contaminants over an area, even in heterogeneous soils. This report describes the methods and materials used with ISM to collect soil samples, specifically for the purpose of mapping subsurface contamination from site activities. The field data presented indicates that ISM is a promising methodology for collecting subsurface soil samples containing contaminants of concern, including metals and semivolatile organic compounds (SVOCs), for analysis. Ultimately, this study found ISM to be useful for supplying information to assist in the decisions needed for remediation activities.

12 May 2021

Wintertime Snow and Precipitation Conditions in the Willow Creek Watershed above Ririe Dam, Idaho

ABSTRACT:  The Ririe Dam and Reservoir project is located on Willow Creek near Idaho Falls, Idaho, and is important for flood risk reduction and water supply. The current operating criteria is based on fully storing a large winter runoff event. These winter runoff events are generally from large storm events, termed atmospheric rivers, which produce substantial precipitation. In addition to the precipitation, enhanced runoff is produced due to frozen soil and snowmelt. However, the need for additional water supply by local stakeholders has prompted the U.S. Army Corps of Engineers to seek to better understand the current level of flood risk reduction provided by Ririe Dam and Reservoir.  Flood risk analysis using hydrologic modeling software requires quantification of the probability for all of the hydrometeorologic inputs. Our study develops the precipitation, SWE, and frozen ground probabilities that are required for the hydrologic modeling necessary to quantify the current winter flood risk.

12 May 2021

Development of CORPS-STIF 1.0 with Application to Ultra-High Performance Concrete (UHPC)

Abstract: This report introduces the first release of CORPS-STIF (Concrete Observations Repository and Predictive Software – Structural and Thermodynamical Integrated Framework). CORPS-STIF is envisioned to be used as a tool to optimize material constituents and geometries of mass concrete placements specifically for ultra-high performance concretes (UHPCs). An observations repository (OR) containing results of 649 mechanical property tests and 10 thermodynamical tests were recorded to be used as inputs for current and future releases. A thermodynamical integrated framework (TIF) was developed where the heat transfer coefficient was a function of temperature and determined at each time step. A structural integrated framework (SIF) modeled strength development in cylinders that underwent isothermal curing. CORPS-STIF represents a step toward understanding and predicting strength gain of UHPC for full-scale structures and specifically in mass concrete.

12 May 2021

Automated Characterization of Ridge-Swale Patterns Along the Mississippi River

Abstract: The orientation of constructed levee embankments relative to alluvial swales is a useful measure for identifying regions susceptible to backward erosion piping (BEP). This research was conducted to create an automated, efficient process to classify patterns and orientations of swales within the Lower Mississippi Valley (LMV) to support levee risk assessments. Two machine learning algorithms are used to train the classification models: a convolutional neural network and a U-net. The resulting workflow can identify linear topographic features but is unable to reliably differentiate swales from other features, such as the levee structure and riverbanks. Further tuning of training data or manual identification of regions of interest could yield significantly better results. The workflow also provides an orientation to each linear feature to support subsequent analyses of position relative to levee alignments. While the individual models fall short of immediate applicability, the procedure provides a feasible, automated scheme to assist in swale classification and characterization within mature alluvial valley systems similar to LMV.

12 May 2021

The Demonstration and Validation of a Linked Watershed-Riverine Modeling System for DoD Installations: User Guidance Report Version 2.0

Abstract: A linked watershed model was evaluated on three watersheds within the U.S.: (1) House Creek Watershed, Fort Hood, TX; (2) Calleguas Creek Watershed, Ventura County, CA; and (3) Patuxent River Watershed, MD. The goal of this demonstration study was to show the utility of such a model in addressing water quality issues facing DoD installations across a variety of climate zones. In performing the demonstration study, evaluations of model output with regards to accuracy, predictability and meeting regulatory drivers were completed. Data availability, level of modeling expertise, and costs for model setup, validation, scenario analysis, and maintenance were evaluated in order to inform installation managers on the time and cost investment needed to use a linked watershed modeling system. Final conclusions were that the system evaluated in this study would be useful for answering a variety of questions posed by installation managers and could be useful in developing management scenarios to better control pollutant runoff from installations.