Engineering Commons^™

Recent Progress In Performance Evaluations And Near Real-Time Assessment Of Operational Ocean Products, Fabrice Hernandez, Edward Blockley, Gary B. Brassington, Fraser Davidson, Prasanth Divakaran, Marie Drévillon, Shiro Ishizaki, Marcos Garcia-Sotillo, Patrick J. Hogan, Priidik Lagemaa, Bruno Levier, Matthew Martin, Avichal Mehra, Christopher Mooers, Nicolas Ferry, Andrew Ryan, Charly Regnier, Alistair Sellar, Gregory C. Smith, Sarantis Sofianos, Todd Spindler, Gianluca Volpe, John Wilkin, Edward Zaron, Aijun Zhang

Civil and Environmental Engineering Faculty Publications and Presentations

Operational ocean forecast systems provide routine marine products to an ever-widening community of users and stakeholders. The majority of users need information about the quality and reliability of the products to exploit them fully. Hence, forecast centres have been developing improved methods for evaluating and communicating the quality of their products. Global Ocean Data Assimilation Experiment (GODAE) OceanView, along with the Copernicus European Marine Core Service and other national and international programmes, has facilitated the development of coordinated validation activities among these centres. New metrics, assessing a wider range of ocean parameters, have been defined and implemented in real-time. An …

Comparisons Of Linear Regression Models For Properties Of Alkaliactivated Binder Concrete, Arkamitra Kar, Udaya B. Halabe, Indrajit Ray, Avinash Unnikrishnan

Civil and Environmental Engineering Faculty Publications and Presentations

Concrete with alkali-activated binder (AAB) is increasingly considered as a better alternative to conventional portland cement (PC) concrete due to its superior sustainable and green properties. In order to promote the practical usage of AAB concrete, a previous study by the present authors proposed models on correlations among their mechanical and nondestructive properties. The present study extends the previous knowledge by proposing new improved models using linear regressions to predict compressive strengths and modulus of elasticity from ultrasonic pulse velocities. The models are developed for both unstressed and stressed AAB concrete with different curing temperatures. The accuracies of the models …

Development Of A Pedestrian Demand Estimation Tool, Kelly Clifton, Patrick Allen Singleton, Christopher D. Muhs, Robert J. Schneider

Civil and Environmental Engineering Faculty Publications and Presentations

Most research on walking behavior has focused on mode choice or walk-trip frequency. In contrast, this study is one of the first to analyze the destination choice behaviors of pedestrians. Using about 4,500 walk trips from a 2011 household travel survey in the Portland, OR, region, we estimated multinomial logit pedestrian destination choice models for six trip purposes. Independent variables included terms for impedance (walk-trip distance); size (employment by type, households); supportive pedestrian environments (parks, a pedestrian index of the environment variable called PIE); barriers to walking (terrain, industrial-type employment); and traveler characteristics. Unique to this study was the use …

Estimation Of Historic Flows And Sediment Loads To San Francisco Bay, 1849 – 2011, Hamed Moftakhari Rostamkhani, David A. Jay, Stefan A. Talke, David H. Schoellhamer

Civil and Environmental Engineering Faculty Publications and Presentations

River flow and sediment transport in estuaries influence morphological development over decadal and century time scales, but hydrological and sedimentological records are typically too short to adequately characterize long-term trends. In this study, we recover archival records and apply a rating curve approach to develop the first instrumental estimates of daily delta inflow and sediment loads to San Francisco Bay (1849 – 1929). The total sediment load is constrained using sedimentation/erosion estimated from bathymetric survey data to produce continuous daily sediment transport estimates from 1849 to 1955, the time period prior to sediment load measurements. We estimate that ~55% (45 …

Evaluating The Use Of Crowdsourcing As A Data Collection Method For Bicycle Performance Measures And Identification Of Facility Improvement Needs, Miguel A. Figliozzi, Bryan Philip Blanc

Civil and Environmental Engineering Faculty Publications and Presentations

This research developed a smartphone application called ORcycle to collect cyclists’ routes, users, and comfort levels. ORcycle combines GPS revealed route data collection with new questionnaires that try to elicit cyclists’ attitudes as well as comfort levels and factors that influence their perceived comfort and route choice. The new questionnaires were developed to better understand how cyclists’ comfort levels are affected by route characteristics, route stressors, safety reports, cyclists’ demographics, and cyclists’ cycling attitude. Preliminary results show that many trip characteristics, route choice factors, route stressors and demographic variables are correlated with comfort levels. ORcycle is the first statewide deployment …

Channel Shallowing As Mitigation Of Coastal Flooding, Philip M. Orton, Stefan A. Talke, David A. Jay, Larry Yin, Alan F. Blumberg, Nickitas Georgas, Haihong Zhao, Hugh J. Roberts, Kytt Macmanus

Civil and Environmental Engineering Faculty Publications and Presentations

Here, we demonstrate that reductions in the depth of inlets or estuary channels can be used to reduce or prevent coastal flooding. A validated hydrodynamic model of Jamaica Bay, New York City (NYC), is used to test nature-based adaptation measures in ameliorating flooding for NYC’s two largest historical coastal flood events. In addition to control runs with modern bathymetry, three altered landscape scenarios are tested: (1) increasing the area of wetlands to their 1879 footprint and bathymetry, but leaving deep shipping channels unaltered; (2) shallowing all areas deeper than 2 m in the bay to be 2 m below Mean …

Toward A Spatial-Temporal Measure Of Land-Use Mix, Steven R. Gehrke, Kelly Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

Urban planning and public-health research has long been interested in the connection between land-use mix and travel. Interest from urban planners stems from the potential of transportation efficiency gains achieved by an increased land-use mix and subsequent shortening of trip lengths; whereas, public-health research advocates an increased land-use mix as an effective policy for facilitating greater physical activity. Yet, despite the transportation, land-use, and health benefits related to improving land-use mix and the extent of topical attention given by researchers, no consensus has been reached regarding the magnitude of its effect on travel. This absence of agreement may largely be …

On The Assessment Of Reliability In Probabilistic Hydrometeorological Event Forecasting, Caleb Matthew Dechant, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

Probabilistic forecasts are commonly used to communicate uncertainty in the occurrence of hydrometeorological events. Although probabilistic forecasting is common, conventional methods for assessing the reliability of these forecasts are approximate. Among the most common methods for assessing reliability, the decomposed Brier Score and Reliability Diagram treat an observed string of events as samples from multiple Binomial distributions, but this is an approximation of the forecast reliability, leading to unnecessary loss of information. This article suggests testing the hypothesis of reliability via the Poisson-Binomial distribution, which is a generalized solution to the Binomial distribution, providing a more accurate model of the …

Development Of A Pedestrian Demand Estimation Tool: A Destination Choice Model, Christopher D. Muhs, Kelly Clifton, Patrick Allen Singleton, Robert J. Schneider

Civil and Environmental Engineering Faculty Publications and Presentations

There is growing support for improvements to the quality of the walking environment, including more investments to promote pedestrian travel. Planners, engineers, and others seek improved tools to estimate pedestrian demand that are sensitive to environmental and demographic factors at the appropriate scale in order to aid policy-relevant issues like air quality, public health, and smart allocation of infrastructure and other resources. Further, in the travel demand forecasting realm, tools of this kind are difficult to implement due to the use of spatial scales of analysis that are oriented towards motorized modes, vast data requirements, and computer processing limitations.

To …

Identification And Quantification Of Gaseous Organic Compounds Emitted From Biomass Burning Using Two-Dimensional Gas Chromatography–Time-Of-Flight Mass Spectrometry, Lindsay E. Hatch, Wentai Luo, James F. Pankow, Robert J. Yokelson, Chelsea E. Stockwell, Kelley Barsanti

Civil and Environmental Engineering Faculty Publications and Presentations

The current understanding of secondary organic aerosol (SOA) formation within biomass burning (BB) plumes is limited by the incomplete identification and quantification of the non-methane organic compounds (NMOCs) emitted from such fires. Gaseous organic compounds were collected on sorbent cartridges during laboratory burns as part of the fourth Fire Lab at Missoula Experiment (FLAME- 4) and analyzed by two-dimensional gas chromatography– time-of-flight mass spectrometry (GC × GC–ToFMS). The sensitivity and resolving power of GC × GC–ToFMS allowed the acquisition of the most extensive data set of BB NMOCs to date, with measurements for 708 positively or tentatively identified compounds. Estimated …

Modeling Regional Secondary Organic Aerosol Using The Master Chemical Mechanism, Jingyi Li, Meredith Cleveland, Luke D. Ziemba, Robert J. Griffin, Kelley Barsanti, James F. Pankow, Qi Ying

Civil and Environmental Engineering Faculty Publications and Presentations

A modified near-explicit Master Chemical Mechanism (MCM, version 3.2) with 5727 species and 16,930 reactions and an equilibrium partitioning module was incorporated into the Community Air Quality Model (CMAQ) to predict the regional concentrations of secondary organic aerosol (SOA) from volatile organic compounds (VOCs) in the eastern United States (US). In addition to the semi-volatile SOA from equilibrium partitioning, reactive surface uptake processes were used to simulate SOA formation due to isoprene epoxydiol, glyoxal and methylglyoxal. The CMAQ-MCM-SOA model was applied to simulate SOA formation during a two-week episode from August 28 to September 7, 2006. The southeastern US has …

Roadway Determinants Of Bicyclist Multi-Pollutant Exposure Concentrations, Alexander Y. Bigazzi, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Due to poorly quantified traffic-exposure relationships, transportation professionals are unable to easily estimate exposure differences among bicycle routes for network planning, design, and analysis. This paper estimates the effects of roadway characteristics on bicyclist multi-pollutant exposure concentrations, controlling for meteorology and background conditions. Concentrations of volatile organic compounds (VOC), carbon monoxide (CO), and fine particulate matter (PM2.5) are modeled using high-resolution on-road data. This paper also compares exposure differences on immediately parallel high-traffic/low-traffic facilities and is the first study to quantify VOC exposure differences by facility. Results indicate that average daily traffic (ADT) provides a parsimonious way to characterize the …

Empirical Analysis Of Bus Bunching Characteristics Based On Bus Avl/Apc Data, Wei Feng, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Bus bunching takes place when headways between buses are irregular. Bus bunching is associated with longer waiting times for riders, overcrowding in some buses, and an overall decrease on the level of service and capacity. Understanding the temporal and spatial characteristics and the causes and effects of bus bunching incidents from archived bus data can greatly aid transit agencies to develop efficient mitigation strategies. This paper presents methods to identify and visualize specific time periods and segments where bus bunching incidents occur based on automatic vehicle location (AVL) and automatic passenger count (APC) data. The paper also proposes methods that …

Exploring Thresholds For Timing Strategies On A Pedestrian Active Corridor, Sirisha Murthy Kothuri, Peter Koonce, Christopher M. Monsere, Titus Reynolds

Civil and Environmental Engineering Faculty Publications and Presentations

Traditional signal timing policies have typically prioritized vehicles over pedestrians at intersections, leading to undesirable consequences such as large delays and risky crossing behaviors. The objective of this paper is to explore signal timing control strategies to reduce pedestrian delay at signalized intersections. The impacts of change in signal controller mode of operation (coordinated vs. free) at intersections were studied using the micro-simulation software VISSIM. A base model was developed and calibrated for an existing pedestrian active corridor. A hypothetical network of three intersections was used to explore the effects of mode of operation and measures of delay for pedestrians …

The Skill Of Seasonal Ensemble Low-Flow Forecasts In The Moselle River For Three Different Hydrological Models, Mehmet C. Demirel, Martijn Booij, Arjen Hoekstra

Civil and Environmental Engineering Faculty Publications and Presentations

This paper investigates the skill of 90-day low-flow forecasts using two conceptual hydrological models and one data-driven model based on Artificial Neural Networks (ANNs) for the Moselle River. The three models, i.e. HBV, GR4J and ANN-Ensemble (ANN-E), all use forecasted meteorological inputs (precipitation P and potential evapotranspiration PET), whereby we employ ensemble seasonal meteorological forecasts. We compared low-flow forecasts for five different cases of seasonal meteorological forcing: (1) ensemble P and PET forecasts; (2) ensemble P forecasts and observed climate mean PET; (3) observed climate mean P and ensemble PET forecasts; (4) observed climate mean P and PET and (5) …

A Level-Of-Service Model For Protected Bike Lanes, Nick Foster, Christopher Monsere, Jennifer Dill, Kelly Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

Several methods exist for quantifying the quality of service provided by a roadway from a bicyclist’s perspective; however, many of these models do not consider physically protected bike lanes and, of those that do, none is based on empirical data from the US. This is problematic as engineers, planners, and elected officials are increasingly looking to objective performance measures to help guide transportation project design and funding prioritization decisions. This paper addresses this gap by presenting a cumulative logistic model to predict user comfort on protected bike lanes developed from data collected during in-person video surveys. The surveys were conducted …

Does The Bicycle Detector Symbol Change Cyclist Queuing Position At Signalized Intersections?, Stefan W. Bussey, Christopher M. Monsere, Peter Koonce

Civil and Environmental Engineering Faculty Publications and Presentations

The Manual of Traffic Control Devices (MUTCD) includes a bicycle detector pavement marking (Section 9C-05) and accompanying explanatory sign (R10-22) which may encourage cyclists to position themselves over detection at traffic signals. This paper presents the results of an observational and survey- based study evaluating the bicycle detector marking. Three minor actuated approaches at signalized intersections with significant bicycle volumes and without bicycle detector markings were selected for treatment. Three configurations were compared: 1) bicycle detector marking only 2) bicycle detector marking with the R10-22 explanatory sign, and 3) an alternative bicycle detector installed over a contrasting green rectangle. Analysis …

Dynamic Ventilation And Power Output Of Urban Bicyclists, Alexander Y. Bigazzi, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Bicyclist intake of air pollutants is linked to physical exertion levels, ventilation rates, and exposure concentrations. Whereas exposure concentrations have been widely studied in transportation environments, there is relatively scant research linking on-road ventilation with travel conditions and exertion levels. This paper investigates relationships among power output, heart rate, and ventilation rate for urban bicyclists. Heart rate and ventilation rate were measured on-road and combined with power output estimates from a bicycle power model. Dynamic ventilation rates increased by 0.4-0.8% per watt of power output, with a mean lag of 0.8 minutes. The use of physiology (ventilation) monitoring straps and …

Adjusting Ite’S Trip Generation Handbook For Urban Context, Kelly J. Clifton, Kristina Marie Currans, Christopher D. Muhs

Civil and Environmental Engineering Faculty Publications and Presentations

This study examines the ways in which urban context affects vehicle trip generation rates across three land uses. An intercept travel survey was administered at 78 establishments (high-turnover restaurants, convenience markets, and drinking places) in the Portland, Oregon, region during 2011. This approach was developed to adjust the Institute of Transportation Engineers (ITE) Trip Generation Handbook vehicle trip rates based on built environment characteristics where the establishments were located. A number of policy-relevant built environment measures were used to estimate a set of nine models predicting an adjustment to ITE trip rates. Each model was estimated as a single measure: …

Tides And The Swot Mission: Transition From Science Definition Team To Science Team, Brian K. Arbic, Florent Lyard, Aurelien Ponte, Richard D. Ray, James G. Richman, Jay F. Shriver, Edward Zaron, Zhongxiang Zhao

Civil and Environmental Engineering Faculty Publications and Presentations

As the SWOT wide-swath satellite altimeter mission transitions from the Science Definition Team to the Science Team, it is an opportune time to review the progress that has been made with respect to tides, and the work remaining to be done. As with previous altimeter missions, tides present both an opportunity and a challenge for the SWOT mission. The TOPEX/Jason class of altimeters have allowed high-accuracy mapping of open-ocean barotropic tides over their coverage latitudes (66°S to 66°N), but the inter-track spacing of these missions (~150 km) has limited their ability to map smaller-scale features such as shelf tides, coastal …

Sensitivity Of Columbia Basin Runoff To Long-Term Changes In Multi-Model Cmip5 Precipitation Simulations, Mehmet Demirel, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

In this study, we used precipitation elasticity index of streamflow, to reflect on the sensitivity of streamflow to changes in future precipitation. We estimated precipitation elasticity of streamflow from: (1) simulated streamflow by the VIC model using observed precipitation for the current climate (1963–2003); (2) simulated streamflow by the VIC model using simulated precipitation from 10 GCM - CMIP5 dataset for the future climate (2010–2099) including two different pathways (RCP4.5 and RCP8.5) and two different downscaled products (BCSD and MACA). The hydrological model was calibrated at 1/16 latitude-longitude resolution and the simulated streamflow was routed to the subbasin outlets of …

The Effect Of Multi-Model Averaging Of Climate Model Outputs On The Seasonality Of Rainfall Over The Columbia River Basin, Mehmet Demirel, Arun Rana, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

The rainfall seasonality index is the measure of precipitation distribution throughout the seasonal cycle. The aim of this study is to compare the effect of different multi-model averaging methods on the rainfall seasonality index at each 1/16 latitude-longitude cells covering the Columbia River Basin. In accordance with the same, ten different climate model outputs are selected from 45 available climate models from CMIP5 dataset. The reanalysis precipitation data is used to estimate the errors in rainfall seasonality for the climate model outputs. The inverse variance method and statistical multi criteria analysis (SMCA) method were used to estimate the weights for …

Impacts Of Climate Change On The Seasonality Of Extremes In The Columbia River Basin, Mehmet Demirel, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

The impacts of climate change on the seasonality of extremes i.e. both high and low flows in the Columbia River basin were analyzed using three seasonality indices, namely the seasonality ratio (SR), weighted mean occurrence day (WMOD) and weighted persistence (WP). These indices reflect the streamflow regime, timing and variability in timing of extreme events respectively. The three indices were estimated from: (1) observed streamflow; (2) simulated streamflow by the VIC model using simulated inputs from ten combinations of bias corrected and downscaled CMIP5 inputs for the current climate (1979–2005); (3) simulated streamflow using simulated inputs from ten combinations of …

Can Tidal Perturbations Associated With Sea Level Variations In The Western Pacific Ocean Be Used To Understand Future Effects Of Tidal Evolution?, Adam T. Devlin, David A. Jay, Stefan A. Talke, Edward D. Zaron

Civil and Environmental Engineering Faculty Publications and Presentations

This study examines connections between mean sea level (MSL) variability and diurnal and semidiurnal tidal constituent variations at 17 open-ocean and 9 continental shelf tide gauges in the western tropical Pacific Ocean, a region showing anomalous rise in MSL over the last 20 years and strong interannual variability. Detrended MSL fluctuations are correlated with detrended tidal amplitude and phase fluctuations, defined as tidal anomaly trends (TATs), to quantify the response of tidal properties to MSL variation. About 20 significant amplitude and phase TATs are found for each of the two strongest tidal constituents, K₁ (diurnal) and M₂ (semidiurnal). …

Modeling And Analyzing The Impact Of Advanced Technologies On Transit Performance Measures In Arterial Corridors, Miguel A. Figliozzi, Wei Feng

Civil and Environmental Engineering Faculty Publications and Presentations

Transportation and transit agencies have implemented advanced technologies like transit signal priority (TSP) and Sydney Coordinated Adaptive Traffic System (SCATS) to reduce travel times and improve reliability. However, due to the lack of detailed empirical data, the joint impact of these factors and improvement strategies on bus travel time has not been studied at the stop-to-stop segment level. With the aim of assessing the performance of an existing TSP/SCATS system, this study had access to a unique set of high-resolution bus and traffic signal data. Novel algorithms and performance measures to measure TSP performance are proposed. Results indicate that a …

An Analysis Of Secular Change In Tides At Open-Ocean Sites In The Pacific, Edward D. Zaron, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

Hourly sea level is examined at 25 open-ocean stations in the Pacific Ocean with records longer than 30 yr. A search for trends finds that the amplitude of the dominant semidiurnal tide M₂ is increasing at 12 of the 13 sites where a statistically significant trend can be identified. It is also found that nontidal variance in the neighborhood of M₂ is decreasing at all 12 of the sites where a significant increase in M₂ tide is occurring. The trend in amplitude of the dominant diurnal tide K₁ is significant at six stations, and it is …

Lessons From The Green Lanes: Evaluating Protected Bike Lanes In The U.S., Christopher Monsere, Jennifer Dill, Nathan Mcneil, Kelly J. Clifton, Nick Foster, Tara Goddard, Mathew Berkow, Joe Gilpin, Kim Voros, Drusilla Van Hengel, Jamie Parks

Civil and Environmental Engineering Faculty Publications and Presentations

This report presents finding from research evaluating U.S. protected bicycle lanes (cycle tracks) in terms of their use, perception, benefits, and impacts. This research examines protected bicycle lanes in five cities: Austin, TX; Chicago, IL; Portland, OR; San Francisco, CA; and Washington, D.C., using video, surveys of intercepted bicyclists and nearby residents, and count data. A total of 168 hours were analyzed in this report where 16,393 bicyclists and 19,724 turning and merging vehicles were observed. These data were analyzed to assess actual behavior of bicyclists and motor vehicle drivers to determine how well each user type understands the design …

Increasing Storm Tides In New York Harbor, 1844–2013, Stefan A. Talke, Philip M. Orton, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

Three of the nine highest recorded water levels in the New York Harbor region have occurred since 2010 (March 2010, August 2011, and October 2012), and eight of the largest twenty have occurred since 1990. To investigate whether this cluster of high waters is a random occurrence or indicative of intensified storm tides, we recover archival tide gauge data back to 1844 and evaluate the trajectory of the annual maximum storm tide. Approximately half of long-term variance is anticorrelated with decadal-scale variations in the North Atlantic Oscillation, while long-term trends explain the remainder. The 10 year storm tide has increased …

Time-Variable Refraction Of The Internal Tide At The Hawaiian Ridge, Edward D. Zaron, Gary D. Egbert

Civil and Environmental Engineering Faculty Publications and Presentations

The interaction of the dominant semidiurnal M₂ internal tide with the large-scale subtidal flow is examined in an ocean model by propagating the tide through an ensemble of background fields in a domain centered on the Hawaiian Ridge. The background fields are taken from the Simple Ocean Data Assimilation (SODA) ocean analysis, at 2-month intervals from 1992 through 2001. Tides are computed with the Primitive Equation Z-coordinate Harmonic Analysis of Tides (PEZ-HAT) model by 14-day integrations using SODA initial conditions and M2 tidal forcing. Variability of the tide is found to occur primarily as the result of propagation through …

Wider Dissemination Of Household Travel Survey Data Using Geographical Perturbation Methods, Kelly J. Clifton, Steven R. Gehrke

Civil and Environmental Engineering Faculty Publications and Presentations

Public agencies spend vast amounts of money collecting information about passenger travel in household travel surveys. These data are valuable for the rich and detailed information they provide, which contribute to regional and statewide travel demand models. These data have utility beyond travel demand modeling in their application to transportation policy and travel behavior research. As the demand on these data increase, so have the quantity of information collected. Detailed geospatial referencing of the home, work and other travel destinations are common practice and permit the integration with other spatially archived data sources, such as land use characteristics, transportation system …