Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
-
- Streamflow -- Forecasting (5)
- Tides (4)
- Hydrologic models (3)
- Uncertainty -- Mathematical models (3)
- Bayesian statistical decision theory (2)
-
- Air -- Pollution -- Health aspects -- Oregon -- Portland (1)
- Atmospheric aerosols -- Mathematical models (1)
- Automatic data collection systems (1)
- Automobiles -- Motors -- Exhaust gas -- Health aspects -- Oregon -- Portland (1)
- Bicycle commuting -- United States (1)
- Columbia River Estuary (Or. and Wash.) (1)
- Commuting -- Oregon (1)
- Cycling -- Oregon (1)
- Cycling -- Route choice (1)
- Cyclists -- Health and hygiene -- Oregon -- Portland (1)
- Energy transfer (1)
- Harmonic analysis (1)
- Household surveys (1)
- Hydrocarbons (1)
- Hydrologic models -- Data processing (1)
- Hydrology -- Data processing (1)
- Intelligent transportation systems (1)
- Intertidal ecology -- Pacific Ocean (1)
- Nitrates -- Environmental aspects (1)
- North Atlantic Ocean -- Climate (1)
- North Atlantic oscillation -- Environmental aspects (1)
- Oceanography (1)
- Oceanography -- Columbia River Estuary (Or. and Wash.) -- Mathematical models (1)
- Pedestrians -- Oregon (1)
- Perturbation (Mathematics) (1)
Articles 1 - 16 of 16
Full-Text Articles in Engineering
Sensitivity Of Columbia Basin Runoff To Long-Term Changes In Multi-Model Cmip5 Precipitation Simulations, Mehmet Demirel, Hamid Moradkhani
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 …
Improved Bayesian Multi-Modeling: Integration Of Copulas And Bayesian Model Averaging, Shahrbanou Madadgar, Hamid Moradkhani
Improved Bayesian Multi-Modeling: Integration Of Copulas And Bayesian Model Averaging, Shahrbanou Madadgar, Hamid Moradkhani
Civil and Environmental Engineering Faculty Publications and Presentations
Bayesian Model Averaging (BMA) is a popular approach to combine hydrologic forecasts from individual models, and characterize the uncertainty induced by model structure. In the original form of BMA, the conditional probability density function (PDF) of each model is assumed to be a particular probability distribution (e.g. Gaussian, gamma, etc.). If the predictions of any hydrologic model do not follow certain distribution, a data transformation procedure is required prior to model averaging. Moreover, it is strongly recommended to apply BMA on unbiased forecasts, whereas it is sometimes difficult to effectively remove bias from the predictions of complex hydrologic models. To …
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
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 …
Secondary Organic Aerosol Formation And Organic Nitrate Yield From No3 Oxidation Of Biogenic Hydrocarbons, Juliane L. Fry, Danielle C. Draper, Kelley C. Barsanti, James N. Smith, John Ortega, Paul M. Winkler, Michael J. Lawler, Steven S. Brown, Peter M. Edwards, Ronald C. Cohen, Lance Lee
Secondary Organic Aerosol Formation And Organic Nitrate Yield From No3 Oxidation Of Biogenic Hydrocarbons, Juliane L. Fry, Danielle C. Draper, Kelley C. Barsanti, James N. Smith, John Ortega, Paul M. Winkler, Michael J. Lawler, Steven S. Brown, Peter M. Edwards, Ronald C. Cohen, Lance Lee
Civil and Environmental Engineering Faculty Publications and Presentations
The secondary organic aerosol (SOA) mass yields from NO3 oxidation of a series of biogenic volatile organic compounds (BVOCs), consisting of five monoterpenes and one sesquiterpene (α-pinene, β-pinene, Δ-3-carene, limonene, sabinene, and β-caryophyllene), were investigated in a series of continuous flow experiments in a 10 m3 indoor Teflon chamber. By making in situ measurements of the nitrate radical and employing a kinetics box model, we generate time-dependent yield curves as a function of reacted BVOC. SOA yields varied dramatically among the different BVOCs, from zero for α-pinene to 38−65% for Δ-3-carene and 86% for β-caryophyllene at mass loading of 10 …
Impacts Of Climate Change On The Seasonality Of Extremes In The Columbia River Basin, Mehmet Demirel, Hamid Moradkhani
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 …
Modeling And Analyzing The Impact Of Advanced Technologies On Transit Performance Measures In Arterial Corridors, Miguel A. Figliozzi, Wei Feng
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 …
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
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). …
An Analysis Of Secular Change In Tides At Open-Ocean Sites In The Pacific, Edward D. Zaron, David A. Jay
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 …
Toward A Reliable Prediction Of Seasonal Forecast Uncertainty: Addressing Model And Initial Condition Uncertainty With Ensemble Data Assimilation And Sequential Bayesian Combination, Caleb Matthew Dechant, Hamid Moradkhani
Toward A Reliable Prediction Of Seasonal Forecast Uncertainty: Addressing Model And Initial Condition Uncertainty With Ensemble Data Assimilation And Sequential Bayesian Combination, Caleb Matthew Dechant, Hamid Moradkhani
Civil and Environmental Engineering Faculty Publications and Presentations
Uncertainties are an unfortunate yet inevitable part of any forecasting system. Within the context of seasonal hydrologic predictions, these uncertainties can be attributed to three causes: imperfect characterization of initial conditions, an incomplete knowledge of future climate and errors within computational models. This study proposes a method to account for all threes sources of uncertainty, providing a framework to reduce uncertainty and accurately convey persistent predictive uncertainty. In currently available forecast products, only a partial accounting of uncertainty is performed, with the focus primarily on meteorological forcing. For example, the Ensemble Streamflow Prediction (ESP) technique uses meteorological climatology to estimate …
Design And Implementation Of Pedestrian And Bicycle-Specific Data Collection Methods In Oregon, Miguel Figliozzi, Christopher Monsere, Krista Nordback, Pamela Johnson, Bryan Philip Blanc
Design And Implementation Of Pedestrian And Bicycle-Specific Data Collection Methods In Oregon, Miguel Figliozzi, Christopher Monsere, Krista Nordback, Pamela Johnson, Bryan Philip Blanc
Civil and Environmental Engineering Faculty Publications and Presentations
Although there is a growing need to access accurate and reliable pedestrian and bicycle data, there is no statewide system to collect data or plan future data collection efforts in the state of Oregon. To address these issues this research conducted a comprehensive review of pedestrian and bicycle data collection methods and counting technologies. Oregon data sources were also compiled and AADT estimation techniques were reviewed and applied to Oregon data. A pilot study was conducted to test bicycle and pedestrian counting methods at signalized intersections with 2070 controllers. The report also provides a summary of recommendations regarding factoring methods …
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
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
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 …
Modeling Historic Columbia River Flood Impacts, Lumas Helaire, Andrew Mahedy, Stefan A. Talke, David A. Jay
Modeling Historic Columbia River Flood Impacts, Lumas Helaire, Andrew Mahedy, Stefan A. Talke, David A. Jay
Civil and Environmental Engineering Faculty Publications and Presentations
The Lower Columbia River Estuary (LCRE) has undergone extensive modifications since the 19th century. Construction of dams, installation of jetties and dikes, dredging of the navigation channel and filling in of tidal wetlands have all contributed significantly to alterations in tidal dynamics and the flow regime, with consequences for habitat inundation and salinity intrusion. In this talk we discuss the development and implementation of a 19th century flow model for the LCRE, using a digital elevation model based on historic bathymetry. The model has been calibrated with recently rediscovered and digitized tide data from the 19th century. …
Bicycle Facilities And The Uptake Of Air Pollution By Active Travelers, Alexander Y. Bigazzi, Miguel A. Figliozzi, James F. Pankow, Wentai Luo, Lorne M. Isabelle
Bicycle Facilities And The Uptake Of Air Pollution By Active Travelers, Alexander Y. Bigazzi, Miguel A. Figliozzi, James F. Pankow, Wentai Luo, Lorne M. Isabelle
Civil and Environmental Engineering Faculty Publications and Presentations
Outlines the research of urban bicyclists' facilities and the uptake of air pollution by active travelers in urban Portland, OR. Outlines the research goals, beginning data collection methods, intake/uptake, modeling results, conclusions and the next steps for future work with the collected data set of direct uptake measurements.
Time-Variable Refraction Of The Internal Tide At The Hawaiian Ridge, Edward D. Zaron, Gary D. Egbert
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
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 …