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Full-Text Articles in Engineering

Spatial Transferability Assessment Of A Composite Walkability Index: The Pedestrian Index Of The Environment (Pie), Gabriel Lefebvre-Ropars, Catherine Morency, Patrick A. Singleton, Kelly J. Clifton Dec 2017

Spatial Transferability Assessment Of A Composite Walkability Index: The Pedestrian Index Of The Environment (Pie), Gabriel Lefebvre-Ropars, Catherine Morency, Patrick A. Singleton, Kelly J. Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

This paper analyzes the transferability of a composite walkability index, the Pedestrian Index of the Environment (PIE), to the Greater Montréal Area (GMA). The PIE was developed in Portland, Oregon, and is based on proprietary data. It combines six urban form variables into a score ranging from 20 to 100. The measure introduces several methodological refinements which have not been applied concurrently in previous efforts: a wide coverage of the different dimensions of the urban form, together with the use of a distance-based decay function and modelling-based weighing of the variables.


Tidal Variability Related To Sea Level Variability In The Pacific Ocean, Adam Thomas Devlin, David A. Jay, Edward Zaron, Stefan A. Talke, Jiayi Pan, Hui Lin Nov 2017

Tidal Variability Related To Sea Level Variability In The Pacific Ocean, Adam Thomas Devlin, David A. Jay, Edward Zaron, Stefan A. Talke, Jiayi Pan, Hui Lin

Civil and Environmental Engineering Faculty Publications and Presentations

Ocean tides are changing worldwide for reasons unrelated to astronomical forcing. Changes in tidal properties coupled with altered mean sea level (MSL) may yield higher peak water levels and increased occurrence of short-term exceedance events, such as storm surge and nuisance flooding. Here we investigate the hypothesis that changes in relative sea level are correlated with alterations in tidal amplitudes. Our approach focuses on the correlation between short-term (monthly to interannual) fluctuations in sea level with changes in tidal properties of major ocean tides (M2, and K1; S2 and O1) at 152 gauges. …


Evaluation Of Roadway Reallocation Projects: Analysis Of Before-And-After Travel Speeds And Congestion Utilizing High-Resolution Bus Transit Data, Miguel A. Figliozzi, Travis B. Glick Nov 2017

Evaluation Of Roadway Reallocation Projects: Analysis Of Before-And-After Travel Speeds And Congestion Utilizing High-Resolution Bus Transit Data, Miguel A. Figliozzi, Travis B. Glick

TREC Final Reports

The traditional process of identifying corridors for road diet improvements involves selecting potential corridors (mostly based on identifying fourlane roads) and conducting a traffic impact analysis of proposed changes on a selected roadway before implementing changes. The evaluation of roadway reallocation projects should include the analysis of traffic volumes, level of service, speeds, queue lengths and bus operations. There are tools and equipment to evaluate effectively traffic volumes and level of service changes in before-and-after studies. However, the detailed evaluation of speed and queue length distributions along a segment are significantly more cumbersome. In addition, the exhaustive evaluation of bus …


Evaluation Of Roadway Reallocation Projects, Miguel Figliozzi Nov 2017

Evaluation Of Roadway Reallocation Projects, Miguel Figliozzi

TREC Project Briefs

This NITC study offers a new methodology for evaluating the before-and-after effects of roadway space reallocation projects.


An Analysis Of The Optimal Mix Of Global Energy Resources And The Potential Need For Geoengineering Using The Ceagom Model, John George Anasis, M. A. K. Khalil, George G. Lendaris, Christopher L. Butenhoff, Randall Bluffstone Oct 2017

An Analysis Of The Optimal Mix Of Global Energy Resources And The Potential Need For Geoengineering Using The Ceagom Model, John George Anasis, M. A. K. Khalil, George G. Lendaris, Christopher L. Butenhoff, Randall Bluffstone

Systems Science Faculty Publications and Presentations

Humanity faces tremendous challenges as a result of anthropogenic climate change caused by greenhouse gas emissions. The mix of resources deployed in order to meet the energy needs of a growing global population is key to addressing the climate change issue. The goal of this research is to examine the optimal mix of energy resources that should be deployed to meet a forecast global energy demand while still meeting desired climate targets. The research includes the unique feature of examining the role that geoengineering can play in this optimization. The results show that some form of geoengineering is likely to …


Eulerian-Based Virtual Visual Sensors To Measure Dynamic Displacements Of Structures, Ali Shariati, Thomas Schumacher Oct 2017

Eulerian-Based Virtual Visual Sensors To Measure Dynamic Displacements Of Structures, Ali Shariati, Thomas Schumacher

Civil and Environmental Engineering Faculty Publications and Presentations

Vibration measurements provide useful information about a structural system's dynamic characteristics and are used in many fields of science and engineering. Here, we present an alternative noncontact approach to measure dynamic displacements of structural systems using digital videos. The concept is that intensity measured at a pixel with a fixed (or Eulerian) coordinate in a digital video can be regarded as a virtual visual sensor. The pixels in the vicinity of the boundary of a vibrating structural element contain useful frequency information, which we have been able to demonstrate in earlier studies. Our ultimate goal, however, is to be able …


Drones For Commercial Last-Mile Deliveries: A Discussion Of Logistical, Environmental, And Economic Trade-Offs, Miguel Figliozzi Sep 2017

Drones For Commercial Last-Mile Deliveries: A Discussion Of Logistical, Environmental, And Economic Trade-Offs, Miguel Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

There are no studies that model the potential effectiveness of Unmanned Aerial Vehicles (UAVs) or drones to reduce CO2e lifecycle (including both utilization and vehicle phase) emissions when compared to conventional diesel vans, electric trucks, electric vans, and tricycles. This study presents a novel analysis of lifecycle UAV and ground commercial vehicles CO2e emissions.


Lifetime Reliability-Based Optimization Of Post-Tensioned Box-Girder Bridges, Tatiana García-Segura, Victor Yepes, Dan M. Frangopol, David Y. Yang Aug 2017

Lifetime Reliability-Based Optimization Of Post-Tensioned Box-Girder Bridges, Tatiana García-Segura, Victor Yepes, Dan M. Frangopol, David Y. Yang

Civil and Environmental Engineering Faculty Publications and Presentations

This paper presents a lifetime reliability-based approach for the optimization of post-tensioned concrete box-girder bridges under corrosion attack. The proposed approach is illustrated by determining the optimal life-cycle cost and CO2 emissions of several initial designs of post-tensioned box-girder bridges with different objectives, i.e. the lowest initial costs, the longest corrosion initiation time, or the maximum safety. The study was conducted in two steps. Firstly, the Pareto set presents initial designs considering the cross-section geometry, the concrete strength, the reinforcing steel and the prestressing steel. Secondly, the maintenance optimization was conducted with the proposed method, aimed at minimizing the economic, …


Archival Water-Level Measurements: Recovering Historical Data To Help Design For The Future, Stefan A. Talke, David A. Jay Aug 2017

Archival Water-Level Measurements: Recovering Historical Data To Help Design For The Future, Stefan A. Talke, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

Improving methods of assessing risk and designing structures to withstand extreme events and changing sea levels is a vital component of strategies for reducing risk to coastal resources and assets. An obvious approach to improving the statistical robustness of risk assessments is to increase the number, time span, and quality of available water-level data sets, and to assess trends and non-stationarity. In this report we discuss efforts to recover, digitize, and analyze hundreds of station-years of lost-and-forgotten tide data and other water-level measurements that extend back to the early 19th century. To date, more than 6,500 station-years of previously lost …


Building Intelligence In The Automated Traffic Signal Performance Measures With Advanced Data Analytics, Tingting Huang, Subhadipto Poddar, Chris Aguilar, Anuj Sharma, Edward J. Smaglik, Sirisha Kothuri, Peter Koonce Aug 2017

Building Intelligence In The Automated Traffic Signal Performance Measures With Advanced Data Analytics, Tingting Huang, Subhadipto Poddar, Chris Aguilar, Anuj Sharma, Edward J. Smaglik, Sirisha Kothuri, Peter Koonce

Civil and Environmental Engineering Faculty Publications and Presentations

Automated traffic signal performance measures (ATSPMs) are an effort to equip traffic signal controllers with high-resolution data-logging capabilities and utilize this data to generate performance measures. These measures allow practitioners to improve operations as well as to maintain and operate their systems in a safe and efficient manner. Although these measures have changed the way that operators manage their systems, several shortcomings of the tool, identified by talking with signal operators, are a lack of data quality control and the extent of resources required to properly use the tool for system-wide management. To address these shortcomings, intelligent traffic signal performance …


A Simulator-Based Analysis Of Engineering Treatments For Right-Hook Bicycle Crashes At Signalized Intersections, Jennifer Warner, David S. Hurwitz, Christopher M. Monsere, Kayla Fleskes Jul 2017

A Simulator-Based Analysis Of Engineering Treatments For Right-Hook Bicycle Crashes At Signalized Intersections, Jennifer Warner, David S. Hurwitz, Christopher M. Monsere, Kayla Fleskes

Civil and Environmental Engineering Faculty Publications and Presentations

A right-hook crash is a crash between a right-turning motor vehicle and an adjacent through-moving bicycle. At signalized intersections, these crashes can occur during any portion of the green interval when conflicting bicycles and vehicles are moving concurrently. The objective of this research was to evaluate the effectiveness of four types of engineering countermeasures – regulatory signage, intersection pavement marking, smaller curb radius, and protected intersection design – at modifying driver behaviors that are known contributing factors in these crashes. This research focused on right-hook crashes that occur during the latter stage of the circular green indication at signalized intersections …


Time Varying Parameter Models For Catchments With Land Use Change: The Importance Of Model Structure, Sahani Pathiraja, Daniela Anghileri, Paolo Burlando, Ashish Sharma, Lucy Marshall, Hamid Moradkhani Jul 2017

Time Varying Parameter Models For Catchments With Land Use Change: The Importance Of Model Structure, Sahani Pathiraja, Daniela Anghileri, Paolo Burlando, Ashish Sharma, Lucy Marshall, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

Rapid population and economic growth in South-East-Asia has been accompanied by extensive land use change with consequent impacts on catchment hydrology. Modelling methodologies capable of handling changing land use conditions are therefore becoming ever more important, and are receiving increasing attention from hydrologists. A recently developed Data Assimilation based framework that allows model parameters to vary through time in response to signals of change in observations is considered for a medium sized catchment (2880 km²) in Northern Vietnam experiencing substantial but gradual land cover change. We investigate the efficacy of the method as well as the importance of the chosen …


Considering Health In Us Metropolitan Long-Range Transportation Plans: A Review Of Guidance Statements And Performance Measures, Patrick A. Singleton, Kelly J. Clifton Jul 2017

Considering Health In Us Metropolitan Long-Range Transportation Plans: A Review Of Guidance Statements And Performance Measures, Patrick A. Singleton, Kelly J. Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

Transportation influences health primarily and most directly through traffic safety, air quality, physical activity, and accessibility. Despite the importance of all four components, only safety and air quality are typically considered during institutionalized transportation planning processes. This paper assesses how health impacts are considered in transportation planning by focusing on the long-range transportation plans that US metropolitan planning organizations develop. We analyzed the content of current plans from 25 large regions, reviewing how policy guidance statements and supporting performance measures addressed health. Goals and objectives exhibited an incomplete perspective of transportation's effects on health, focusing on safety, accessibility, and air …


Land Use And Active Travel: A Complex Relationship, Steven R. Gehrke Jun 2017

Land Use And Active Travel: A Complex Relationship, Steven R. Gehrke

TREC Project Briefs

While it’s accepted that mixed-use development promotes active travel, researchers don’t have a consensus on exactly how land use determines people’s travel patterns.


Focusing On Equity In Regional Plans, Kristine M. Williams Jun 2017

Focusing On Equity In Regional Plans, Kristine M. Williams

TREC Project Briefs

Metropolitan planning organizations (MPOs) have long been required to consider the equity implications of their regional transportation plans and processes.


Peer-To-Peer Carsharing: Short-Term Effects On Travel Behavior In Portland, Or, Jennifer Dill, Nathan Mcneil, Steven Howland May 2017

Peer-To-Peer Carsharing: Short-Term Effects On Travel Behavior In Portland, Or, Jennifer Dill, Nathan Mcneil, Steven Howland

TREC Final Reports

Peer-to-peer (P2P) carsharing is a relatively new concept in the U.S. Enabled by recent internet and mobile technology development, P2P carsharing generally involves a facilitating company connecting private vehicle owners to people who are interested in renting a vehicle. P2P carsharing has many things in common with business-to-consumer (B2C) carsharing services. Consumers join the service to rent vehicles on a short-term basis from locations dispersed throughout a certain area. Both services may allow households to reduce their private car ownership. However, P2P carsharing differs substantially from other models in that there are two distinct sets of consumers: those who rent …


Evaluating The Distributional Effects Of Regional Transportation Plans And Projects, Kristine Williams, Aaron Golub May 2017

Evaluating The Distributional Effects Of Regional Transportation Plans And Projects, Kristine Williams, Aaron Golub

TREC Final Reports

Metropolitan planning organizations (MPOs) have long been required to consider the equity implications of their regional transportation plans and processes. Funded by the National Institute for Transportation and Communities, this research aims to provide additional guidance to MPOs on how to evaluate distributional equity in regional plans and projects. The report begins with an overview of federal requirements related to equity in transportation planning. We then synthesize contemporary methods for measuring transportation equity and the distributional effects of plans and projects from a review of the literature and MPO plans and studies. The report concludes with exploratory case studies of …


Using An Altimeter-Derived Internal Tide Model To Remove Tides From In Situ Data, Edward D. Zaron, Richard D. Ray May 2017

Using An Altimeter-Derived Internal Tide Model To Remove Tides From In Situ Data, Edward D. Zaron, Richard D. Ray

Civil and Environmental Engineering Faculty Publications and Presentations

Internal waves at tidal frequencies, i.e., the internal tides, are a prominent source of variability in the ocean associated with significant vertical isopycnal displacements and currents. Because the isopycnal displacements are caused by ageostrophic dynamics, they contribute uncertainty to geostrophic transport inferred from vertical profiles in the ocean. Here it is demonstrated that a newly developed model of the main semidiurnal (M2) internal tide derived from satellite altimetry may be used to partially remove the tide from vertical profile data, as measured by the reduction of steric height variance inferred from the profiles. It is further demonstrated that the internal …


Narratives Of Marginalized Cyclists: Understanding Obstacles To Utilitarian Cycling Among Women And Minorities In Portland, Or, Amy Lubitow May 2017

Narratives Of Marginalized Cyclists: Understanding Obstacles To Utilitarian Cycling Among Women And Minorities In Portland, Or, Amy Lubitow

TREC Final Reports

Research has demonstrated that everyday or utilitarian forms of cycling are most likely to generate positive population-level health impacts (Garrard et al., 2012), yet significant deterrents to routine cycling remain, particularly for women and minorities. The primary aim of this project was to conduct a qualitative interview study that generated rich, narrative data regarding obstacles to routine or utilitarian cycling for women and minorities who already see biking as a viable form of transit, but who make relatively few bike trips. A secondary aim of the project was to develop a set of specific interventions that have the potential to …


Dynamic Evaluation Of Transportation Structures With Ipod-Based Data Acquisition, Charles Riley Apr 2017

Dynamic Evaluation Of Transportation Structures With Ipod-Based Data Acquisition, Charles Riley

TREC Final Reports

This grant supported coursework and laboratory development and expanded research capacity, promoting (a) innovative learning activities that expose students to cutting-edge methods of bridge structural health and behavior monitoring and (b) research by our growing group of graduate students using developing technologies (specifically, shake tables and iPods with on-board accelerometers). As transportation infrastructure reaches and exceeds its design life, engineering efforts are turning to evaluation, rehabilitation and repair. Accurately assessing structures to determine their future performance and remaining life is becoming a primary job function for many civil engineers.

As part of this project, graduate students worked with the PI …


Design For An Aging Population, Trygve Faste, Kiersten Muenchinger Apr 2017

Design For An Aging Population, Trygve Faste, Kiersten Muenchinger

TREC Final Reports

Older Americans are increasing in numbers and addressing their needs through better public transportation design will improve their quality of life. This study sought to increase understanding of the obstacles faced by people with impairments in vision, hearing and/or mobility, which are common issues for older people, and generate physical product solutions. The research was conducted to conceptualize products, structures and services to reduce or eliminate these obstacles.

With a focus on the Eugene, OR, public bus system, elderly riders were surveyed and interviewed. Designers rode on buses noting what worked well and where problems arose. Five ride-along observations of …


Remote Measurements Of Tides And River Slope Using An Airborne Lidar Instrument, Austin S. Hudson, Stefan A. Talke, Ruth Branch, Chris Chickadel, Gordon Farquharson, Andrew Jessup Apr 2017

Remote Measurements Of Tides And River Slope Using An Airborne Lidar Instrument, Austin S. Hudson, Stefan A. Talke, Ruth Branch, Chris Chickadel, Gordon Farquharson, Andrew Jessup

Civil and Environmental Engineering Faculty Publications and Presentations

Tides and river slope are fundamental characteristics of estuaries, but they are usually undersampled due to deficiencies in the spatial coverage of water level measurements. This study aims to address this issue by investigating the use of airborne lidar measurements to study tidal statistics and river slope in the Columbia River estuary. Eight plane transects over a 12-h period yield at least eight independent measurements of water level at 2.5-km increments over a 65-km stretch of the estuary. These data are fit to a sinusoidal curve and the results are compared to seven in situ gauges. In situ– and lidar-based …


Using Satellite Observations To Characterize The Response Of Estuarine Turbidity Maxima To External Forcing, Austin S. Hudson, Stefan A. Talke, David A. Jay Mar 2017

Using Satellite Observations To Characterize The Response Of Estuarine Turbidity Maxima To External Forcing, Austin S. Hudson, Stefan A. Talke, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

This study explores the spatial and temporal character of turbidity maxima in the Columbia River Estuary (CRE) using satellite observations. Surface reflectance data measured by the Moderate Imaging Spectroradiometer (MODIS) were calibrated against in situ measurements of surface turbidity (R2 = 0.85 for 205 measurements). More than 1500 satellite images from 2000 to 2015 were then conditionally sampled to explore the physical processes that drive the spatial distribution of the turbidity field. We find satellite measurements are able to describe seasonal, spring–neap, and spatial features of the estuarine turbidity maxima (ETM) that are not easily observable by other means. System-wide …


Benzene Formation In Electronic Cigarettes, James F. Pankow, Kilsun Kim, Kevin J. Mcwhirter, Wentai Luo, Jorge O. Escobedo, Robert M. Strongin, Anna K. Duell, David H. Peyton Mar 2017

Benzene Formation In Electronic Cigarettes, James F. Pankow, Kilsun Kim, Kevin J. Mcwhirter, Wentai Luo, Jorge O. Escobedo, Robert M. Strongin, Anna K. Duell, David H. Peyton

Chemistry Faculty Publications and Presentations

The heating of the fluids used in electronic cigarettes (“e-cigarettes”) used to create “vaping” aerosols is capable of causing a wide range of degradation reaction products. We investigated formation of benzene (an important human carcinogen) from e-cigarette fluids containing propylene glycol (PG), glycerol (GL), benzoic acid, the flavor chemical benzaldehyde, and nicotine.


Mass Exchange Dynamics Of Surface And Subsurface Oil In Shallow-Water Transport, Saeed Moghimi, Jorge Ramirez, Juan M. Restrepo, Shankar Venkataramani Mar 2017

Mass Exchange Dynamics Of Surface And Subsurface Oil In Shallow-Water Transport, Saeed Moghimi, Jorge Ramirez, Juan M. Restrepo, Shankar Venkataramani

Civil and Environmental Engineering Faculty Publications and Presentations

We formulate a model for the mass exchange between oil at and below the sea surface. This is a particularly important aspect of modeling oil spills. Surface and subsurface oil have different chemical and transport characteristics and lumping them together would compromise the accuracy of the resulting model. Without observational or computational constraints, it is thus not possible to quantitatively predict oil spills based upon partial field observations of surface and/or sub-surface oil. The primary challenge in capturing the mass exchange is that the principal mechanisms are on the microscale. This is a serious barrier to developing practical models for …


Improving Walkability Through Control Strategies At Signalized Intersections, Sirisha Murthy Kothuri, Andrew Kading, Edward J. Smaglik, Christopher Sobie Jan 2017

Improving Walkability Through Control Strategies At Signalized Intersections, Sirisha Murthy Kothuri, Andrew Kading, Edward J. Smaglik, Christopher Sobie

TREC Final Reports

As cities and communities nationwide seek to develop Complete Streets that foster livability and accommodate all modes, signal timing control strategies that include pedestrians in the operational decision process are gaining importance. This research tested several efficiency-focused pedestrian treatments – coordination, actuated-coordination, free operation, short cycle lengths – and safety-focused treatment including leading pedestrian intervals and Barnes Dance. Using a software-in-the-loop simulation, the operational impacts of these treatments on all users (vehicles, heavy vehicles, bicyclists and pedestrians) at an intersection were evaluated. Results showed that among the efficiency-based treatments, free operation was most beneficial for reducing minor-street pedestrian delays. Both …


A Practitioner's Guide To Urban Trip Generation, Kristina Marie Currans Jan 2017

A Practitioner's Guide To Urban Trip Generation, Kristina Marie Currans

TREC Project Briefs

In 1976, the Institute of Transportation Engineers (ITE) compiled their first Handbook of guidelines for evaluating development-level transportation impacts. Decades later, these methods are still ubiquitously used across the US and Canada. Only recently, with the third edition of the ITE Trip Generation Handbook, have new data and approaches been adopted. In this study NITC researcher Kristina Currans takes aim at understanding issues inherent in the collection and application of ITE’s data and methods in various urban contexts. This technology transfer guide touches on the main findings from this work.


Issues In Trip Generation Methods For Transportation Impact Estimation Of Land Use Development: A Review And Discussion Of The State-Of-The-Art Approaches, Kristina Marie Currans Jan 2017

Issues In Trip Generation Methods For Transportation Impact Estimation Of Land Use Development: A Review And Discussion Of The State-Of-The-Art Approaches, Kristina Marie Currans

Civil and Environmental Engineering Faculty Publications and Presentations

As agencies develop more robust planning objectives for creating sustainable and livable communities, the research community has continued developing supportive tools and methods to provide more accurate and robust means for estimating transportation impacts for site-level development review. This paper is a review of the state-of-the-art trip generation methods for land use transportation impact estimation. First, it provides an overview of the more recent available and peer-reviewed estimation methods. Second, the authors offer a discussion of the successes of state-of-the-art approaches using common themes of research to identify corresponding consistency with theories of travel behavior and urban economics. These themes …


Accessibility, Income, And Person Trip Generation: Multilevel Model Of Activity At Food Retail Establishments In Portland, Oregon, Kristina Marie Currans, Kelly Clifton Jan 2017

Accessibility, Income, And Person Trip Generation: Multilevel Model Of Activity At Food Retail Establishments In Portland, Oregon, Kristina Marie Currans, Kelly Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

In the past decade, the methods for estimating multimodal transportation impacts of urban land use development have improved substantially. One assumption commonly made in these new methods is that overall person-trip rates at similarly-sized establishments of the same land use do not vary across a region. This is an assumption of convenience to permit the adjustment of ITE Trip Generation vehicle trip rates for use in different urban environments. However, this assumption is inconsistent with theories of urban economics, which recognize that businesses pay a premium to locate in areas with high levels of accessibility to attract more customers. In …


Relative Sea-Level Trends In New York City During The Past 1500 Years, Andrew C. Kemp, Troy D. Hill, Christopher H. Vane, Niamh Cahill, Philip M. Orton, Stefan A. Talke, Andrew C. Parnell, Kelsey Sanborn, Ellen K. Hartig Jan 2017

Relative Sea-Level Trends In New York City During The Past 1500 Years, Andrew C. Kemp, Troy D. Hill, Christopher H. Vane, Niamh Cahill, Philip M. Orton, Stefan A. Talke, Andrew C. Parnell, Kelsey Sanborn, Ellen K. Hartig

Civil and Environmental Engineering Faculty Publications and Presentations

New York City (NYC) is threatened by 21st-century relative sea-level (RSL) rise because it will experience a trend that exceeds the global mean and has high concentrations of low-lying infrastructure and socioeconomic activity. To provide a long-term context for anticipated trends, we reconstructed RSL change during the past ~1500 years using a core of salt-marsh sediment from Pelham Bay in The Bronx. Foraminifera and bulk-sediment δ13C values were used as sea-level indicators. The history of sediment accumulation was established by radiocarbon dating and recognition of pollution and land-use trends of known age in down-core elemental, isotopic, and pollen …