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Terrestrial Carbon Stocks across a Gradient of Urbanization: A Study of the Seattle, WA Region

Hutyra, Lucy R.; Yoon, Byungman; Alberti, Marina. (2011). Terrestrial Carbon Stocks across a Gradient of Urbanization: A Study of the Seattle, WA Region. Global Change Biology, 17(2), 783 – 797.

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Abstract

Most of our global population and its CO2 emissions can be attributed to urban areas. The process of urbanization changes terrestrial carbon stocks and fluxes, which, in turn, impact ecosystem functions and atmospheric CO2 concentrations. Using the Seattle, WA, region as a case study, this paper explores the relationships between aboveground carbon stocks and land cover within an urbanizing area. The major objectives were to estimate aboveground live and dead terrestrial carbon stocks across multiple land cover classes and quantify the relationships between urban cover and vegetation across a gradient of urbanization. We established 154 sample plots in the Seattle region to assess carbon stocks as a function of distance from the urban core and land cover [urban (heavy, medium, and low), mixed forest, and conifer forest land covers]. The mean (and 95% CI) aboveground live biomass for the region was 89 +/- 22 Mg C ha-1 with an additional 11.8 +/- 4 Mg C ha-1 of coarse woody debris biomass. The average live biomass stored within forested and urban land covers was 140 +/- 40 and 18 +/- 14 Mg C ha-1, respectively, with a 57% mean vegetated canopy cover regionally. Both the total carbon stocks and mean vegetated canopy cover were surprisingly high, even within the heavily urbanized areas, well exceeding observations within other urbanizing areas and the average US forested carbon stocks. As urban land covers and populations continue to rapidly increase across the globe, these results highlight the importance of considering vegetation in urbanizing areas within the terrestrial carbon cycle.

Keywords

Urbanization & The Environment; Carbon Cycle; Carbon In Soils; Climate Change Prevention; Population & The Environment; Land Cover; Cities & Towns -- Environmental Conditions; Seattle (wash.); Washington (state); Climate Change; Development; Mitigation; Pacific Northwest; Urban; United-states; Woody Debris; Storage; Growth; Responses; Fluxes; Co2; Sequestration; Landscape; Forests

Occupant Perceptions of an Indoor Thermal Environment in a Naturally Ventilated Building

Ilyas, Salman; Emery, Ashley; Heerwagen, Judith; Heerwagen, Dean. (2012). Occupant Perceptions of an Indoor Thermal Environment in a Naturally Ventilated Building. Ashrae Transactions, 118(2), 114 – 121.

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Abstract

A strong emphasis is currently being placed on the use of natural ventilation as a means for providing a safe and healthful indoor environment as part of green building programs. There has been an increasing interest in developing natural ventilation design strategies that can furnish adequate fresh air to the building interior and simultaneously control the indoor air quality effectively, while providing significant energy savings. In naturally ventilated spaces, furnishing a suitable air exchange rate between the building exterior and interior can create a thermally comfortable and healthy indoor environment. However, the air exchange must occur such that the indoor air quality of the building is not compromised and thermally comfortable conditions for the occupants can be maintained. Architecture Hall is a recently renovated, naturally ventilated building located on the University of Washington campus in Seattle. The natural ventilation in this building was evaluated using a variety of experimental techniques, which included measurement of carbon dioxide (CO2) levels, air exchange rates and air velocities. High CO2 concentrations are a good indicator of inadequate ventilation rates and poor air movement in a space. Hence, a number of standards and certification programs specify the use of outdoor air monitoring based on CO2 concentrations in an occupied space. Occupant surveys, based on a U.S. EPA study, were also administered to understand and analyse occupant perceptions about the indoor thermal environment and to identify the prevalence of any building related illness symptoms. The discussion in this paper will focus on the findings of the occupant surveys and how they relate to the measured CO2 levels, air exchange rates and air velocities in the naturally ventilated spaces. The natural ventilation function in Architecture Hall is largely climate driven. For the period of November through March particularly, outside temperatures are quite low and windows are seldom opened by the occupants, in spite of a large number of occupants being dissatisfied with the indoor environmental quality. Consequently, CO2 concentrations consistently exceed acceptable levels and very little air movement is recorded. [ABSTRACT FROM AUTHOR]; Copyright of ASHRAE Transactions is the property of ASHRAE and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Keywords

Thermal Comfort; Natural Ventilation; Energy Consumption Of Buildings; Indoor Air Quality; Heat Exchangers; Carbon Dioxide

Study of the Relationship between Procurement Duration and Project Performance in Design-Build Projects: Comparison between Water/Wastewater and Transportation Sectors

Bogus, Susan M.; Migliaccio, Giovanni C.; Jin, Ruoyu. (2013). Study of the Relationship between Procurement Duration and Project Performance in Design-Build Projects: Comparison between Water/Wastewater and Transportation Sectors. Journal Of Management In Engineering, 29(4), 382 – 391.

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Abstract

Previous studies on building, industrial, and transportation projects found that projects delivered using design-build tend to perform better than projects delivered with the traditional design-bid-build method. However, performance of design-build projects is affected by various factors, with procurement-related factors being among the most influential. Whereas other aspects of procurement have been largely investigated, the effect of procurement duration on project performance has been studied only for design-build transportation projects. In addition, few studies have focused specifically on the delivery of water/wastewater projects. This paper includes the results of a study on the relationship between procurement duration and performance of water/wastewater design-build projects. The study methodology was based on regression analysis of data from a sample of water/wastewater design-build projects. The results show that unlike the transportation sector, procurement duration has little effect on either schedule or cost performance in the water/wastewater sector. Likely reasons for this difference were then explored through a content analysis of procurement documents. (C) 2013 American Society of Civil Engineers.

Keywords

Design Engineering; Procurement; Project Management; Regression Analysis; Transportation; Waste Management; Procurement Documents; Schedule Performance; Cost Performance; Design-build Transportation Projects; Procurement-related Factors; Design-bid-build Method; Water-wastewater Sectors; Transportation Sectors; Project Performance; Procurement Duration; Design/build; Project Delivery; Water; Wastewater

Does Neighborhood Walkability Moderate the Effects of Intrapersonal Characteristics on Amount of Walking in Post-Menopausal Women?

Perry, Cynthia K.; Herting, Jerald R.; Berke, Ethan M.; Nguyen, Huong Q.; Moudon, Anne Vernez; Beresford, Shirley A. A.; Ockene, Judith K.; Manson, Joann E.; Lacroix, Andrea Z. (2013). Does Neighborhood Walkability Moderate the Effects of Intrapersonal Characteristics on Amount of Walking in Post-Menopausal Women? Health & Place, 21, 39 – 45.

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Abstract

This study identifies factors associated with walking among postmenopausal women and tests whether neighborhood walkability moderates the influence of intrapersonal factors on walking. We used data from the Women's Health Initiative Seattle Center and linear regression models to estimate associations and interactions. Being white and healthy, having a high school education or beyond and greater non-walking exercise were significantly associated with more walking. Neighborhood walkability was not independently associated with greater walking, nor did it moderate influence of intrapersonal factors on walking. Specifying types of walking (e.g., for transportation) can elucidate the relationships among intrapersonal factors, the built environment, and walking. (C) 2013 Elsevier Ltd. All rights reserved.

Keywords

Self-talk; Postmenopause; Walking; Women's Health; Built Environment; Social Interaction; Regression Analysis; Postmenopausal Women; Walkability; Physical-activity; Older-adults; United-states; Us Adults; Exercise; Obesity; Transportation; Association; Attributes

Environments Perceived as Obesogenic Have Lower Residential Property Values

Drewnowski, Adam; Aggarwal, Anju; Rehm, Colin D.; Cohen-Cline, Hannah; Hurvitz, Philip M.; Moudon, Anne V. (2014). Environments Perceived as Obesogenic Have Lower Residential Property Values. American Journal Of Preventive Medicine, 47(3), 260 – 274.

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Abstract

Background: Studies have tried to link obesity rates and physical activity with multiple aspects of the built environment. Purpose: To determine the relation between residential property values and multiple perceived (self-reported) measures of the obesogenic environment. Methods: The Seattle Obesity Study (SOS) used a telephone survey of a representative, geographically distributed sample Of 2,001 King County adults, collected in 2008-2009 and analyzed in 2012-2013. Home addresses were geocoded. Residential property values at the tax parcel level were obtained from the King County tax assessor. Mean residential property values within a 10-minute walk (833-m buffer) were calculated for each respondent. Data on multiple perceived measures of the obesogenic environment were collected by self-report. Correlations and multi-variable linear regression analyses, stratified by residential density, were used to examine the associations among perceived environmental measures, property values, and BMI. Results: Perceived measures of the environment such as crime, heavy traffic, and proximity to bars, liquor stores, and fast food were all associated with lower property values. By contrast, living in neighborhoods that were perceived as safe, quiet, clean, and attractive was associated with higher property values. Higher property values were associated, in turn, with lower BMIs among women. The observed associations between perceived environment measures and BMI were largely attenuated after accounting for residential property values. Conclusions: Environments perceived as obesogenic are associated with lower property values. Studies in additional locations need to explore to what extent other perceived environment measures can be reflected in residential property values. (C) 2014 American Journal of Preventive Medicine

Keywords

Body-mass Index; Physical-activity; Objective Measures; Childhood Obesity; Food Stores; Neighborhood Disorder; Atherosclerosis Risk; Collective Efficacy; Racial Composition; Built Environment

A User-centered Information And Communication Technology (ict) Tool To Improve Safety Inspections.

Lin, Ken-yu; Tsai, Meng-han; Gatti, Umberto C.; Lin, Jacob Je-chian; Lee, Cheng-hao; Kang, Shih-chung. (2014). A User-centered Information And Communication Technology (ict) Tool To Improve Safety Inspections. Automation In Construction, 48, 53 – 63.

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Abstract

Occupational safety is imperative in construction, and safety inspection is among the most common practices that help enforce job safety on site. The safety inspection process, however, suffers from several drawbacks that hinder the efficiency, effectiveness, and analytical learning capacity of the process. Dedicated tools for user-centered information and communications technology could significantly reduce such drawbacks. This paper discusses the use of an original two-step user-centered design approach to develop and evaluate an iPad application that aims to address such drawbacks and improve the day-to-day practices and management of safety inspections. Evaluation results indicate the usefulness and practicality of the application and identify innovative uses not previously envisioned. Furthermore, the developed tool allows consistent data collection that can eventually be used to aid the development of advanced safety and health data analysis techniques. (C) 2014 Elsevier B.V. All rights reserved.

Keywords

Information & Communication Technologies; Industrial Safety; Data Analysis; Technological Innovations; Ipads; Construction Safety; Field Data Collection; Field Inspection; Information And Communication Technology; Research To Practice; Safety Audit; Safety Inspection; Safety Technology; Site Inspection; User-centered Design; User-centered Information And Communication Technology Tool; Safety Inspection Process; Occupational Safety; Job Safety; Analytical Learning Capacity; Communications Technology; Two-step User-centered Design Approach; Ipad Application; Innovative Uses; Consistent Data Collection; Construction; Advanced Safety-health Data Analysis Techniques; Construction Industry; Information Technology; Inspection; Occupational Health; User Centred Design; Construction Site Safety; Management-system; Design; Productivity

Worksite Neighborhood and Obesogenic Behaviors: Findings among Employees in the Promoting Activity and Changes in Eating (PACE) Trial

Barrington, Wendy E.; Beresford, Shirley A. A.; Koepsell, Thomas D.; Duncan, Glen E.; Moudon, Anne Vernez. (2015). Worksite Neighborhood and Obesogenic Behaviors: Findings among Employees in the Promoting Activity and Changes in Eating (PACE) Trial. American Journal Of Preventive Medicine, 48(1), 31 – 41.

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Abstract

Background: Understanding mechanisms linking neighborhood context to health behaviors may provide targets for increasing lifestyle intervention effectiveness. Although associations between home neighborhood and obesogenic behaviors have been studied, less is known about the role of worksite neighborhood. Purpose: To evaluate associations between worksite neighborhood context at baseline (2006) and change in obesogenic behaviors of adult employees at follow-up (2007-2009) in a worksite randomized trial to prevent weight gain. Methods: Worksite property values were used as an indicator of worksite neighborhood SES (NSES). Worksite neighborhood built environment attributes associated with walkability were evaluated as explanatory factors in relationships among worksite NSES, diet, and physical activity behaviors of employees. Behavioral data were collected at baseline (2005-2007) and follow-up (2007-2009). Multilevel linear and logistic models were constructed adjusting for covariates and accounting for clustering within worksites. Product-of-coefficients methods were used to assess mediation. Analyses were performed after study completion (2011-2012). Results: Higher worksite NSES was associated with more walking (OR = 1.16, 95% CI = 1.03, 1.30, p = 0.01). Higher density of residential units surrounding worksites was associated with more walking and eating five or more daily servings of fruits and vegetables, independent of worksite NSES. Residential density partially explained relationships among worksite NSES, fruit and vegetable consumption, and walking. Conclusions: Worksite neighborhood context may influence employees' obesogenic behaviors. Furthermore, residential density around worksites could be an indicator of access to dietary and physical activity-related infrastructure in urban areas. This may be important given the popularity of worksites as venues for obesity prevention efforts. Published by Elsevier Inc. on behalf of American Journal of Preventive Medicine.

Keywords

Health Behavior; Food Habits; Lifestyles & Health; Prevention Of Obesity; Employee Health Promotion; Follow-up Studies (medicine); Local Food Environment; Dietary Energy Density; Body-mass Index; Socioeconomic-status; Physical-activity; Built Environment; Longitudinal-associations; Walking Behavior; Restaurant Use; Weight-gain

Empirical Comparison of Methods for Estimating Location Cost Adjustments Factors

Migliaccio, G. C.; Zandbergen, Paul; Martinez, A. A. (2015). Empirical Comparison of Methods for Estimating Location Cost Adjustments Factors. Journal Of Management In Engineering, 31(2).

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Abstract

Location factors are used to adjust conceptual cost estimates by project location. Presently, the construction industry has adopted a simple, proximity-based interpolation method to estimate location factors for missing locations. Although this approach is widely accepted, its validity has not been statistically substantiated. This study assessed the current method of adjusting conceptual cost estimates by project location and compared its performance against two alternative spatial interpolation methods. A Moran's I test was used to confirm the presence of strong spatial autocorrelation, which supports the use of proximity-based methods. Additional statistical evaluations of current and alternative methods were also conducted. Results provided statistical justification for the current method. However, an alternative method was proven to outperform the current method. Moreover, several opportunities for future research were identified as a result of this exploratory study. (C) 2014 American Society of Civil Engineers.

Keywords

Construction Industry; Interpolation; Statistical Analysis; Location Cost Adjustment Factor; Proximity-based Interpolation Method; Project Location; Spatial Interpolation Method; Moran I Test; Spatial Autocorrelation; Statistical Evaluation; Geographical Information-systems; Construction; Layout; Gis; Conceptual Estimating; Geographic Information Systems; Construction Costs; Planning; Location Adjustments

Evaluating the Strength of Text Classification Categories for Supporting Construction Field Inspection

Chi, Nai-wen; Lin, Ken-yu; El-Gohary, Nora; Hsieh, Shang-hsien. (2016). Evaluating the Strength of Text Classification Categories for Supporting Construction Field Inspection. Automation In Construction, 64, 78 – 88.

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Abstract

Field inspection is a common approach to the prevention of on-site accidents in the construction industry, which aims to identify and correct violations before they result in accidents. While conducting a field inspection, quite often safety professionals need to consult applicable construction safety standards. By doing so, they can make informed judgments on the violations and reference applicable standards. Text classification (TC) can be used to classify safety standards based on the types and causes of violations. Safety professionals can therefore use violation types and causes as indices to quickly locate applicable standards. Defining TC categories (or labels) is the first important step in performing TC, because satisfactory results cannot be achieved without appropriate TC categories. Researchers often determine applicable TC categories based on the important topics within a knowledge domain. However, not all TC categories can yield satisfactory TC results because some of them are not associated with strong and specific keywords that can be identified by text classifiers. This paper proposes a methodology with two strength measures for evaluating the appropriateness of candidate TC categories. The measures were tested on two alternative sets of candidate categories that were drafted for supporting construction field inspections. The results showed that the measures could accurately predict the relative TC performance and the satisfaction levels (satisfactory or unsatisfactory) of TC categories. Beyond the construction domain, this research provides a generalized procedure for evaluating the strength of candidate TC categories. (C) 2016 Elsevier B.V. All rights reserved.

Keywords

Accident Prevention; Classification; Construction Industry; Inspection; Occupational Safety; Standards; Text Classification Categories; Construction Field Inspection; On-site Accident Prevention; Violations; Safety Professionals; Construction Safety Standards; Candidate Tc Categories; Reference Applicable Standards; Information; Model; Construction Safety; Field Inspection; Text Classification