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Department: Urban Design and Planning

Utilizing Fractal Dimensions as Indicators to Detect Elements of Visual Attraction: A Case Study of the Greenway along Lake Taihu, China

Fan, R., Yocom, K. P., & Guo, Y. (2023). Utilizing Fractal Dimensions as Indicators to Detect Elements of Visual Attraction: A Case Study of the Greenway along Lake Taihu, China. Land (Basel), 12(4), 883–. https://doi.org/10.3390/land12040883

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Abstract

It is widely acknowledged that the quality of greenway landscape resources enhances the visual appeal of people. While most studies have evaluated visual perception and preference, few have considered the relationship between the distribution of greenways in relation to the proximity of water bodies such as lakes and rivers. Such an investigation requires an in-depth analysis of how to plan and design greenways in order to better enhance people's willingness to access and utilize them. In this research we propose specific color brightness and contour visual attraction elements to further discuss the quality of greenway landscape resources in the rapidly urbanizing Lake Taihu region of China. Specifically, we utilize a common method in fractal theory analysis called counting box dimension to calculate and analyze the sample images. The method generates data on fractal dimension (FD) values of two elements; the optimal fractal dimension threshold range; the characteristics exhibited by the maximum and minimum fractal dimension values in the greenway landscape; and the relationship between the two visual attraction elements allowing us to derive distribution of the greenway and water bodies. The results reveal that greenway segments with high values of the visual attraction element of color brightness fractal dimension (FD) are significantly closer to the lake than those subject to high values of the visual attraction element. Some segments are even close to the lake surface, which is because the glare from the direct sunlight and the reflection from the lake surface superimposed on each other, so that the greenway near the lake surface is also affected by the brightness and shows the result of high color brightness values. However, the greenway segments with high values of contour element FD are clearly more influenced by plants and other landscape elements. This is due to the rich self-similarity of the plants themselves. Most of the greenway segments dominated by contour elements are distant from the lake surface. Both color brightness and contour elements are important indicators of the quality of the visual resources of the Lake Taihu Greenway landscape. This reveals that the determination of the sub-dimensional values of color brightness (1.7608, 1.9337) and contour (1.7230, 1.9006) visual attraction elements and the optimal threshold range (1.7608, 1.9006) can provide theoretical implications for the landscape planning and design of lake-ring type greenways and practical implications for assessing the quality of visual resources in greenway landscapes.

Keywords

color brightness; contour; visual attraction; fractal dimension (FD); boxplot; Lake Taihu

Population Health Initiative awards College of Built Environments researchers a spring quarter 2023 Tier 1 pilot grant

The Population Health Initiative announced the award of nine Tier 1 pilot grants to interdisciplinary research teams representing 10 of the University of Washington’s schools and colleges. The total award value of these grants is nearly $210,000, which includes school, department and unit matching funds. Read more in the CBE Story here. “We were extremely pleased with the range of challenges these awards will work to address,” said Ali H. Mokdad, the UW’s chief strategy officer for population health and professor of…

College of Built Environments Faculty and Student receive Husky Sustainability Awards 2023

The Husky Sustainability Awards recognize individuals and groups across all University of Washington campuses who lead the way for sustainability at the University of Washington. This is the 14th year awards have been given by the UW Environmental Stewardship Committee. The Husky Sustainability Awards are given to students, faculty and staff from the Seattle, Bothell and Tacoma campuses who show impact, initiative, leadership and dedication around sustainability. Congratulations to the recipients from the College of Built Environments, who are listed below….

Time-Varying Food Retail and Incident Disease in the Cardiovascular Health Study

Lovasi, G. S., Boise, S., Jogi, S., Hurvitz, P. M., Rundle, A. G., Diez, J., Hirsch, J. A., Fitzpatrick, A., Biggs, M. L., & Siscovick, D. S. (2023). Time-Varying Food Retail and Incident Disease in the Cardiovascular Health Study. American Journal of Preventive Medicine, 64(6), 877–887. https://doi.org/10.1016/j.amepre.2023.02.001

Does Compact Development Mitigate Urban Thermal Environments? Influences of Smart Growth Principles on Land Surface Temperatures in Los Angeles and Portland

Won, Jongho, and Meen Chel Jung. 2023. Does Compact Development Mitigate Urban Thermal Environments? Influences of Smart Growth Principles on Land Surface Temperatures in Los Angeles and Portland. Sustainable Cities and Society 90.

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Abstract

The smart growth paradigm has emerged as a major planning framework to respond to the adverse outcomes of reckless development, but its influences on urban thermal environments are underexplored in the scholarly literature. Since elevated land surface temperature (LST) is closely related to the physical expansion of developed areas, it is necessary to identify the effects of smart growth strategies on LST. This study, therefore, investigated the relationships between LST, landscape variables, and smart growth variables at the census block group level in two distinct urban locales: the City of Los Angeles, California, and the City of Portland, Oregon, from 2010 to 2018. Through multivariate analyses—including the principal component analysis (PCA), K-means clustering, analysis of covariance (ANCOVA), and regression models—this study revealed the potential of urban forms promoted by the smart growth principles comprehensively to mitigate LST. Given the different features of built environments and planning systems between the two cities, the results of this study also indicate the necessity of considering local contexts rather than suggesting a “one-size-fits-all” policy.

Keywords

Smart growth; Compact development; Land surface temperature; Urban form; Landscape

Say Where You Sample: Increasing Site Selection Transparency in Urban Ecology

Dyson, Karen; Dawwas, Emad; Poulton Kamakura, Renata; Alberti, Marina; Fuentes, Tracy L. (2023). Say Where You Sample: Increasing Site Selection Transparency in Urban Ecology. Ecosphere, 14(3).

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Abstract

Urban ecological studies have the potential to expand our understanding of socioecological systems beyond that of an individual city or region. Cross-comparative empirical work and synthesis are imperative to develop a general urban ecological theory. This can be achieved only if studies are replicable and generalizable. Transparency in methods reporting facilitates generalizability and replicability by documenting the decisions scientists make during the various steps of research design; this is particularly true for sampling design and selection because of their impact on both internal and external validity and the potential to unintentionally introduce bias. Three interdependent aspects of sample design are study sample selection (e.g., specific organisms, soils, or water), sample specification (measurement of specific variable of interest), and site selection (locations sampled). Of these, documentation of site selection—the where component of sample design—is underrepresented in the urban ecology literature. Using a stratified random sample of 158 papers from 12 major urban ecology journals, we investigated how researchers selected study sites in urban ecosystems and evaluated whether their site selection methods were transparent. We extracted data from these papers using a 50-question, theory-based questionnaire and a multiple-reviewer approach. Our sample represented almost 45 years of urban ecology research across 40 different countries. We found that more than 80% of the papers we read were not transparent in their site selection methodology. We do not believe site selection methods are replicable for 70% of the papers read. Key weaknesses include incomplete descriptions of populations and sampling frames, urban gradients, sample selection methods, and property access. Low transparency in reporting the where methodology limits urban ecologists' ability to assess the internal and external validity of studies' findings and to replicate published studies; it also limits the generalizability of existing studies. The challenges of low transparency are particularly relevant in urban ecology, a field where standard protocols for site selection and delineation are still being developed. These limitations interfere with the fields' ability to build theory and inform policy. We conclude by offering a set of recommendations to increase transparency, replicability, and generalizability.

Keywords

external validity, field ecology, generalizability, internal validity, replication, reproducibility, sampling design, site selection, theory building, transparency

Designing Bike-Friendly Cities: Interactive Effects of Built Environment Factors on Cycling

Wang, Lan, Kaichen Zhou, Surong Zhang, Anne Vernez Moudon, Jinfeng Wang, Yong-Guan Zhu, Wenyao Sun, Jianfeng Lin, Chao Tian, and Miao Liu. 2023. “Designing Bike-Friendly Cities: Interactive Effects of Built Environment Factors on Cycling.” SSRN Electronic Journal.

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Abstract

Geographical detector models facilitate a comprehensive approach to urban Design. • Interaction detector measures combined effects of the built environment on Cycling. • Street network centrality has the largest explanatory power on cycling. • A sense of enclosure defined by streetscape elements encourages cycling. Designing bike-friendly cities could promote health and mitigate climate change. Most studies of the association between the built environment and cycling used the "5Ds" framework and linear modeling. However, the built environment exerts complex influences on travel behavior. To better inform urban design for cycling, this study employed geographical detector models that quantify the explanatory power of individual and interactively paired built environment factors on bike-sharing. Data came from 6.5 million bike-sharing orders in Shanghai. Expectedly, we found that street network centrality and important facilities like supermarkets and libraries have the greatest independent and interactive effects. More surprisingly, streetscape elements, including sky view and building frontage, offered significantly higher explanatory power when paired with each other or with street network centrality and important facilities. By identifying the overlooked interactive effects of urban environment factors, the study provides guidance for urban designers to consider combinations of factors that effectively promote cycling. [ABSTRACT FROM AUTHOR]

Keywords

Bike-friendly city; Cycling; Street view images; Urban design

Coastal Adaptations with the Shoalwater Bay Tribe: Centering Place and Community to Address Climate Change and Social Justice

The proposed community-based participatory action research project is a collaborative research, planning and design initiative that will enable a UW research team to work with the Shoalwater Bay Indian Tribe to explore sustainable and culturally relevant strategies for an upland expansion in response to climate change-driven sea level rise and other threats to their coastal ecosystems and community. The situation is urgent as the reservation is located in the most rapidly eroding stretch of Pacific coastline in the US, on near-sea-level land vulnerable also to catastrophic tsunamis. The project will advance the Tribe’s master plan and collaboratively develop a model of climate adaptive, culture-affirming and change-mitigating environmental strategies for creating new infrastructure, housing and open spaces in newly acquired higher elevation land adjacent to the reservation. Design and planning strategies will draw on culturally-based place meanings and attachments to support a sense of continuity, ease the transition, and create new possibilities for re-grounding. Sustainable strategies generated by the project will draw on both traditional ecological knowledge and scientific modeling of environmental change. The project will involve the following methods and activities:

  • The creation of a Tribal scientific and policy Advisory Board with representatives from the Tribal Council, elder, youth, state and county agencies, and indigenous architects and planners;
  • Student-led collaborative team-building and research activities that will also engage Tribal youth;
  • Systematic review of the Tribe’s and neighboring county plans;
  • Interviews, focus groups and community workshops to identify priority actions, needs and strategies;
  • Adaptation of existing research on sustainable master planning, design and carbon storing construction materials; and
  • The development of culturally meaningful and sustainable building prototypes.

Deliverables include a report of findings summarizing community assets and values, and priorities for the upland expansion vetted by Tribal leaders, documentation and evaluation of the UW-community partnership and engagement process, digitized web- based geo-narratives and story maps and technical recommendations for culturally-informed schematic designs, sustainable construction methods and low-embodied carbon storing materials. The project process and outcomes will have broad applicability for other vulnerable coastal communities and can be used to support their climate adaptation efforts as well.

Research Team
Principal Investigator: Daniel Abramson, College of Built Environments, Urban Design and Planning, University of Washington
Community Lead: Jamie Judkins, Shoalwater Bay Indian Tribe

University of Washington Partners:
Rob Corser, Associate Professor, Department of Architecture
Julie Kriegh, Affiliate Lecturer, Departments of Construction Management and Architecture and Principal, Kriegh Architecture Studios | Design + Research
Jackson Blalock, Community Engagement Specialist, Washington Sea Grant
Lynne Manzo, Professor, Department of Landscape Architecture
Kristiina Vogt, Professor, School of Environmental and Forest Sciences

Community Partners:
Daniel Glenn, AIA, NCARB, Principal, 7 Directions Architects/Planners 
John David “J.D.” Tovey III, Confederated Tribes of the Umatilla Indian Reservation
Timothy Archer Lehman, Design and Planning Consultant and Lecturer

An Interdisciplinary Agent-Based Evacuation Model: Integrating the Natural Environment, Built Environment, and Social System for Community Preparedness and Resilience

Chen, Chen; Koll, Charles; Wang, Haizhong; Lindell, Michael K . 2023. “An Interdisciplinary Agent-Based Evacuation Model: Integrating the Natural Environment, Built Environment, and Social System for Community Preparedness and Resilience.” Natural Hazards and Earth System Sciences 23 (2).

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Abstract

Previous tsunami evacuation simulations have mostly been based on arbitrary assumptions or inputs adapted from non-emergency situations, but a few studies have used empirical behavior data. This study bridges this gap by integrating empirical decision data from surveys on local evacuation expectations and evacuation drills into an agent-based model of evacuation behavior for two Cascadia subduction zone (CSZ) communities that would be inundated within 20–40 min after a CSZ earthquake. The model also considers the impacts of liquefaction and landslides from the earthquake on tsunami evacuation. Furthermore, we integrate the slope-speed component from least-cost distance to build the simulation model that better represents the complex nature of evacuations. The simulation results indicate that milling time and the evacuation participation rate have significant nonlinear impacts on tsunami mortality estimates. When people walk faster than 1 m s -1 , evacuation by foot is more effective because it avoids traffic congestion when driving. We also find that evacuation results are more sensitive to walking speed, milling time, evacuation participation, and choosing the closest safe location than to other behavioral variables. Minimum tsunami mortality results from maximizing the evacuation participation rate, minimizing milling time, and choosing the closest safe destination outside of the inundation zone. This study's comparison of the agent-based model and the beat-the-wave (BtW) model finds consistency between the two models' results. By integrating the natural system, built environment, and social system, this interdisciplinary model incorporates substantial aspects of the real world into the multi-hazard agent-based platform. This model provides a unique opportunity for local authorities to prioritize their resources for hazard education, community disaster preparedness, and resilience plans. [ABSTRACT FROM AUTHOR]

 

US Pacific Coast Communities’ Past Preparedness and Preparedness Intentions for Cascadia Subduction Zone Tsunamis

Lindell, Michael K., Meen Chel Jung, Carla S. Prater, and Donald H. House. 2023. “US Pacific Coast Communities’ Past Preparedness and Preparedness Intentions for Cascadia Subduction Zone Tsunamis.” International Journal of Disaster Risk Reduction 84.

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Abstract

This study examined tsunami awareness and preparedness by 225 respondents in three communities exposed to Cascadia Subduction Zone (CSZ) tsunamis. Some participants viewed a tsunami brochure, but all participants reported their degree of information sufficiency about tsunamis and protective actions to take when a tsunami threatens, expected warning sources for local and distant tsunamis, past preparedness actions and preparedness intentions, tsunami experience, past tsunami information, perceived tsunami zone, and demographic characteristics. In addition to the results showing that the brochure had a significant positive effect on tsunami information sufficiency and expected warning sources, the latter two variables affected intentions to engage in future preparedness actions. In addition, tsunami experience, past tsunami infor-mation, and past preparedness also affected these variables. Although psychological responses were significantly related to preparedness intentions, they were not related to hypothesized antecedent variables-tsunami experience, past preparedness, past information, and de-mographic characteristics. The data suggest that emergency managers can promote tsunami hazard education by distributing comprehensive tsunami brochures, but should also work with local news media to direct CSZ residents to agency web sites where they can access additional information about tsunami hazard, expected warning sources, appropriate preparedness, and response actions.

Keywords

Cascadia subduction zone tsunamis; Risk communication; Tsunami hazard awareness; Tsunami preparedness