Knowledge to Serve the City: Insights from an Emerging Knowledge-Action Network to Address Vulnerability and Sustainability in San Juan, Puerto Rico

This paper presents initial efforts to establish the San Juan Urban Long-Term Research Area Exploratory (ULTRA-Ex), a long-term program aimed at developing transdisciplinary social-ecological system (SES) research to address vulnerability and sustainability for the municipality of San Juan. Transdisciplinary approaches involve the collaborations between researchers, stakeholders, and citizens to produce socially-relevant knowledge and support decision-making. We characterize the transdisciplinary arrangement emerging in San Juan ULTRA-Ex as a knowledge-action network composed of multiple formal and informal actors (e.g., scientists, policymakers, civic organizations and other stakeholders) where knowledge, ideas, and strategies for sustainability are being produced, evaluated, and validated. We describe in this paper the on-the-ground social practices and dynamics that emerged from developing a knowledge-action network in our local context. Specifically, we present six social practices that were crucial to the development of our knowledge-action network: 1) understanding local framings; 2) analyzing existing knowledge-action systems in the city; 3) framing the social-ecological research agenda; 4) collaborative knowledge production and integration; 5) boundary objects and practices; and 6) synthesis, application, and adaptation. We discuss key challenges and ways to move forward in building knowledge-action networks for sustainability. Our hope is that the insights learned from this process will stimulate broader discussions on how to develop knowledge for urban sustainability, especially in tropical cities where these issues are under-explored

Do Rail Transit Stations Induce Displacement?

As the construction and usage of rail transit proliferates in cities across the world, concerns abound about impacts on surrounding neighborhoods – including gentrification and displacement. Los Angeles County has seen a massive rail transit buildout—from zero to 93 stations along six lines—in 25 years. This boom has led to a prevailing perception that Los Angeles’ rail transit development causes an influx of high-income residents and an outflow of low-income residents near rail stations.This policy brief summarizes research that tests this perception by answering the following questions related to rail transit and household moves: Do rail transit stations affect residential move rates in surrounding neighborhoods? And, if so, then are lower income or long-term residents disproportionally displaced from the neighborhood?View the NCST Project Webpag

Sustainability and Displacement: Assessing the Spatial Pattern of Residential Moves Near Rail Transit

Rail transit’s association with gentrification has been a presence in the public discourse for some time and Los Angeles is no different. There is a prevailing public perception that Los Angeles' recent boom in rail transit development causes an influx of high income residents and an outflow of low income residents near rail stations. The authors' research asks whether the presence of rail transit increases the outflow lower-income neighborhood residents. The authors use a unique dataset of tax filers in Los Angeles County to address this question. This database tracks the income and location of households across 21 years at a fine spatial scale. This analysis aggregates household data to provide station-area population out mobility rates for 35 rail station neighborhoods and 35 paired control neighborhoods along two Los Angeles Metro transit lines. Their sample consists of 15 stations along the Red/Purple subway line and 20 station along the Gold light rail line that opened between 1993 and 2013. The authors measure effects on four income brackets: below 30% of Area Median Income (AMI) (<$15,000 in 2013), 30-50$40,000 in 2013).View the NCST Project Webpag

Sustainability and Displacement: Assessing the Spatial Pattern of Residential Moves Near Rail Transit

Rail transit’s association with gentrification has been a presence in the public discourse for some time and Los Angeles is no different. There is a prevailing public perception that Los Angeles' recent boom in rail transit development causes an influx of high income residents and an outflow of low income residents near rail stations. The authors' research asks whether the presence of rail transit increases the outflow lower-income neighborhood residents. The authors use a unique dataset of tax filers in Los Angeles County to address this question. This database tracks the income and location of households across 21 years at a fine spatial scale. This analysis aggregates household data to provide station-area population out mobility rates for 35 rail station neighborhoods and 35 paired control neighborhoods along two Los Angeles Metro transit lines. Their sample consists of 15 stations along the Red/Purple subway line and 20 station along the Gold light rail line that opened between 1993 and 2013. The authors measure effects on four income brackets: below 30% of Area Median Income (AMI) (<$15,000 in 2013), 30-50$40,000 in 2013).View the NCST Project Webpag

The Joint Effects of Income, Vehicle Technology, and Rail Transit Access on Greenhouse Gas Emissions

This paper examines the relationship between income, vehicle miles traveled (VMT), and greenhouse gas (GHG) emissions for households with varying access to rail transit in four metropolitan areas—Los Angeles, the San Francisco Bay Area, San Diego, and Sacramento—using data from the 2010–2012 California Household Travel Survey. Daily vehicle GHG emissions are calculated using the California Air Resources Board’s 2014 EMFAC (emission factors) model. Two Tobit regression models are used to predict daily VMT and GHG by income, rail transit access (within or outside 0.5 miles of a rail transit station in Los Angeles and the Bay Area, and linear distance to rail in San Diego and Sacramento), and metropolitan area. Comparing predicted VMT and GHG emissions levels, this paper concludes that predicted VMT and GHG emission patterns for rail access vary across metropolitan areas in ways that may be related to the age and connectivity of the areas’ rail systems. The results also show that differences in household VMT due to rail access do not scale proportionally to differences in GHG emissions. Regardless, the fact that GHG emissions are lower near rail transit for virtually all income levels in this study implies environmental benefits from expanding rail transit systems, as defined in this paper

Do high income households reduce driving more when living near rail transit?

Transportation planning today requires an understanding of how income and near-rail residence jointly influence household travel behavior. This article fills a gap in the literature by showing how vehicle miles traveled (VMT) and transit trips taken (TT) vary with income and rail transit access by neighborhood type. Results indicate that, when comparing households with similar incomes and examining how the “near-rail” versus “far from rail” VMT and TT gap varies by income, the cross-sectional reduction in nominal VMT and the increase in TT on a percentage basis is generally larger for higher-income households (\u3e$50,000), and particularly so in neighborhoods dense with both jobs and population. These findings offer support for the notion that near-transit housing targeting higher-income households can have both sustainability and transit use benefits. We note, though, that equity considerations are a strong reason to include low-income housing near rail transit, and argue that policies focusing overly singly on either low-income or high-income housing near rail transit will not be as impactful as a robust focus on mixed-income housing developments in rail transit-oriented developments (TODs)

Synthesis of Household Yard Area Dynamics in the City of San Juan Using Multi-Scalar Social-Ecological Perspectives

Urban sustainability discourse promotes the increased use of green infrastructure (GI) because of its contribution of important ecosystem services to city dwellers. Under this vision, all urban green spaces, including those at the household scale, are valued for their potential contributions to a city’s social-ecological functioning and associated benefits for human well-being. Understanding how urban residential green spaces have evolved can help improve sustainable urban planning and design, but it requires examining urban processes occurring at multiple scales. The interaction between social structures and ecological structures within the subtropical city of San Juan, the capital and the largest city of Puerto Rico, has been an important focus of study of the San Juan ULTRA (Urban Long-Term Research Area) network, advancing understanding of the city’s vulnerabilities and potential adaptive capacity. Here we provide a synthesis of several social-ecological processes driving residential yard dynamics in the city of San Juan, Puerto Rico, through the evaluation of empirical findings related to yard management decisions, yard area, and yard services. We emphasize the role of factors occurring at the household scale. Results are discussed within the context of shrinking cities using an integrated, multi-scalar, social-ecological systems framework, and consider the implications of household green infrastructure for advancing urban sustainability theory