Chester is leading research efforts to develop an understanding of how urban systems have been deployed, frameworks for assessing their energy and environmental impacts, and strategies for transitioning infrastructure systems for twenty-first century needs. His goal is to develop the science for understanding how embedded infrastructure design enables the emergent behaviors that we often consider to be unsustainable, and for analyzing and breaking path dependencies that will aid in transitioning to lower energy and environmental impact futures. His graduate work through 2008 largely focused on transportation infrastructure and since then he has focused more broadly on the interface of infrastructure and urbanization processes. Approximately half of his work is focused on the assessment of transportation systems and the other half land use, water, and energy systems, including their interdependencies. He has begun studying the role that infrastructure plays in contributing to extreme heat events in the US Southwest. His long-term research goals are to advance our understanding of how urban infrastructure design should balance the life-cycle benefits and costs of integrated systems with sensitivity to social-equity, economic growth, and future climate-constraints.
Urban areas are vulnerable to extreme weather related events given their location, high concentration of people, and increasingly complex and interdependent infrastructure. Impacts of Hurricane Katrina, Superstorm Sandy, and other disasters demonstrate not just failures in built infrastructure, they highlight the inadequacy of institutions, resources, and information systems to prepare for and respond to events of this magnitude. The highly interdisciplinary and geographically dispersed Urban Resilience to Extremes Sustainability Research Network (UREx SRN) team will develop a diverse suite of new methods and tools to assess how infrastructure can be more resilient, provide ecosystem services, improve social well being, and exploit new technologies in ways that benefit all segments of urban populations. Starting with nine network cities (six continental U.S. and three Latin American, home to over 35 million residents) and expanding in future years, the vision of the UREx SRN is to co-produce the knowledge needed to promote resilient, livable cities in a future that will look very different from today. The extreme events that this project will focus on include urban flooding, coastal storms, regional droughts, and extreme heat waves. These events are already occurring with shocking frequency in U.S. and global cities. Infrastructure is viewed as an important line of defense against hazards and disasters, yet current urban infrastructure is aging and proving inadequate for protecting city populations. The UREx team will link SRN scientists, students, local practitioners, planners, industry, NGOs, and other stakeholders across >25 institutions and >70 collaborators to co-produce data, models, images, stories, and on-the-ground projects that show how a new resilient infrastructure can be developed. Infrastructure that is flexible, adaptable, safe-to-fail, socially equitable, and ecologically based will enhance urban resilience in the face of a higher incidence of extreme events, more culturally diverse communities, and continued urbanization pressures. Ultimately, the UREx SRN will help accelerate knowledge generation and application to encourage innovative strategies towards urban sustainability.
The Urban Resilience to Extremes Sustainability Research Network (UREx SRN) will develop a novel theoretical framework for integrating social, ecological, and technological system (SETS) dimensions for conceptualizing, analyzing, and supporting urban infrastructure decisions in the face of climatic uncertainty in a more holistic way. The primary research question is: how do SETS domains interact to generate vulnerability or resilience to extreme weather related events, and how can urban SETS dynamics be guided along more resilient, equitable, and sustainable trajectories? The foundation of the network is eight working groups (WG) who will work together to answer this question. Network activities include: assembling comparable datasets for the cities; doing advanced climate and hydrological modeling and downscaling; conducting comparative analyses; further developing the SETS conceptual framework; experimenting with new visualization and computation approaches for representing the data and the SETS framework; using these products in participatory modeling and scenario analysis for each city; and developing the science and practice for transitioning infrastructure to meet 21st century resilience and sustainability goals. Continual network and educational evaluation will allow realignment and adjustment of the work based on iterative assessments. The program will develop a suite of interactive educational activities spanning institutions across the network, and including local practitioners as well as university students and young professionals. Working Groups include integral educational, communications, and diversity-enhancing activities for graduate and post-doctoral fellows, early-career researchers, and city professionals aimed at developing a model for co-producing effective and robust decision-support tools and educating the next generation of scientists and practitioners to carry out this work. These programs are expected to be especially attractive to Hispanic students and practitioners due to the project's focus on understanding the increasing cultural and intellectual connections of the U.S. and Latin America.
The strategic goals of the UREx SRN are to: 1) Build a network of cities, institutions, and student, post-doctoral, and faculty researchers to explore resilience of cities to extreme weather related events; 2) Develop novel theoretical frameworks that express a vision of sustainable, integrated urban infrastructure that is flexible, adaptable, safe-to-fail, socially equitable, and ecologically based; 3) Work with practitioners and decision makers, as well as a cadre of graduate and post-doctoral fellows, to co-produce knowledge that facilitates data-driven visioning and ultimately transitions to a sustainable future for urban infrastructure and, by extension, the fabric of urban social-ecological-technological sustainability; and, 4) Create a model for incorporating assessment, learning, and adjustment in response to evaluative feedback in a large, transdisciplinary, multi-institutional, multi-national research network.
Vulnerability can take on many forms including immediate loss of critical resources, shortage of resources, and direct human health impacts. Understanding how climate change creates short-term vulnerability (e.g., equipment failure in extreme heat events) and long-term vulnerability (e.g., water shortage and rising ambient temperatures) can aid the US Navy to plan, deploy, and manage bases in both tactical and relief efforts.
Our work integrates power and water infrastructure modeling into an interactive modeling simulator-based training suite known as the Resilient Infrastructure Simulation Environment (RISE). That work supports the identification, adaptive response, and mitigation of cascading failures that are the result from complex interactions between interdependent infrastructures operating in planning mode or in real-time simulation. The proposed work will incorporate climate change modeling and infrastructure characterization of military bases to permit the US Navy and other DoD branches to design and implement more resilient military bases and procedures.
This work will (1) reveal how infrastructures are interdependent in US Military bases, (2) describe how the vulnerabilities in US Military base infrastructure are exacerbated by climate change, (3) enumerate how these vulnerabilities increase the potential of failure within individual infrastructures as well as cascades to other infrastructures, and (4) evaluate human-environmental-infrastructure interactions to refine and support decision-making to avoid conflict and increase stability. Strategies to reduce fossil fuel dependence are an example outcome of this work that is directly pertinent to conflict avoidance. This particular example also provides second- and third-order benefits that address DoD’s aggressive energy goals through increased mission capability, improved autonomy (mission duration), saved lives from reduced fuel transport, and reduced expenditures. The modeling suite will facilitate the identification of other synergistic and multiplicative opportunities for stakeholders.
Exposure to heat is a growing public health concern in many cities across the globe. In the US, Southwest cities have experienced increasing numbers of heat waves in the past few decades, and global climate models project significant increases in both the duration and intensity of these extreme events. Facing these challenges, very little is known about how people are exposed to heat during their day-to-day activities as they interact with urban infrastructure. To understand exposure, factors including the types of homes people live in (and whether they have and use air conditioning), their mobility choices, the quality of the infrastructure (e.g., shading, landscaping, and material choice), their work situation (e.g., air conditioned office versus outdoor worker), and their activity profiles must be considered. A systematic framework that any city can use to understand how people are exposed to heat and proactively mitigate risk is needed.
To create insight into how people are exposed to heat, this work will develop an Urban Activity Heat Simulation (UAHS) platform that will join (1) a model of residential and workplace exposure, (2) travel simulations for automobile use, public transit, and biking/walking, (3) urban infrastructure characteristics, (4) high-resolution urban climate data, and (5) a model of exposure thresholds. UAHS will be developed using Phoenix, Arizona and Los Angeles, California as case studies. Heat performance models for buildings will be combined with surveys of home and work activities to assess how people experience heat indoors. Using national and regional travel surveys combined with detailed travel models, simulations of how people move throughout cities will be developed. Downscaled climate models will be used to estimate present and future outdoor conditions in both cities. Information on infrastructure including materials, landscaping, and shading will also be used to develop estimates of outdoor exposure. Combining simulated exposures with health records will provide new insight into dangerous heat exposure profiles. The platform will be validated with in situ monitoring. UAHS will be developed with the goal of enabling any city to build upon the platform for their unique population and infrastructure.
We developed a simulation to estimate mobility impacts of transportation infrastructure outges due to climate change. Scenarios were developed using Arizona as a case study for bridge failures and roadway closings due to intense rainfall events and flooding.
This project will develop a sophisticated and in depth description of future demand, grid response, and vulnerability due to increased (and prolonged) heat events in Southern California Edison (SCE) territory under current and future climate scenarios. It will enable innovative grid management and operation strategies and will identify adaptation guidance. Ultimately, this research will prepare utilities, the State, and local governments to better prepare for the here-to-unknown (but inevitable) strain resulting from the demand in increased electricity consumption due to heat events caused by climate change. The project requires a multi-disciplinary team with unique skill sets, including those of climate scientists, energy experts, urban planners, geo-spatial experts, and civil engineers. The project will provide: » Downscaled global climate models of future extreme heat events in Los Angeles County; » A report on the expected electricity demand increases due to average temperature increases and extreme heat events under different climate scenarios; » A report of grid vulnerability, with suggestions for adaptation to guide future planning and investment; » GIS map visualizations of research findings and analysis, which will enhance local governments and SCE’s public outreach and stakeholder engagement. The maps and accompanying data will comply with PUC privacy guidelines and will be made available to the public; and, » Coordinated outreach and education public displays that protect privacy (and potentially more classified documents for the IOUs and the CEC).
The project will construct a new computer-based Resilient Infrastructure Simulation Environment (RISE) to allow individuals, groups (including students), and experts to test infrastructure network design configurations and crisis response approaches in three socio-technical infrastructure systems: electric power, water, and roadway networks. Researchers will link social and technical analysis with human subject research to discover the adaptive actions, ideas, and decisions that contribute to resilience. The project comprises of two major parts. In Part I (Modeling), researchers will identify the structure, dynamics (functionalities), and vulnerabilities of the networks that make up water, roadway, and electric power systems in Phoenix, AZ and Indianapolis, IN. Researchers will analyze the resulting US-based network models in conjunction with those from international partners in Asia, Australia, and Europe to learn and adapt global resilience principles . The results will be combined with belief networks to develop realistic decision models for the RISE. In Part II (Simulation), researchers will construct the RISE to study how different experts, stakeholders, individuals, and groups act in simulated decision scenarios. Through observation, researchers will identify the problem-solving and response strategies that result in resilient action, and thus understandthe organizational and social processes of sensing, anticipating, adapting, and learning.
Taken together, this project will result in two principal research outcomes: 1) a measureable, testable description of resilience that fuses social, behavioral, and engineered elements for infrastructure system design, and 2) improved resilience among the students, managers, stakeholders and other participants participating in the study. The new knowledge will help policymakers design effective strategies to make America's water, power, and road networks more resilient.
Western US regions are expected to experience more heat days, water shortages, intense precipitation events, forest fires, and increased peak power demands in the future. Desert regions are particularly vulnerable to future climate-induced environmental changes, given their scarce water resources and heavy reliance on thermoelectric power generation. As climate-related environmental events become more common, water and electricity managers will be either directly or indirectly exposed to vulnerabilities in the interdependent water-electricity systems. These vulnerabilities may arise because the infrastructures were designed for a climate and demand profile that may be significantly different than what will be experienced in the coming decades, and because the institutions that manage the systems do not yet have anticipatory governance structures that would enable them to proactively address the future. This project will develop a framework for assessing coupled water and electricity infrastructure-institution vulnerability at cross-scales to future climate events. It will create an educational game for infrastructure managers to learn how to anticipate future vulnerable states of the infrastructure and proactively deploy physical and institutional changes that will improve the resilience of the coupled systems.
While research has studied the interdependencies between water and electricity infrastructure, little is known about how the vulnerability in one system may propagate to the other, and especially about how the operational governance structures of these systems should be adapted for a climate-constrained future. There is a need to better understand how the governing of water and electricity services from the regional to the local level can be coordinated to proactively reduce future climate vulnerability. Using Arizona as a case study, this project will develop (1) a cross-scale (subsystem to the region) model of the water and electricity systems, (2) an institutional assessment that includes infrastructure managers, decision makers, and policies that control or impact each component of the water and electricity infrastructure, and (3) an extreme climate vulnerability assessment that joins physical infrastructure characteristics with the institutional processes that govern them. With this coupled infrastructure-institutional vulnerability assessment we will (4) develop a learning game for infrastructure managers to both teach them about the vulnerabilities in the coupled infrastructure and also help them understand how their institutional structures can be proactively changed to improve systemwide resilience. Through a series of workshops with infrastructure managers from the US Southwest, we will (5) test the game and also facilitate visioning and scenario analysis exercises. We will create new knowledge and methods for assessing water and electricity systems that acknowledges that failure can propagate through complex systems and can start with vulnerabilities in both physical and institutional infrastructure. We will then explore how novel game-based learning approaches can provide researchers and infrastructure managers with knowledge of the complex system and an understanding of the strategies that are needed to create anticipatory governance for a climate-constrained future.
During the project, we will convene infrastructure managers to not only test our game but to also participate in visioning and case study exercises, and using this knowledge create an educational platform for the public, technical workforce, and university students. The learning game will ultimately be deployed to a publicly available website and a series of sustainable infrastructure transitions guidance documents will be developed for municipal water and electricity, agricultural water, and power generation users and organizations. We will then create a platform for anticipatory governance of climate vulnerabilities by creating a forum program for the Arizona Science Center, build communication tools for community leaders and engineering/technical workforces, and a curriculum for university students. Ultimately, we view the research as an important first step for identifying how next generation sustainable infrastructure should be deployed and managed. As such, we anticipate that the findings will have broad appeal to academics and infrastructure managers not only in the US but also internationally..
We developed a multi-criteria decision analysis framework and decision support spreadsheet to assistant transportation agencies in decision making for climate change. The framework and spreadsheet were developed using Interstate 10 in Arizona as a case study but are broadly applicable. Different infrastructure strategies to protect against heat and flooding were analyzed.
Door-to-door trips often consist of multiple modes of travel and there has been little insight to-date of the greenhouse gas implications of driving to or from transit. We developed an environmental life cycle assessment of multi-modal trip travel in the Los Angeles metropolitan region to characterize emissions from door-to-door travel.
For final results, see:
Greenhouse Gas and Air Quality Effects of Auto First-Last Mile Use With Transit, Chris Hoehne and Mikhail Chester, Transportation Research Part D, 2017, 53, pp. 306-320, doi: 10.1016/j.trd.2017.04.030.
The vulnerability to heat of urban Southwest populations is a combination of social and built environment (infrastructure) factors. To date, heat vulnerability research has largely been focused on social factors (including age, chronic disease, poverty level, and English proficiency, among others) and few studies have considered how infrastructure enables or restricts access to cooling. New methods are needed for i) categorizing and quantifying the significance of infrastructure systems in providing protection from heat, and ii) joining social and infrastructure vulnerability to heat indices into a single framework that will allow city agencies to prioritize investments.
The Southwest is expected to experience more heat days and water shortages in the future which magnifies the need to characterize the vulnerability of population subgroups to heat events as a function of both socio-demographic and built environment characteristics. Social vulnerability analysis has provided valuable insight into the socio-demographic factors that put communities at risk during heat events, but little is known about how infrastructure systems amplify vulnerability. Building construction practices, home air conditioning, electricity generation and transmission, and cooling centers can contribute to a community’s heat-related vulnerability. This project will develop methods for joining social and built environment vulnerability into a single framework, and will create a prioritization framework for selecting investments in cooling infrastructure that maximize the reduction in vulnerability across two Southwest counties: Los Angeles and Maricopa (Phoenix metro area).
The proposed integrated social and infrastructure vulnerability framework will produce novel methods for estimating the additional risk to heat that result from built environment characteristics, and will identify efficient cooling infrastructure investment strategies for reducing this risk. The project will focus on two urban areas that are highly vulnerable to heat, with large socio-economic disparities, immigrant communities, linguistic isolation, and increasingly uncertain water supplies, as well as very different infrastructure (Los Angeles grew largely between 1940-1980 and Phoenix from 1980 on). (a) Environmental, social, and infrastructure vulnerability indices will be developed. The infrastructure indices will include building shell analysis, home air conditioning, electricity generation and transmission, and cooling centers, at a census tract resolution. (b) The indices will be joined to create a socio-technical vulnerability index (STVI). (c) The STVI will weigh the infrastructure vulnerability indexes against the social and each other to account for the relative impacts of infrastructure services on morbidity and mortality outcomes, using two approaches for weight estimation: regression and stochastic assessment. The use of two approaches will provide the research team with an opportunity to i) assess the feasibility of developing infrastructure index weightings from existing urban built environment and morbidity/mortality data and ii) develop novel stochastic weighting methods for cities when low quality data exist to assess the likelihood that one infrastructure characteristics is more or less significant than another. (d) The weighted STVI index will be used to develop a framework for assessing how cities should prioritize infrastructure investments by considering building weatherization, air conditioning rebates, rooftop solar, tree planting, and cooling center placement. (e) The STVI and prioritization strategies for Los Angeles and Maricopa will be compared to understand the socio-demographic and built environment differences between each county and identify the key drivers that other cities should focus on.
Infrastructure are our front line of defense against climate change yet recent events reveal the vulnerability of these critical systems to climate change and extreme events. We are developing insight into why infrastructure are vulnerable to climate and hydrological hazards, identifying failure mechanisms, modeling infrastructure performance into a climate-impacted future, and characterizing how vulnerabilities can propogate across systems.
We are developing frameworks for integrating infrastructure analysis, life cycle assessment, and behavioral analysis for coupled transportation and land use assessment. As cities consider strategies for reducing the energy and environmental intensity of urban activities, new methods are needed for coupling infrastructure investments with behavioral changes. We are joining life cycle assessment with behavioral assessment to understand how the investment in new transit infrastructure or neighborhood redevelopment results in upfront cost and environmental impacts (e.g., in the construction of a building or light rail system) but long run economic and environmental benefits from activity changes (such as less automobile travel and lower household energy use). Using new transit systems in Phoenix and Los Angeles as case studies, we have developed an integrated transportation and land use life cycle assessment (ITLU-LCA) framework.
Infrastructure design and decisions can significantly impact the behaviors and activities in cities. The hard infrastructure systems that dominate land use and supply critical services are the result of decades, sometimes centuries, of decisions. While these systems have been the foundation on which tremendous growth and value has taken place, as we become more aware of the environmental and social consequences of cities, a better understanding is needed of how we can redesign these systems for twenty-first century goals. Using Phoenix and Los Angeles as case studies, we have developed historical growth models for roadways, parking and buildings. We connect this growth with information on how the infrastructure was used and identify patterns in the relationship between infrastructure and behavior to help cities rethinking future infrastructure investment.
Frameworks for the environmental life cycle assessment of transportation systems have become critically important as new vehicle technologies and alternative energy pathways develop. Traditionally, impacts from transportation systems have been associated with the operational effects of vehicles. As our knowledge of the complexity of transportation systems grows and policies and decisions take hold to reduce the impacts of mobility, broader thinking is needed for transportation services. We have developed a life cycle assessment framework for transportation services that includes infrastructure (construction, operation, and maintenance), vehicles (manufacturing and maintenance), energy production, and supply chain effects, in addition to propulsion. We have used this framework to assess a variety of systems and policies and show how life cycle thinking can provide unique information to a multitude of stakeholders.
Environmental LCA of Passenger Transportation Modes in the United States
Extensive infrastructures and supply chains support transportation services in the US and these systems produce significant environmental effects in the life cycle of passenger modes. We develop a framework for assessing infrastructure, vehicles, energy production, and supply chains, in addition to vehicle propulsion, for typical United States modes (autos, buses, heavy rail, light rail, and aircraft).
Regional Transportation LCA
We extend the aforementioned framework to major metropolitan areas in the United States to assess the regionalized life cycle effects of passenger transportation services. Using travel surveys and local infrastructure data, the life cycle energy use and air emissions of cities can be estimated.
Long-distance Transportation: High-speed Rail and Future Auto and Air Travel
Intercity passenger travel is dominated by automobile and air modes and the introduction of high-speed rail creates an opportunity for reducing long-distance transportation environmental impacts. The deployment of new long-distance transportation modes such as high-speed rail may require significant infrastructure investment which results in environmental impacts. Over time, however, the adoption of these new modes produces an opportunity for significantly reducing the environmental impacts of long-distance travel. Using the life cycle assessment framework, the deployment of high-speed rail in California is assessed against future improvements in aircraft engine performance and emerging automobile technologies.
Across the United States there is strong interest in high-capacity transit investment and the planning for new transit modes is often positioned to help meet energy reduction and environmental goals. Urban high-capacity transit systems provide opportunities for shifting travelers from automobiles, can induce demand for biking and walking, and can create opportunities for land use redevelopment. In cities across the United States including Boston, Chicago, New York, Phoenix, Los Angeles, and San Francisco, we are developing life cycle assessment methods for assessing the long-term effects of public transit investment.
Electric and Hybrid Vehicles
The life cycle impacts of electric vehicles is dependent on several critical factors (including battery size, battery energy density, charging mix, and technology use behavior) and the monetization of changes in damages from air pollution across the life cycle offers an opportunity to evaluate emerging technologies in a consistent impact assessment framework. With researchers at Carnegie Mellon University, we develop such a framework and use it to identify the confluence of technological characteristics that are needed to produce a reduction of public health, climate change, and oil displacement costs from electric vehicles.
Freight activities are a major portion of a region's energy use and environmental impacts, are central to economic activity, and have unique characteristics (long-distance, long vehicle lifetimes, and intra-region behavior) that, in sum, require unique strategies for reducing impacts.
Life Cycle Assessment of Goods Movement in California
An energy consumption and air emissions life cycle assessment that includes vehicle (manufacturing and maintenance), infrastructure (construction, operation, and rehabilitation), and energy production, in addition to propulsion, is developed for truck, rail, and ocean going vessel travel associated with California. The project was sponsored by the California Air Resources Board's through their T-6 Measure to reduce freight emissions for the state's Assembly Bill 32 greenhouse gas goals. The potential for mode shifting and alternative vehicles and fuels is considered and a California freight life cycle assessment framework is developed.
Prioritizing Strategies for Reducing Vehicle Emissions at the Mariposa Point of Entry
The Mariposa Point of Entry at the Arizona-Mexico border is a critical infrastructure for inspecting passenger and freight vehicles. While there have been major infrastructure upgrades, there remains significant opportunities for reducing air emissions at the port. Infrastructure, technology, and logistical strategies are developed for passenger and freight vehicles to reduce emissions as part of a US Environmental Protection Agency grant.
Cities are complex systems that take in resources, produce desirable and undesirable products, accumulate resources, and output waste. The interdependencies of infrastructure systems and growing city supply chains raises important questions about the sustainability of metropolitan regions. Urban Metabolism is a systems-oriented framework for assessing the flows of resources in to and out of cities. Through several projects (including the assessment of the water-energy nexus in Arizona, transportation energy use in Phoenix, and resource use in Los Angeles), we are creating new methods for analyzing resource use and its impacts, at high spatial and temporal resolutions, using emerging rich datasets from cities.