Urban form, land use patterns, and the type of structures significantly influence a city's energy needs, and consequently, its greenhouse gas (GHG) emissions. Engineering and design of urban form is an important strategy for managing climate change and other environmental impacts of energy, as well as being key to the livability of cities. This project aims to clarify connections between urban form and use and energy use in the built environment (buildings and paved surfaces) and transport. Specific research questions addressed are:

• How do different urban forms and patterns of land use contribute to energy use and GHG emissions?
• How does urban energy use and GHG emissions evolve as a community changes over time?
• How do socioeconomic characteristics of the population influence these patterns of land use and travel behavior together with their implications for energy and emissions?

These questions are addressed by building a networked infrastructure model which represents the life cycle energy use of buildings and transport by mapping energy use in travel analysis zones (TAZ) to a spatial network connected according to residents' travel between TAZs for different purposes. For example, retail building energy use for an area becomes a distributed network according to where residents are travelling for shopping trips. The model tracks dynamics through building a retrospective time series, through which the evolution of the network of energy use as an area develops can be tracked. The model accounts for life cycle impacts in that construction/manufacture, operation and end-of-life of buildings, roads and vehicles are included.

The model is implemented through case studies of two Phoenix sub-areas, one in downtown Phoenix, which is undergoing redevelopment towards higher density housing and the second, a low-density suburban area at the edge of Phoenix which has undergone significant growth in the last two decades.

The research proposes a new network model that integrates neighborhood growth, transportation, and life cycle assessment models to address questions of contemporary interest in urban infrastructure systems. The innovation proposed here is to view building infrastructures as a spatial network mediated through usage via transportation systems. In addition the proposal to study dynamics of the network through evolutionary longitudinal data could yield insights into urban system design. Longitudinal analysis has been rarely used in researching the impact of land use on travel behavior. While the modeling approach is explored through case studies in Phoenix, it can be broadly applied to urban areas around the world. The vision for this model is part of an evolutionary process to develop systems tools to better understand and manage the complexity of urban systems to enhance its sustainability.

The research engages research students, researchers and urban planners through a portfolio of outreach activities. An international partnership with the Technical University of Kaiserslautern, Germany, extends the international scope of impacts. Activities include development of a visualization tool, integration of material into university curricula and workshops that include urban planners and city leaders. To understand complex networks the project team will develop a visualization tool to enhance research and communication. At the university level, students are reached directly through incorporation into courses in the School of Sustainability and the School of Sustainable Engineering at Arizona State University. A broader group of students and faculty in the U.S. and abroad are reached through development of online modules and dissemination through the Center for Sustainable Engineering and the Technical University, Kaiserslautern, Germany. Urban planners and urban policy makers are engaged through workshops to be held in Phoenix and Kaiserslautern.