The SLVAirshed project team is building a system dynamics model that will enable researchers and decision-makers to explore the possible CO2 and trace gas emissions consequences of various alternative urban futures. You may view a draft conceptual diagram of the emerging model or download a text narrative of its major features. These documents are only drafts - the Salt Lake Valley "story" is continually evolving as we collect more data.

The core of the urban sprawl model is currently operational. "SprawlSim" simulates the dynamic interplay that exists between urban sprawl (represented by rapid growth in low density land area rather than clustered high density development), transportation (road lane mile) requirements, and road building policies. These interactions lead to a vicious cycle - building new roads to alleviate traffic congestion enables commuters to travel greater distances from the urban core to live in large houses on large lots, which in turn, leads to traffic congestion and increasing demand for more road lane miles. If new roads are built, the reduced traffic congestion induces more commuters to travel even greater distances to large houses on large lots. Currently, this model is tuned to the Salt Lake City-Ogden metropolitan area of northern Utah. With the SprawlSim model, the user can explore the implications of various urban planning policy options through the year 2030.

A recent paper by Phil Emmi (504 kb pdf) outlines the background for SprawlSim and illustrates the consequences of various alternative policies. Please consider experimenting with the internet-accessible version of SprawlSim. You must use Internet Explorer to use this interface.

We will update this webpage as additional modules, such as CO2 emissions and the urban carbon cycle, are added to the systems model.