Case Study:

Envision Utah

Methodology

Land Use

The land use analysis was performed by QGET technical staff based on GIS data, economic and demographic forecasts, local plans, and input from local officials and the public. The analysis considered both the design (allocation of population and employment) and the characteristics (amount of infill/redevelopment, total land consumed, population and employment density, housing types, and proximity measures) of the baseline and three alternative scenarios. Rather than simply shifting population and employment among zones, the land use analysis was conducted through an extensive process in which development by type and characteristic was assigned to 50.3-meter grid cells within the GIS environment. A number of land use-related layers were used, in conjunction with local plans and feedback from local officials and the public, to develop a realistic allocation of future development under different scenarios. Despite the detailed spatial scale of the analysis, its purpose was not to identify specific areas that would be developed, but rather to determine a realistic allocation of future development in order to measure overall regional impacts for each scenario.

The land use analysis included the following steps:

1. Incorporation of input from regional design workshops, including the amount and density of development by type under each scenario, as well as realistic expectations for future development by geographic area;
2. Development of the "constrained and developed" land mask, to identify undevelopable and developable land;
3. Allocation of new development. Increments of various densities/types were added to developable land, consistent with control totals and the characteristics of each scenario; and
4. Evaluation of the land use characteristics of each of the scenarios. Land use measures included total land consumption, level of infill/redevelopment, densities, housing types, population with access to rail transit, and loss of agricultural lands.

To create the constrained and developed land mask, lands that were considered unbuildable due to environmental or safety concerns were removed, as were existing developed lands. These were merged to form a composite mask of land not available for development. The remaining available land was then used to accommodate development based on the parameters of the four scenarios. Unavailable land could be considered available for future development if it met the criteria for potential redevelopment and infill development, which varied for each scenario. The process for developing the land use mask and allocating development in each of the scenarios is described in more detail in Utah (1999).

Once future land development by type was allocated spatially, the incremental growth was combined with the existing developed grid to calculate total developed land area. The final product became a virtual city in a grid structure, containing households, employment and other information distributed across the landscape of the Greater Wasatch area in different patterns.

The land use analysis was conducted by Fregonese Calthorpe and Associates and the State of Utah's Automated Geographic Reference Center.

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