Orange County NC Website
The ICLUS tools use a statistical model of urban <br />growth that is directly integrated with ArcGIS <br />and incorporates scenarios of housing density and <br />derived impervious surface cover based on the IPCC <br />social, economic, and demographic storylines (A1, <br />A2, 131, 132). The ICLUS outputs are derived from <br />a pair of models: a demographic model that gener- <br />ates population projections and a spatial allocation <br />model (SERGoM, Theobald 2005). Each scenario <br />is run for the conterminous United States, or for <br />smaller regions as specified by the user, projected <br />through 2100 by decade. Unlike some other model- <br />ing approaches, ICLUS uses projected population <br />growth to estimate future patterns of housing densi- <br />ty and captures a wider gradient of urban land use <br />(e.g. urban vs. rural) than is commonly captured in <br />the categories utilized in land cover data sets such as <br />the NLCD. These projections are based on derived <br />relationships from historic data. An example of the <br />output is shown in Figure 4 -5. This approach differs <br />from that utilized by other models such as SLEUTH, <br />which uses cellular automata to model emergent <br />behavior from a set of initial conditions and behav- <br />ioral rules. Cellular automata models are scale inde- <br />pendent, allowing local, regional and continental <br />Pboto: U.S. Global Change Research Program, 2009 <br />scale processes to be described in a single framework. <br />In the Southeast, the Biodiversity and Spatial Infor- <br />mation Center (BaSIC) is currently using SLEUTH - <br />R (Jantz et al. 2010) to model urban growth as part <br />of the "Designing Sustainable Landscapes" project <br />(DSL). The DSL Project uses vegetation and urban <br />dynamics modeling to examine the potential impacts <br />of landscape -level changes on the future capability <br />of habitats to support wildlife populations (BaSIC, <br />personal communication, www.basic.ncsu.edu /dsl). <br />A third approach is being used by researchers from <br />RENCI at UNC Charlotte (Renaissance Computing <br />Institute, http: / /renci.uncc.edu /) who were initial- <br />ly commissioned by the Open Space Protection <br />Collaborative to develop urban growth models for <br />more than 20 counties in the greater Charlotte <br />region. RENCI's model uses satellite imagery to <br />forecast future urban growth using logistic regression <br />models that are integrated with population -based <br />models of urbanization pressure. This work is being <br />expanded to include two- thirds of the state by the <br />end of 2011. <br />The urban growth model developed by UNC Char- <br />lotte has been used to look at potential conflicts <br />