US EPA

This draft Geographic Information System (GIS) tool can be used to generate scenarios of housing-density changes and calculate impervious surface cover for the conterminous United States. A draft User’s Guide accompanies the tool. This product distributes the population projections and creates land use data described in the 2009 EPA report "Land-Use Scenarios: National-Scale Housing-Density Scenarios Consistent with Climate Change Storylines".

The GIS tool and its documentation, “ICLUS v1.2 GIS Tools and User's Manual: ArcGIS Tools and Datasets for Modeling US Housing Density” enables users to run a spatial allocation model (Spatially Explicit Regional Growth Model, SERGoM) with the population projections developed for the U.S. In 2009, EPA released a report describing the development of nationwide housing-density and impervious surface scenarios. The ICLUS (Integrated Climate and Land Use Scenarios) project uses demographic modeling as the basis for the housing-density scenarios. These scenarios are broadly consistent with global-scale, peer-reviewed storylines of population growth and economic development, which are used by climate change modelers to develop projections of future climate. Population at the county scale is placed as housing on the landscape using SERGoM v3 (Spatially Explicit Regional Growth Model).

The Geographic Information System (GIS) tool allows users to:

• replace the ICLUS projected population values to reflect different growth rate assumptions;
• customize housing density patterns by altering household size and travel time assumptions;
• summarize patterns by region, watershed, county, or NLCD 2001 land cover classes;
• reclassify housing density into classes different than those already provided; and
• generate a map of estimated impervious surface based on a housing density map.

The data consist of five population scenarios by county for the conterminous United States and are available by 5-year increments from 2000 to 2100. The population projections for each U.S. county drive the production of new housing units, which are allocated in response to the spatial pattern of previous growth (e.g., 1990 to 2000), transportation infrastructure, and other basic assumptions. The housing allocation model recomputes housing density in 10-year time steps.

The GIS tool enables users to run SERGoM with the population projections developed for the ICLUS project and allows users to modify the spatial allocation housing density across the landscape.

EPA will conduct an external peer usability review in Jan. 2010.

U.S. EPA. ICLUS Tools and Datasets (Version 1.2) and User's Manual: Arcgis Tools and Datasets for Modeling US Housing Density (External Review Draft). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-09/143, 2009.

Due to the large file sizes, please use the contact us form to request access to our FTP site to receive a copy of the GIS tool and documentation.