About Dynamic Choropleth Maps

Description
Dynamic Choropleth Maps software is an interactive data visualization tool developed by the Office of Environmental Information to investigate multivariate environmental-health-demographic relationships in data using interactive, dynamic choropleth maps. Such a tool can be used to explore environmental indicators spatially and to allow one to interact with the data by varying the multi-dimensional components of the indicator, or index, and see the map change dynamically in real-time.

Intended Use
This tool was designed to visualize and dynamically interact with multi-dimensional data. Visual patterns or data relationships inferred by the user should be interpreted with care.

How Dynamic Choropleth Maps Work
Choropleth maps are one of the most commonly used means of displaying areal data. Choropleth maps color regions, or areas, according to data defined for that area. Dynamic Choropleth Maps software colors counties according to aggregations of data reported by Data Sources in the county. The Software is designed to allow the user to dynamically interact with the choropleth map by changing data views, zooming map scales and using the sliders to group and manipulate combinations of principal and secondary data and observe the interactions in real-time.

Data Sources
Dynamic Choropleth Maps uses five dimensions to visualize data. The first two dimensions are spatial, the other three are data drawn from data cubes of user selectable data elements. The software uses county as the geographic mapping unit, but other polygonal structures could be applied as well. Currently the software includes over a dozen data cubes on topics which include environmental, health, demographic, and economic data aggregated to the county level. The data come from a number of key sources, such as:

U.S. EPA: TRI, Air and Water Quality Data
Bureau of Census: Demographic Data
Bureau of Economic Analysis: Economic, Income Data
Bureau of Labor Statistics: Labor Data
Department of Transportation: Transportation data
National Cancer Institute: Cancer Mortality Data
USGS: Ground Water data
NOAA: Meteorology data

For detailed information on these data sources see Metadata.