The Virginia Development Vulnerability Model quantifies the predicted relative risk of conversion from "natural", rural, or other open space lands to urbanized or other built-up land uses. It is presented as a raster data set and associated maps, in which the relative vulnerability of lands ranges from 0 (not developable) to 100 (most vulnerable). Cells in which development has already occurred are coded as 101.
The current version of the model is based on travel times to several development "attractors": urban areas, metropolitan areas (a subset of urban areas), and imperviousness growth hotspots. It also incorporates the legal protection status and biological management intent of conservation lands in the state. The model is based in part on the most recent imperviousness data available from the National Land Cover Database (NLCD), and thus represents landcover conditions circa 2011. The model will be updated periodically as new data representing more recent conditions become available. A future, more complex version of the model is currently under development. It will incorporate a wider array of predictor variables representing various driving forces of development, and will employ a rigorous statistical analysis to derive the relative probability of development.
The Virginia Development Vulnerability Model is one of several in a suite of conservation planning and prioritization models developed by the Virginia Natural Heritage Program and partners, known collectively as Virginia ConservationVision. The vulnerability model can be used in conjunction with other data to help prioritize lands for immediate protection. The model can also serve as an input for simulating future land cover change and its consequences under different planning scenarios.
A technical report provides detailed information about the Virginia Development Vulnerability Model. Included in the report are:
Spatial data with metadata are available for download in ArcGIS file geodatabase format, along with an ArcGIS map document with symbolized layers for exploring the data. The geodatabase contains the following three raster datasets, each with 30-m pixels:
To download the data, click here. High-resolution maps (PDF or PNG format) and alternative raster data formats are available on request.