NLCD Grid Mapping and West Nile

Applications of National Landuse Classification Datasets (NLCD) to West Nile Surveillance.

The NLCD datasets provide us with valuable information related to human ecological features and how they might impact west nile ecology. NLCD maps are grid (raster) images with each cell bearing a defining color feature. These color assignments are standardized, though not at all perfected in terms of how they match the actual landuse activites as we might pricture them on our own maps of landuse. For this reason, a new series of color patterns had to be developed for application to NLCD maps, for example, to assure that all water-related features were blue, and nothing else was blue.

Once this was developed, the NLCD was put to use in inspected how trap sites are portrayed in GIS of NLCD data. The following examples depict the ecology and landuse features of one of the more ecologically-sound regions of the county. This area also underwent considerable review with regard to species diversity and density patterns, phytoecological impacts on west nile natural ecology sites, and the possible use of local plant types as indicators of species absence or presence at a site.

The first depiction represents a very sound ecological setting for mosquito ecology in general. This particular trap site demonstrated the greatest species diversity and perhaps represents one of the least impacted ecological settings for the county. The second NLCD image is of the positive testing site documented for 2002 and 2003. The productivity of this area in relation to a nearby site of high suspicion is detailed in the non-NLCD map that follows.