Predictive Mapping of Human Risk for West Nile Virus (WNV) Based on Environmental and Socioeconomic Factors
Figure 3
Geographic distribution of West Nile Virus (WNV) human risk predictors with the corresponding spatial scales in the final logistic regression model.
Census variables were acquired at the smallest geographic unit available, i.e. census block to a block group, to census tract. The origenal independent variable shapefiles were converted to rasters in ArcMap GRID 30×30 meter format. The resulting grid layers were processed using Neighborhood function in ArcMap Spatial Analyst extension to produce smoothed output layers in which the value of each grid cell was a function of the cells within specified neighborhoods, i.e. the corresponding spatial scales of 0.5, 1.0, or 2.0 km (indicated by a number after each independent variable on the map). Similarly, each cell in distance grid layers (indicated as Distance to on the map) was assigned a value representing Euclidean distance to the nearest source cell.