GIS Programming: Working with Rasters
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Rasters are one of the two primary data models used in GIS. While vectors use points and line segments to identify locations on Earth, rasters define space using a matrix of equally sized cells. Two modules included within the ArcPy package allow access to many geoprocessing tools designed to work with raster data and imagery, which is a specific type of raster data. These modules are the Spatial Analyst ( arcpy.sa ) and Image Analyst ( arcpy.ia) modules. Our task for this week's lab was to write a script that creates an output raster layer identifying areas that fall within a given set of parameters regarding slope, aspect, and land cover class. More specifically, the output layer had to identify areas with the following characteristics: Forest land cover (classifications 41, 42, and 43) Slope between 5°and 20° Aspect between 150°and 270° Below is a flowchart which outlines the various steps of the script. One challenge I had while writing the script was trying to assign b...