Introducing Geographic Information Systems with ArcGIS: A Workbook Approach to Learning GIS, 3rd Edition

Reclassifying the Data

When we solved the Wildcat Boat problem with vector-based GIS, we combined landuse, soils, the sewer buffer, and the stream buffer. After some manipulation we will now do the same with the rasters. We have

Landuse_rr2m

Soils_rr2m

Sewer_buf_rr2m

Stream_buf_rr2m

The strategy will be to reclassify the values of each of these rasters. We’ll make the value “one” if the zone meets the requirement, and zero or NODATA otherwise.

For Landuse_rr2m, this means changing all the values to “0,” except for landuse type code “300,” which we change to “1.”

For Soils_rr2m, we will change values of “0” and “1” (both of which indicate unsuitability) to “0.” We will change the values “2” and “3” to “1.”

For Sewer_buf_rr2m, we will replace the numbers of meters within which building is allowed (300) with “1,” leaving NODATA alone.

For Stream_buf_rr2m, the matter is a bit different. The values of 20 we want to replace with NODATA, while we give the current NODATA values a “1.”

Once we have done this, we merely add the four rasters together, so that the sum at each location is a 0, 1, 2, 3, or 4. From the way we constructed the reclassification, a cell must have a 4 in it to be eligible to be a part of the areas that would allow the Wildcat Boat facility.

____ 31. Using Search, find and run the Reclassify (Spatial Analyst) tool. For the Input raster, browse to Landuse_rr2m in Wildcat_Boat_SA.mdb (or select it from the drop-down menu, which is easier). Set the Reclass ...