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

Making a Raster Showing Straight-Line Distances to a Single Place

In the following steps, you will see how ArcMap Spatial Analyst makes a raster of Euclidean (straight-line) distances from each cell to a single “source” cell.

____ 1. Start a new blank map. From Customize > Extensions make sure the Spatial Analyst box is checked.

____ 2. Click the Add Data button. In the Add Data dialog box, navigate to the shapefile Square_grid.shp (it’s in

___IGIS-Arc_YourInitials\Spatial_Analyst_Data\Proximity_Data_SA)

and add it to the map. Make the lines of the shapefile bright red. Save the map as Proximity_startup.mxd, in

___IGIS-Arc_YourInitials\Spatial_Analyst_Data\Proximity_Data_SA

Note that “Square_Grid” appears as a 10 by 10 matrix of transparent squares. Each square is 10 units (say the units are kilometers) on a side, so the square represents a space 100 square kilometers. Square_Grid will serve as a backdrop for the next several raster datasets. You will work in your folder Spatial_Analyst_Data\Proximity_Data_SA and with the file geodatabase Prox-Exp.gdb (named for Proximity Experiments).

____ 3. Bring up the ArcCatalog tree. Navigate to

___IGIS-Arc_YourInitials\Spatial_Analyst_Data\Proximity_Data_SA\Prox-Exp.gdb

file geodatabase, and drag the raster named Onecell onto the map. Onecell is a raster consisting entirely of No Data values, except for a single cell with a value of 999. Use Identify to verify this. Open, examine, and close the attribute table for Onecell. In ...