Spatial Analysis Based on Raster Data Processing - Introducing Geographic Information Systems with ArcGIS - page 491

Exercise 8-2 (Project)

Solving the Original Wildcat Boat Problem with Rasters

The raster data model has some unique strengths. It is particularly suited to modeling the environment.
Its advantages are that each area (cell) is homogeneous and is the same size and shape. Further, each
area has four nearest neighbors and four next-nearest neighbors. As computers become more powerful—
much larger memories and much greater speeds—raster processing is becoming a tool that started with
cell sizes measured in miles to those measured in feet (and not many of those).
Raster data modeling trades geographic specificity for

❏ Speed

❏ Storage economy

❏ Simplicity

❏ Large group of tools

I want to introduce raster processing using the problem we solved in the last chapter regarding the
location of the Wildcat Boat facility. This particular problem is probably better solved with vector
processing, but solving it using raster processing techniques is very instructive.
We'll start by setting up a folder for your work and then converting the relevant geodatabase feature
classes to rasters.

1. Start ArcCatalog. Find the folder named

[___] IGIS-Arc\Spatial_Analyst_Data

Highlight it and choose Edit > Copy. Find

___ IGIS-Arc_ YourInitials

and highlight it. Choose Edit > Paste. Make a folder connection to

___ IGIS-Arc_ YourInitials

\Spatial_Analyst_Data\WC_Boat_SA.

Expand WC_Boad_SA completely to see the five feature classes that you are familiar with.

Setting the General and Raster Environment

When you are using vector feature datasets the bounding rectangle of the data pretty much takes care of
itself, once you set the coordinate system. Not so with raster data. The raster is a rectangle, and when
you combine rasters, you want them to represent the same area. So, we will set the output extent—in this
case to the extent and projection of the vector feature class Soils.

2. Start ArcMap with a Blank Map. Dismiss ArcToolbox, if it is present. Add as data

___ IGIS-Arc_ YourInitials \Spatial_Analyst_Data\