Proximity functionality in GRASS?

[Greg Thacker]

Dianne,

There are several ways you can go about this.  This might be one solution.

You will need to know your map resolution.  Detrmine how many units are in
a 5 mile area.

Run the program r.buffer.

For the highway study.

First Step:
Run a mask on areas other than 3-5 degrees. GRASS comand r.mask

Second Step:
Run r.buffer and set the buffer to 50meters.

Greg Thacker
USACERL-TAS