1. Associate Professor, Dept. of Geography, Univ. of Calgary, Calgary, AB, Canada T2N 1N4 (corresponding author).
2. GIS Manager, Isis Geomatics, 3582 30 St. N., Lethbridge, AB, Canada T1H 6Z4.
3. Chief Executive Officer, Isis Geomatics, 3582 30 St. N., Lethbridge, AB, Canada T1H 6Z4.
4. Vice President, Isis Geomatics, 3582 30 St. N., Lethbridge, AB, Canada T1H 6Z4.