Since a road layer of the appropriate spatial scale and coverage was not available for the study area, we used available information to extrapolate road frequencies for this study.First we calculated road frequencies from the DOQs using 1 ha grid cells. Then we used those sampled grid cells to calculate road frequencies for the six major owner classes (USFS, BLM, PNI, PI, State and MISC) in the study area. This resulted in the following ownership class-specific road frequencies (number of ha with roads):

Owner	No. Obs	Freq.
USFS	850	56.4%
BLM	220	55.0%
PNI	492	60.6%
PI	1094	48.0%
State	114	57.0%
Misc.	too few	N/A

We then calculated an area-weighted road frequency for each 6th Field Watershed by multiplying the ownership class-specific road frequency by the area occupied by each ownership class for each 6th field.

Extrapolated road frequencies can be used help prioritize / rank 6th Field Watersheds until more detailed roads information becomes available.

Exercise caution in using the extrapolated road frequencies. These data were generated from a very small number of observations in the MidCoast area (< 1%). This method, however, can be used to get a more representative sample.

Spreadsheet Data: extrapolated_road_freq.xls

Shapefile: extrapolated_road_freq.zip (436K)

Click To Enlarge

Avg: 49.9 % ha with road
Max: 60.6 % ha with roads
Min: 38.5 % ha with roads

Please address questions or comments to:

Dr. Ralph Garono
Principal Investigator
Earth Design Consultants, Inc.
rgarono@earthdesign.com

Laura Brophy
Principal Investigator
Green Point Consulting
brophyl@peak.org | homepage