P. Bolduc et al., Automated estimation of localized forest volume from large-scale aerial photographs and ancillary cartographic information in a boreal forest, INT J REMOT, 20(18), 1999, pp. 3611-3624
The development of an automated method for obtaining locally reliable estim
ates of forest volume is demonstrated for a mixed-species boreal forest of
the Lac St. Jean region of Quebec. The method relies on the ability of an a
lgorithm based on local maxima to identify individual stems from a scanned
aerial photograph under the assumption that the points of maximum light ref
lectance will be the highest points on individual trees. This information i
s linked via regression analysis to mean heights of dominant and co-dominan
t trees and ground-based forest inventory data to provide a statistical rel
ationship with forest volume. It was demonstrated that, by using the method
, the local uncertainty of volume estimates could be decreased by 61% relat
ive to standard forest inventory procedures. The method is not applicable t
o young or disturbed stands. The greatest difficulty with the method is tha
t sample plots used for validation must be locatable with absolute accuracy
on the scanned aerial photographs-something that is likely to be problemat
ic in many forest conditions.