Object-based Image Analysis for the Delineation of Canopy Gaps and Individual Tree Crowns using Multi-source Data: A Case Study in Haliburton Forest, Ontario

This thesis assessed object-based image analysis techniques using multi-source remote sensing data in order to automatically delineate canopy gaps and individual tree crowns (ITCs). Image segmentation is much more complex when conducted on data covering deciduous, un-even aged forests like those in...

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Bibliographic Details
Main Author: Saliola, Assunta
Other Authors: He, Yuhong
Language:en_ca
Published: 2014
Subjects:
GIS
Online Access:http://hdl.handle.net/1807/65603
Description
Summary:This thesis assessed object-based image analysis techniques using multi-source remote sensing data in order to automatically delineate canopy gaps and individual tree crowns (ITCs). Image segmentation is much more complex when conducted on data covering deciduous, un-even aged forests like those in Central Ontario. To delineate canopy gaps high spatial resolution multispectral ADS40 aerial imagery and a LiDAR CHM were assessed both separately and jointly. To delineate ITCs two commonly used segmentation approaches were assessed – region growing and watershed segmentation. Ground based measurements and manually delineated data were used as reference to evaluate results. Using multi-source data to delineate canopy gaps produced an average overall accuracy of 99.35%, whereas using the imagery and CHM individually resulted in average overall accuracies of 81.41% and 82.45%, respectively. For the delineation of ITCs, the watershed and region growing segmentations resulted in average overall accuracies of 67.5% and 65.5%, respectively.