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Date Permissions Signed


Date of Award

Winter 2021

Document Type

Masters Thesis

Department or Program Affiliation

Huxley College of the Environment

Degree Name

Master of Science (MS)


Environmental Sciences

First Advisor

Wallin, David O.

Second Advisor

Helfield, James J.

Third Advisor

Maudlin, Michael

Fourth Advisor

Bunn, Andrew Godard


This paper addresses two applications of lidar remote sensing: an area-based watershed-scale analysis of forest structure used to prioritize riparian restoration projects for salmon, and an individual-tree-based analysis for tree species classification. Salmon conservation is extremely important in the Pacific Northwest, but restoration efforts have been hampered by insufficient data on riparian stand conditions. I used lidar to map riparian stand structure and composition along the Nooksack River, Washington, and developed a restoration priority model based on six factors: riparian stand conditions, shade potential, cause of riparian impairment, susceptibility to climate change, position in the watershed, and proximity to intact riparian forest. Nine reaches (out of 268 total) were identified as priority targets for riparian restoration. Four of these reaches were on the upper South Fork, two were in the lower South Fork, two were in the lower Middle Fork, and one was in the North Fork near Maple Falls.

At the individual tree level, I compared six different approaches using five different algorithms to sort a discrete-return lidar point cloud into segments representing individual trees. Using these segments, I built models to predict height, diameter, conifer/deciduous classification, and species. Using the best segmentation model, I was able to classify black cottonwood (Populus trichocarpa), Douglas fir (Pseudotsuga menziesii), and red alder (Alnus rubra) with user’s accuracies up to 89%, overall accuracies of 83-92%, and kappa values above 0.6. This was the first landscape-scale study attempting to classify tree species in natural landscapes in the Pacific Northwest.




lidar, Nooksack River, riparian, salmon, tree species


Western Washington University

OCLC Number


Subject – LCSH

Salmon stock management--Washington (State)--Nooksack River Watershed; Riparian restoration--Washington (State)--Nooksack River Watershed; Optical radar--Washington (State)--Nooksack River Watershed

Geographic Coverage

Nooksack River Watershed (Wash.)--Environmental conditions




masters theses




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