On Friday, June 30 at 10 a.m. Tobias Gutzmann will present his MSc Thesis “Estimation of Above-ground Biomass of Trees in Würzburg using Object-based Interpretation of Airborne Imagery”
From the abstract:
With increasing recognition of the importance of urban forests, remote sensing provides tools
to accurately measure vegetation on an individual tree level. Urban trees function as an
important carbon storage in a city, but their behavior is different from their natural forest
counterparts. While the role of trees in a global scale is widely known, the impact on a regional
scale is less well documented. Three image segmentation algorithms are applied on a high-
resolution orthophoto to evaluate their ability to delineate tree crowns correctly. Then,
improvements on the segmentations are attempted through merging algorithms. Tree genus
classification was carried out with additional spectral and textural features to evaluate whether
they improve classification. The resulting tree crowns will be used to estimate different tree
parameters and their current carbon storage.
I find that none of the segmentations could achieve the desired tree crown delineation initially.
Through merging, the result from eCognition Multiresolution Segmentation performed much
better. Additional image features improved tree segment and tree genus classification and
regression is a feasible approach for tree parameter estimation if no height data is available.
Lastly, this study found a total of 929.753 trees for Würzburg storing approximately 287.002 t
carbon.
1st supervisor MSc:
Dr. Michael Thiel
2nd supervisor MSc:
Dr. Sarah Schönbrodt-Stitt
