Tree Crown Mapping in Managed Woodlands (Parklands) of Semi-Arid West Africa Using WorldView-2 Imagery and Geographic Object Based Image Analysis
Artikel i vetenskaplig tidskrift, 2014

Detailed information on tree cover structure is critical for research and monitoring programs targeting African woodlands, including agroforestry parklands. High spatial resolution satellite imagery represents a potentially effective alternative to field-based surveys, but requires the development of accurate methods to automate information extraction. This study presents a method for tree crown mapping based on Geographic Object Based Image Analysis (GEOBIA) that use spectral and geometric information to detect and delineate individual tree crowns and crown clusters. The method was implemented on a WorldView-2 image acquired over the parklands of Saponé, Burkina Faso, and rigorously evaluated against field reference data. The overall detection rate was 85.4% for individual tree crowns and crown clusters, with lower accuracies in areas with high tree density and dense understory vegetation. The overall delineation error (expressed as the difference between area of delineated object and crown area measured in the field) was 45.6% for individual tree crowns and 61.5% for crown clusters. Delineation accuracies were higher for medium (35–100 m2) and large (􏱇100 m2) trees compared to small (<35 m2) trees. The results indicate potential of GEOBIA and WorldView-2 imagery for tree crown mapping in parkland landscapes and similar woodland areas.

parkland

tree crown mapping

tree crown delineation

high spatial resolution

Burkina Faso

remote sensing

woodland

agroforestry

WorldView-2

geographic object based image analysis

Författare

Martin Karlson

Linkopings universitet

Heather Reese

Sveriges lantbruksuniversitet

Madelene Ostwald

Chalmers, Energi och miljö, Fysisk resursteori

Göteborgs universitet

Sensors

1424-8220 (ISSN) 1424-3210 (eISSN)

Vol. 14 22643-22669

Ämneskategorier

Geovetenskap och miljövetenskap

DOI

10.3390/s141222643