earticle

영어

The objectives of this study were to extract the major variables of forest structure characteristics such as the shape of the crown and the location of the individual trees by using Unmanned Aerial Vehicle(UAV) and evaluate the accuracy by comparing the extracted information with field data conducted in the Pinus koraiensis plot(Plot 1) in Wonju-si, and Larix leptolepis plot(Plot 2) in Hongcheon-gun, Gangwon-do. UAV images were classified into forest gap areas by using Otsu’s and Entropy methods. Moreover, the crown of an individual tree was delineated by applying Watershed(WS) and Valley Following(VF) algorithms. The estimated crown variables were compared with the field data and the accuracy was analyzed. Additionally, the point showing the highest reflectance value in the crown was considered as the location of each tree by using the local maxima filter. In the Plot 1, the overall accuracy and Khat of crown overlap ratio were 0.80 and 0.59, respectively, when using the Entropy_WS method, which were the highest values. The positional error was 0.74m in X-coordinate and 0.62m in Y-coordinate, which were within 1m of high accuracy. In the Plot 2, the overall accuracy and Khat of crown overlap ratio were 0.78 and 0.51, respectively, when using the Entropy_VF method, which were the highest. The positional error RMSE was 0.59m in X-coordinate and 0.38m in Y-coordinate, which were the highest among all.