航空機LiDARによる森林資源量推定―密度の異なるスギ・ヒノキの林分パラメータ推定―

抄録

The purpose of this study was to assess the potential for estimating important parameters of forest stands with small footprint LiDAR (Light Detection and Ranging) data. The study area was a plantation of Sugi (Cryptomeria japonicaD. Don) and Hinoki (Chamaecyparis obtusa Endl.) with plots of differing densities. We explored the relationships between field survey data and LiDAR data using scatter plots and regression analysis. The targeted parameters were stem number, mean tree height, mean DBH (diameter at breast height) and mean stem volume. DBH was indirectly obtained from the tree crown surface area, and the timber volume was indirectly obtained from DBH. We confirmed that the coefficients of determination were 0.80-0.94 and there was a high correlation in stand parameters, except for Hinoki mean tree height. However, the relative error of Hinoki mean tree height was only 0.22m. Hinoki relative error of DBH and timber volume was greater than that of Sugi. We assume that this was due to a decrease in accuracy of DTM (Digital Terrain Model), as the Last-pulse did not reach the ground because of interference by Hinoki tree crown structure. In addition, it is possible that there are inaccuracies in the tree crown surface area data due to other reasons.