지상 라이다 기반 입목의 흉고직경과 수고의 정확도 평가

초록

The measurement of standing trees for forest resource surveys in forests is generally performed by surveyors using direct measurement tools. However, in-situ measurement errors can occur often due to consistency and inaccuracy. To address this problem, LiDAR (Light Detection and Ranging) technology has recently been applied for forest resource surveys. In this study, we evaluated the applicability of terrestrial LiDAR technology for forest resource surveys in pure forests. Two stands ((1) Chamaecyparis obtusa and (2) Quercus variabilis) were selected, which are located within the academic forest of Jeonbuk National University, Jeonju-si, Republic of Korea. Diameter at breast height (DBH) and tree height (H) were measured by surveyors as a reference and those values were compared with those measured using handheld and fixed LiDAR instruments. Tesults showed that a high level of agreement was observed between the measurement methods for DBH in the C. obtusa stand, while the difference in mean values was not significant. For H, a low level of agreement was observed, and the difference in mean values was significant. Specifically, in the three-point moving average height, the handheld LiDAR instrument overestimated H by 0.3 m, while the fixed LiDAR instrument underestimated counterpart by 1.2 m. In the case of the Q. variabilis stand, there was a high level of agreement in the DBH measurements, and a relatively high level of agreement was also observed in H measurements. Furthermore, the differences in mean values for both DBH and H were not significant. These results suggest that although terrestrial LiDAR technology can provide the high accuracy in DBH measurement for both C. obtusa and Q. variabilis stands, as well as in H measurement for Q. variabilis stand, H measurement should be improved for the C. obtusa stand. This study is an initial stage of research on the application of terrestrial LiDAR technology for forest resource surveys in pure forests, and accordingly the need for further research on various tree species and environmental conditions.

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