입목수간재적표 기반의 입목재적 추정의 불확실성과 이에 따른 탄소축적 추정의 편향: 강원도 홍천군을 대상으로 (Uncertainty in Estimating Forest Growing Stock from Volume Estimation of a Standing Tree by Stem Volume Table and the Resulting Bias in Carbon Stock Estimation: A Case Study in Hongcheon-Gun, Republic)

서지정보

· 발행기관 : 한국기후변화학회
· 수록지 정보 : 한국기후변화학회지 / 13권 / 3호 / 355 ~ 364페이지
· 저자명 : 신중훈, 한희, 김영환, 임종수, 장윤성

초록

The purpose of this study was to quantify the uncertainty in the estimation of forest growing stock and carbon stock that occurs as DBH (Diameter at Breast Height) and HT (Height) are rounded when locating stem volumes in a stem volume table, and to present a case study using the Hongcheon-gun NFI (National Forest Inventory) data. We quantified the uncertainty of the estimated value of the stem volume obtained from the stem volume table, assuming that the stem volume calculated by the stem taper equation is the true value, and the resulting bias in carbon stock estimation, using two indicators. In all the indices, as DBH and HT increased, a trend was observed in which the absolute values of these indicators increased. BIAS appeared as a positive value in all sections, which means that the stem volume table with rounding DBH and HT underestimated stem volumes. BIAS was found to range from 0.0134m3 to 0.0178m3 depending on the species. RMSE (Root Mean Square Error) was about 4 ~ 7 times greater than BIAS with the same tree sizes. The increase rate of stem volume was almost constant regardless of HT, but increased as DBH increased. This indicates that DBH is more effective in reducing rounding-induced uncertainty when using stem volume tables. Note that rounding DBH combined with this characteristic led to systematic underestimation of stem volume. As a result of estimating the growing stock in the forests of Hongcheon-gun, Gangwon-do using the stem taper equation and the stem volume table, it was confirmed that the stem volume table underestimated the growing stock by 1,475,606m3, and accordingly, did the carbon stock by 860,232 tC.
Even if the figure was limited to Hongcheon-gun, it was difficult to consider it a small value. As projects related to greenhouse gas reduction are expected to become more active in the future compared to the past, uncertainty in such estimates may affect the reliability of such projects.
Therefore, it is necessary to provide a tool that can calculate stem volume and carbon stock by directly inputting DBH or HT values.

영어초록

The purpose of this study was to quantify the uncertainty in the estimation of forest growing stock and carbon stock that occurs as DBH (Diameter at Breast Height) and HT (Height) are rounded when locating stem volumes in a stem volume table, and to present a case study using the Hongcheon-gun NFI (National Forest Inventory) data. We quantified the uncertainty of the estimated value of the stem volume obtained from the stem volume table, assuming that the stem volume calculated by the stem taper equation is the true value, and the resulting bias in carbon stock estimation, using two indicators. In all the indices, as DBH and HT increased, a trend was observed in which the absolute values of these indicators increased. BIAS appeared as a positive value in all sections, which means that the stem volume table with rounding DBH and HT underestimated stem volumes. BIAS was found to range from 0.0134m3 to 0.0178m3 depending on the species. RMSE (Root Mean Square Error) was about 4 ~ 7 times greater than BIAS with the same tree sizes. The increase rate of stem volume was almost constant regardless of HT, but increased as DBH increased. This indicates that DBH is more effective in reducing rounding-induced uncertainty when using stem volume tables. Note that rounding DBH combined with this characteristic led to systematic underestimation of stem volume. As a result of estimating the growing stock in the forests of Hongcheon-gun, Gangwon-do using the stem taper equation and the stem volume table, it was confirmed that the stem volume table underestimated the growing stock by 1,475,606m3, and accordingly, did the carbon stock by 860,232 tC.
Even if the figure was limited to Hongcheon-gun, it was difficult to consider it a small value. As projects related to greenhouse gas reduction are expected to become more active in the future compared to the past, uncertainty in such estimates may affect the reliability of such projects.
Therefore, it is necessary to provide a tool that can calculate stem volume and carbon stock by directly inputting DBH or HT values.

참고자료

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