SPOT綠度與森林生育地因子於台灣杉材積推估之探討

Evaluation on Integration of SPOT NDVI and Forest Habitat Factors for Estimating Timber Volume of Taiwania

謝漢欽(Han-Ching Hsieh)

《台灣林業科學》 13卷3期 (1998/09) Pp. 175-188

https://doi.org/10.7075/TJFS.199809.0175

摘要

本研究以東勢林區之大安溪事業區之SPOT影像常態化差異植生指數，及由數值地形資料推算之溫度指數、相對水分梯度、全天空光域、全年平均直射光空域，以及來自本區的台灣杉人工造林地之地理資訊的林齡和樹冠鬱閉度，當作自變數，材積當作應變數。以多變異統計逐步迴歸分析，配合地形組構因子的分層方法，進行台灣杉人工林材積推估模式的建立與分析。研究結果顯示，全區材積推估模式受到地形效應的影響。依地形組構因子之合理分層，減少地形變異，可提高材積推估的正確度達80%。依自變數取得的難易程度，可選定最適台灣杉材積推估模式。

關鍵字

常態化差異植生指數 ； 遙感探測 ； 森林生育地因子 ； 地理資訊系統 ； 台灣杉

並列摘要

This study focused on Taiwania plantations on forest land of the Danaen working circle in the Donshu National Forest. The normalized difference vegetation index as greenness of each stand was calculated from a SPOT image. Four forest habitat factors, temperature index, synthetic moisture gradient, whole sky space, and direct light incidence ratio, associated with topography and location were derived from digital elevation data. In addition, the Taiwania stand age, crown closure, and volume were selected from the forest land-use geographic information data base. Greenness, 4 forest habitat factors, stand age, and crown closure of the entire area of each stand were independent variables, and stand volume as was the dependent variable in the multivariable stepwise regression analysis which searched for the best volume estimate model. Through stratifying the terrain configuration factor derived by the digital terrain model, relieving the higher relief stratification from each stand stepwise, R^2 of the best model was able to reach 0.80. This shows that the Taiwania volume estimate models are affected by the variance of terrain. According to how easy it is to acquire the dependent variables, the optimal timber volume estimate models can be selected by the analysis procedure in this study.

並列關鍵字

NDVI ； remote sensing ； forest habitat factor ； geographic information system ； Taiwania