تهيه جدول حجم هوايي با به كارگيري تفسير چشمي تصاوير هوايي

Preparation of Aerial Volume Table using Visual Interpretation of Digital Aerial Images

Stand volume is an important criterion in forest science for monitoring the status and function of forests, estimating forest yield and changes; and studying the effect of biotic and abiotic factors on forests. However, measurement of this forest attribute is expensive. One way for decreasing the associated costs is using RS data as aerial volume tables. In this research, UltraCamD images were used for estimating forest volume by the means of aerial volume tables. For this aim, 150 ground sample plots by 300x400 grid interval were measured. On the images, crown coverage and mean crown diameter for three nearest trees to the center of sample plots were also measured. Different combination and transformation of these two variables were then tested by stepwise regression to find out the proper variable for modeling. For determining the statistical model, linear and nonlinear regressions were used and 30 samples were leaved for model validation. The best fitted model was then linear regression and for linear model relative RMSE and bias were 22.6 and 2.9, respectively. Finally, the aerial volume table was presented.