MAPPING BAMBOO FOREST EXPANSION IN THE SUBURB OF FUKUOKA CITYUSING ASTER DATA

摘要

Wild bamboo forests have been expanded into Satoyama coppice forests, mainlyrnin western part of Japan. The uncontrolled expansion of bamboo forests is concerned of itsrnimpact to ecology in Satoyama coppice forests and increased a risk of landslide. In order tornprevent the uncontrolled expansion, it is not sufficient to investigate a present distribution ofrnbamboo forests. The past distribution and future potential distribution are essential. This paperrndemonstrated image classifications to extract the present and past distribution of bamboo forestsrnusing ASTER and LANDSAT TM data respectively. The results showed that a Decision TreernClassifier, whose thresholds were determined using ASTER band3 (near infrared) and band4rn(short wavelength infrared), could estimate the forests at the accuracy of over 70%, providedrnthat the bamboo forest area is over 4,500 square meters. It was possible to estimate thernexpansion between present and past at the accuracy of over 60%. Ultimately, a prediction maprnof bamboo forest expansion was successfully generated based on the land conditions desirablernfor the expansion.