Detection of pine stands damaged by pine wilt disease using IKONOS data. Jpn. 」. For . Plann. 40 : 203 -210,2006 This study used IKONOS " Geo " imagery to detect damage to pine stands caused by pine wilt dis・ ease , The study was conducted in pine stands on Mt . Tsukuba in Ibaraki Prefecture , Japan. 66 plots ( / 0m × 10m each ) were established in the study area , taking damage ratjo into considera − tion ; all the trees were tallied and examined f r damage . Ratios of damage , healthy pine

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... es , and hardwood trees were then calculated in terms of basal area 、 Pan − sharpened colour imagery and multi − spectral imagery were analysed , and normalised difference vegetation index ( NDVI ) values were calculated fronl the images , The relationshjp between the mean NDVI for pixels in the plots and the field . observed conditions in the plots was then examined . The damage ratio and the ra − tio o 「 hardwood trees tended to decrease and the ratio of healthy pine trees tended to increase as the NDVI increased for the two imagery types. Moreover , to validate a prediction method , regression equations were derived from half of the plots and applied to the other half of the plots . The root mean square errors ( RMSEs )of predicting the damage ratio and ratio of healthy pine trees from the NDVI were approximate [ y O, 15 and O. 12, respectively , for the pan −sharpened imagery ;the RMSEs for the same two ratios were approximately Oユ7 for the multi ・ spectral jm . age 「 y . *