of 
  
hical 
are 
The 
usly- 
| and 
usly- 
even 
d in 
ppies 
Its, a 
ound 
cles, 
1 the 
spots 
ning 
error 
(ated 
nd a 
> the 
arger 
  
    
  
  
  
  
  
  
Moderately- 
Areas without 
deterioration 
  
deteriorated areas 
  
Spot G (seriously-deteriorated areas) 
  
  
Fig-5 Sites of a ground survey and examples of photographs 
than a threshold vale was removed from the 
investigation point. The location of each investigation 
point and the example of photographs are shown in the 
Fig-5. Using the geometrically corrected an aerial 
photograph and GPS, correspondence between the 
aerial photograph and the ground survey spots can be 
easily established. 
From these results, it 1s confirmed that most of dead 
tree was a beech. And there was no cases that the trees 
which fell leaves in fall and winter were mis- 
  
  
   
interpreted as dead trees. Thus it is verified that the 
results of the aerial photograph interpretation are well 
consistent with the results of the ground survey. 
5. THE RELATIONSHIP BETWEEN FOREST 
DETERIORATION AND TOPOGRAPHICAL 
CONDITIONS 
The deterioration distribution is displayed as bird's eye 
view images to ease the visual analysis of the 
relationship between deterioration distribution and 
topography (Fig-6). From this, it is found that 
Seriously- 
deteriorated areas 
Moderately- 
deteriorated areas 
: Fig-6 Bird's eye view images of the results of aerial 
photograph's interpretation 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 7, Budapest, 1998 715