Table 3 Discrimination table of the damage of the check points 
by Landsat TM data and the aerial photographs 
  
Discrimination by aerial 
photographs 
  
  
  
  
  
  
  
  
  
No. of 
check 
Heavy | Slight No points 
damage| damage | damage 
Discrimination | Heavy 30 7 3 i 
damage | (75.0) | (17.5) (7.5) 
by Landsat 
TM dar Slight 14 22 5 
a damage| (341) | (537) | (122) ai 
  
  
Table 4 Damged area for each municipality surveyed by Hida 
Local Development Office 
  
  
  
  
  
  
  
  
  
  
  
  
  
Damaged areas estimated b 
Damaged area 8 y 
Municipali surveyed by Local Landsat TM data (ha) 
unicipality D 
evelopment 
Office (ha) Heavy damage | Slight damage Total 
Hida city 2851 1584 5379 6962 
Ohyama town 636 24T 663 910 
Amagase town 1510 192 1593 2385 
Maetsue village 1361 579 1449 2028 
Nakatsue village 665 458 1186 1644 
Kamitsue village 1825 478 1403 1881 
  
  
points were discriminated as the slight heavy;and 14 points 
as the heavy and 5 points as no damage by the aerial photo- 
graphs. Most (7596) ofthe points discriminated as the heavy 
damage by Landsat TM data were the heavy damage, but 
the points discriminated as the slight damage by Landsat 
TM data include not a little (34.196) the heavy damage. 
Putting together the heavy and slight damage,the damaged 
areas can be discriminated with an accuracy of about 90% 
by Landsat TM data. Examinating 8 points discriminated 
as no damage by the aerial photographs,4 points were red 
pines and 3 points were deciduous trees and 1 point was 
a cutover. Their spectral reflectance characteristics may be 
similar to those of the damaged areas. 
tural Office,controls over 6 municiparities shown in Fig. 
6.EVALUATION OF THE Dam. 
AGED AREAS EXTRACTED By 
LANDSAT TM DATA 
6.1 Evaluation using the aerial pho. 
tographs 
À part of the area covered by the aerial 
photographs was extracted from the out- 
put image of the damaged areas, and its 
magnified image was generated. 8] 
points extracted as the heavy and slight 
damages were selected as check points 
for the evaluation in the magnified im- 
age. 40 points were selected as the heavy 
damage and 41 points as the slight. The 
state of damages for the check points 
were carefully examined using the aerial 
photographs and Table 3 is a discrimi- 
nation table of damages for the check 
points discriminated by Landsat TM data 
and the aerial photographs. Among 40 
points discriminated as the heavy dam- 
age by Landsat TM data,30 points were 
discriminated as the heavy damage,and 
7 points as the slight and 3 points as no 
damage by the aerial photographs. The 
numeral in parentheis shows percentage. 
Among 41 points discriminated as the 
slight damage by Landsat TM data,22 
6.2 Evaluation using data on the damage surveyed 
by the Local Development Office 
Hida Local Development Office,a branch of Ohita Prefec- 
| 
and surveyed damages of forests in the municiparities by 
using the aerial photographs or investigations on the ground. 
Damaged area for each municipality was surveyed by tle 
Local Development Office and was used for the evalua 
tion. Damaged area of each municipality was computed 
from the output image which extracted the damaged areas 
by Landsat TM data. Table 4 shows the damaged areas for 
514 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B7. Vienna 1996