geo- 
p ,el- 
ingle 
y us- 
ified 
)gra- 
> and 
ation 
aphi- 
rlaid 
map 
aps , 
men- 
| dis- 
pan. 
ts of 
t the 
ireas 
IVers 
)yrre- 
) ex- 
map. 
ease 
por- 
ictor 
e ac- 
1atic 
with 
that 
dan- 
ving 
need 
and 
: soil 
low. 
Many soil saving dam has been constructed in 
mountainous areas. If we want to get a detail 
contour map for plan to contract soil saving dams 
in mountainous areas, it will takes long time and 
hard works. 
We used digital map data (elevation data of 
50m mesh ) to calculate parameters for planning 
the soil saving dams. 
3. INVESTIGATION AREAS 
THURUOGI in Hokuriku district of Japan is our 
pilot area for investigation. In the areas most of 
landslide and debris flow occur near the stream 
in the valley. Many soil saving dams were already 
constructed in the areas. The contraction of min- 
istry and local government have plans for con- 
structing new soil saving dams in the dangerous 
valley. The area of the pilot site is about 400 km?. 
Figurel shows the Ishikawa prefecture where we 
mainly conducted researches. The rectangular 
" B REAL: [VERA] LE ELA sb E 
    
    
omatsy 
Fig.1 Ishikawa prefecture in Hokuriku district 
and investigation areas for pilot system 
(shaded square is about 20km long by 20km wide) 
  
  
  
  
  
  
  
  
  
  
  
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Q HE 
Q Págs 
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Q n 
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Fig.2 Main frame of pilot system 
Intemational Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 7, Budapest, 1998 
609