Orre- 
bout 
EM 
data 
gital 
lage) 
  
  
/ flow O 
. watershed à river 
® 
# / Cross 
a section to 
ita . iver 
en. ^ 
Fig.4 Relationship between topographic feature 
and parameters 
is used by background of main frame. Simula- 
tion results and other vector image display on 
raster background for realization of situation. 
Digital map data ,50m mesh (altitude), is used 
by calculation of parameters for planning the soil 
saving dams. The use of digital map data is one 
  
  
| 
| 
altitude of | 
digital map data | 
| 
  
of the most unique procedure. Other vector 
data,for example,dangerous areas for 
avalanche,dangerous areas for landslide areas and 
reserve areas for wild animals were used to evalu- 
ate circumstance of soil saving dams. 
4.2 Algorithm and system flowchart 
Figure 2 shows the main frame of the system. 
Simulation results and other conditions display 
on the frame. Background of the right side in 
frame is 25000 raster image mentioned above. 
Upper part of the left side in the frame shows 
display condition of thematic maps. Lower side 
shows the areas of investigation. Figure 2 dis- 
play some vector data on the 25000 raster im- 
age. Polygon in the mountainous district shows 
watershed which was calculated from the digital 
elevation map data (50m mesh) by using the an- 
other GIS software. 
The parameters of the first dam was gave at 
control point for planning. The second dam , 
however , and other facilities were calculated au- 
  
    
w, most steep 
gradient 
  
  
    
top hight from level 
surface (Z0+h) 
  
a 
| 15m X:c3 T 
| bottom hight 
bottom width from level 
b surface (20) 
  
d 
159 X 4 x 
Fig.5 Relationship between cross-section of soil saving dam and each data point of elevation 
Intemational Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 7, Budapest, 1998 
611