International Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 5. Hakodate 1998 
Analysis of Flood Flow by Stereomaching Method 
TAGUCHI Toshiaki, TSURU Kosuke 
Air & Space Photogrammetry Office, Aero Asahi Co. 
350-1165, Saitama, Kawagoe, Minamidai 3-1-1, 
Commission V, Working Group IC V/III 
KEY WORDS: Cameron effect, stereomatching, river bed forms, velocity vectors, HDTV 
ABSTRACT 
Former analysis of flood flow is observation of relief that is caused Cameron effect in river by operator. But it is able to 
obtain velocity vectors on the water surface automatically by using stereomatching method. Analysis of flood flow by 
stereo matching method can get more delicate change of velocity vectors than former analysis. And, it is able to obtain 
various kinds of analytical value (divergence, rotation, etc.) by calculation. So, using analysis of flood flow is possible to 
realize riverbed forms. 
It is interesting to use HDTV's image in place of aerial photographs. Because time interval of video imagery is shorter 
than aerial photographs, change of imagery caused by time interval is smaller. Then, analysis results by video imagery 
are may be more exact than analysis results by aerial photographs. 
1. ANALYZING USING AERIAL PHOTOGRAPHS 
1.1 Purpose of Analysis of flood flow 
If we can measure velocity direction of flow, water level, 
rate of discharge flow, etc, we can get available base data 
for flood control. Once we used stereo plotter to analyze 
flood flow. We got velocity vectors to plot change of 
floating matter and bubbles on aerial photographs. And 
we plotted velocity contour caused Cameron effect. 
Kinosita developed these analysis of flood flow method 
using aerial photographs in 1960's. 
We could get new knowledge about meander and 
structure of turbulent flow in flood time. Kinosita based 
this method to probed about sandbar on river bed, big 
vortex occurred in river edge, phenomenon concerning 
drift of earth and sand, etc. And he has to contributed to 
river technology field, for example planning on river 
channel. 
But, this method has some problems. 
(1) Measurement data is decided by operator to use 
stereo plotter. 
(2) 
Direction of photographing base must be parallel to 
   
the direction of flow in river to measure velocity using 
Cameron effects. 
(3) Flight course is restricted from problem (2), and 
operation of flying machine is dangerous. 
(4) To analyze flood flow in camber or meander, which 
radius curvature is small, is too difficult. 
Utami, Ueno developed to get velocity vectors without 
these problems by stereomaching method. 
1.2 Cameron Effect 
If exposure interval is enough short and there are many 
floating matter and bubbles, we can observe velocity 
distribution as 3D relief on river surface. This 
phenomenon is called as Cameron effect. 
2. ANALYSIS BY STEREOMACHING METHOD 
2.1 Stereomaching 
Analysis of aerial photograph images by stereomaching 
method has been developed since end of 1950's to 
  
    
  
    
   
    
  
    
    
   
   
    
   
  
     
   
    
   
     
   
  
  
  
  
  
  
    
     
     
   
   
   
    
   
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