Barbosa, Paulo 
Burned area in 1991 
Mobilization in 1993 
  
Figure 2. Landsat TM RGB image (bands 5, 4, 7) showing forest burned area in 1991 and mobilization in 1993. 
Comparison with the post-fire mobilization map of 1991-1993. 
The validation of the maps was done using the 1995 ortho-rectified aerial photographs on a number of test areas. Two 
types of test areas were chosen: areas that suffered terrain mobilisation and areas that didn’t suffer terrain mobilisation. 
Since the ortho-photos were from 1995, and the period under analysis spanned from 1991 to 1995, it was necessary to 
use them together with the support of the RGB Landsat images, in order to define the test areas. 
The results of the validation are given in the form of a confusion matrix (Table 2), from which a number of indicators 
were derived (Table 3): users and producers accuracy, omission and commission errors, overall accuracy, and Kappa 
(Congalton, 1991). : 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
Mobilisation Map 
Mobilisation No Mobilisation TOTAL 
Ortho-photos Mobilisation 1881 664 2545 
ond dsati Tig No Mobilisation | 149 13217 13366 
TOTAL 2030 13881 15911 
Table 2. Confusion matrix showing the number of pixels used for the validation of the change detection process. 
INDICATORS Mobilisation No Mobilisation 
Producers Accuracy: 74% 99% 
Users Accuracy 93% 95% 
Omission Error 26% 1% 
Commission Error 7% 5% 
Overall Accuracy 95% 
Kappa 79% 
  
  
  
  
Table 3. Indicators of the change detection quality. 
  
130 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000. 
Amb mb mà mud 
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