(2) Results 
Of the results of the 15 trials with different 
number s of units in their hidden layers, networks 
with 11 units were the best ones for both degree 
and extent. The accuracies which w ere evaluated 
the ratio of points estimated within 0.25 
estimation error to supervisor, were 86.4% and 7 
9.4% . They approximately satisfied the accuracy 
necessary for evaluation. 
Figure 6 and Figure 7 are results of map 
calculation using network parameters for degree 
and extent of | and degradation. Figure 8 shows t he 
hazard ranking as a whole. It was produced by 
reclassifying outputs of the multiplication. 
  
S 
Severe — — Moderate 
Figure 6. The estimation for the degree 
of land degradation. 
(*Color Printed) 
  
3 aE SS RRR M 
5 Rank3 à 
SS Rank4 ud 
From Southeast 
    
Char acteristics related to natural factors of the 
hazar dous zones are shown in Tables 3 to 7. They 
are occupied area of different ranks in each 
category. Specific features were not clear for 
elevation, slope, direction of aspect and vegetation 
coverage, because they were distributed in 
proportion to the ratio of each category over the 
whole ar ea. On the other hand, features r elatedto 
soil category shown in Table 6 were unique. Though 
most of test sites were Calcic Xerochrept (Xero. 
deep, Xero. slop) and Litic Xerorthent (Xerot.), the 
hazardous sites were in Gypsic Xer ochr ept (Gy ps.) 
or Litic Xerochrept (Liti.) categories. Since they 
were stony soil, soil structures with stone and 
rock appear to influence land degradation. 
d 
Severe Qo Moderate 
Figure 7. The estimation for the extent 
of land degradation. 
(*Color Printed) 
    
Rank 2 
Rank 3 
#88 Rank 4 From North 
  
  
Figure 8. The hazard map for land degradation. (*Color Printed) 
792 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B7. Vienna 1996 
dM oe ja wa- 8