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| human 
abili- 
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| aerial 
ions 
the 
rium 
lata show 
rosio- 
nn beca- 
ins on 
.Ons are 
yarkhan- 
changed. 
          
  
Increased plant density stabilizes the sand surface and the area 
of moving sands is diminished. In such a way barkhan dunes are 
trasformed to barkhan-hummock sands. The results of aerial photos 
interpretation show that duration this of process is IO-I5 years, 
We have also estimated that vegetation development on 
takyr surfaces leads to the change of relief forms. After the rooting 
single plants on takyr sand accumulation occurs, takyr surface is 
covered with sand layer. Large takyr areas are affected now by this 
process, That leads to the reduction of sites where some years ago 
runoff water was gathered. 
The estimated trends in reduction of eroded areas and their 
overgrowing by vegetation are mainly explained by the increasing of 
climate humidity. Human activity also plays an important role. Regu- 
lations in utilization of natural resources (limitation of grazing, 
tree cutting prohibition) have eliminated the effect of negativ 
processes, 
It is khown that interpretation of space photos be combi- 
ned with appiication of aerial photos and ground truth collection, 
Space photos contain integrated images of natural objects, they can 
be used in compilation of medium and small scale maps. Aerial photos 
study and ground truth collection provide detailed infarmation on 
terrain processes. So the combination of all these types of investi- i 
gations allow to correct existing thematic maps and prepare new maps, Hii 
especially maps of nature conservation. Hi 
The results of investigations on key areas has supported the 
idea about efficienay of remote sensing by study of vast and almost . 
inaccessible desert regions. Remote sensting methods provide the user 
with operative, regular and ofjective information by low cost. Aerial 
and space photos allow to obtain images of the same areas, that is 
very important in natural processes dynamics study. That creates the 
basis for the desert environmental monitoring at the global, regional 
and local level. 
  
  
  
  
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