670 
Wanne 
    
        
   
Vegetation cartography by 
vegetation - remote sensing at 1:200,000 and 
flora and vegetation 
stalionel inventory 
Ground plotting 
  
  
  
Image Processing G.I.S Flora data 
base 
  
  
  
  
  
  
Fig. N 1: General organization chart of the adopted 
methodology. 
3. PRESENTATION OF THE ZONE OF AIN RICH. 
We delimited a geographical zone of about 
146,107.8 ha, comprised between the latitudes 34? 52' 
38.23" and 35?10'17.56" North and the longitudes 3?52' and 
4°17 East (Figure N°2). 
  
  
  
  
Figure N° 2: NDVI of the North ALGERIA from NOAA / 
AVHRR data 
Zone of study AIN RICH is represented by a square. This figure 
corresponds to a NDVI image of the third decade of May 1990. The 
reddish hues correspond to a strong chlorophyllian activity. The 
green hues concern a medium activity, whereas the sallow hues 
represent a weak chlorophyllian activity. 
The zone of survey is managed by the Daira of Djebel 
Messaád and is situated in the heart of the steppe, commonly 
named « steppe Sud Algéroise». This zone is characterized 
«schématically» by the existence of a thermal gradient and a 
rain fall relatively important, by the presence of chalky 
substratum and by the existence of a variable landscape from 
steppes to forests. 
3.1.Geology and lithology 
The Southern part of the territory of study is 
constituted of alignments of the topography oriented North 
East _ South West, essentially composed by cretaceous 
géologic terrain , to a dominance of sandstone-like and 
chalky. But then the alignments of the Northern mountains 
are characterized by a marlaceous tendency . Between these 
two alignments morpho-structural, one finds some steppics 
plains formed of little thick sets of quaternary age 
3.2.Géomorphology 
The ground cover in the region of Djebel Messaad, 
as for the whole of Algerian steppic territory, is greatly 
bound to the geomorphology. Two important physiographic 
shapes disengages geologic in link with the structure and to 
the nature of the rocks which constitutes the geologic 
substratum. 
3.2.1. The Mountains, hills and summit 
These sets which constitute the Atlas Sahara essentially come 
from the evolution of a topography creases trained by the 
spatial succession more or less regular of conve narrow 
bulge (anticline) and of concave hollow (syncline) rather 
large. The altitude of these reliefs is included between 918 m 
(Oued El Onk) and 1676 m (Djebel Fernane). These shapes 
of topography are occupied bv a forest vegetation (in the 
Fernane Mountain, Ouzina, Tsegna, Boudenzir, Grouze etc.). 
3.2 2. The more and less flat surfaces 
These surfaces correspond to the glacis, that they are of 
accumulation or of denudation surrounding the mountains. 
This shape of relief results from several conditions of 
geneses as the stiff slope of some Mountain, the evacuation 
of the rubbles on the glacis and the absence of a linear very 
marked erosion. However, several shapes of glacis which fit 
together theones and the other could be distinguished: 
1. the high glacis which dates of midle quaternary 
2. the glacis of adjusting of midle quaternary (more recent) 
joining the reliefs with the high glacis. They present 
some chalky accumulations under shape of incrustation. 
3. the glacis of recent quaternary: are constituted by alluvial 
deposits and such colluvium like terraces of ouady. The 
chalky accumulation, less important, is presented in the 
from of nodules and sometimes of incrustation. 
3.3.The vegetation 
The vegetation which composes the site is represented by: 
I. The forests groupings (dense and lucid forests) which 1s 
present on nearly half of covering plant and translates the 
wealth of the « daira of Djebel Messaad » in forests 
species; 
2. the groupings of sub-forests (raised matorrals); 
3. the steppe degraded of Stipa Tenacissima, with 
Artemisia Herba Alba and Noaea Mucronata. 
4. THE RESULTS 
The map obtained by processing presented in the 
methodological approach adopted (chapter IL) gives the 
distribution of the units of ground cover in the studied zone. 
The supervised classification used is the maximum of 
likelihood (see figure 3 and 4 ) allowed to classify the 
Intemational Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 7, Budapest, 1998 
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