Porres, Maru 
  
the alternate series of marl and limestone than with the areas in which only limestone is found. 
  
  
  
  
  
  
  
  
  
  
  
  
  
NDVI mean evolution * iimestones 
0,45 m maris and 
0,4 4 . limestones 
e 0354 = 1 == Lineal (limestones) 
5 0,3 ! 9 -—— -— 
$0251 £&- a € Lineal (mars and 
z 02 a limestones) 
a 
a 0,15 
0,1 
0,05 + y =0.0054x + 0.2185 
0 T : : R? - 0,2808 
0 5 10 15 20 y=0,0123x + 0,1795 
n° years R? = 0,5693 
Fig. 2 
It is due to this that the control of the solar radiation over the vegetation tends to grow, with the passing of years after 
the fire. The fig.2 shows the tendency lines over the negative correlation, in fact, if the correlation indices presented in 
table xx are analyzed, it can be observed that in all cases there has been improvement between 1987 and 1994. On the 
other hand, it deserves to be emphasized that the correlation values are larger in those areas in which we find marl with 
limestone interspersed as opposed to those which are composed only of limestone. The values of those two are more 
significant than those of sections of Keuper (formed by clay, marl and gypsum), and the worst correlation being found 
in the calcareous materials. 
That said, that the slight adjustment of the regression line can be observed over all the lithologies, due as much to the 
NDVI values as to the level of correlation with the potential solar radiation, is profoundly marked by local factors. 
The studies of detail - using area and field photographs - demonstrate that the places in which the solar radiation does 
not show an elevated significance are often associated with (i) the ground in a determined region that maintains the 
greatest predictable humidity for lithological changes neither reflected in the geological cartography of the zone, nor by 
the underground water surges and filtrations that accumulate a proportion of water in the ground greater than predicted, 
or (ii) the fire affecting the area in an disproportionate manner (Pardo, ef al., 2000). 
  
1 limestone 
n° years vs. correlation index 
® maris and limestone 
  
  
0 T T 7 3 à  Keuper 
-0,1 A 5 910 15 20 
02 Lineal (limestone) 
TU, à | 
03 4 "e * »  w| ineal (marls and 
TV, al * “a À limestone) 
= = = = Lineal (Keuper) 
  
"v 
ndi au an 
  
* 
u a 
m 
correlation index 
5 © 
4A 
  
  
  
y 7 -0,0117x - 0,1714 
-0,6 a R? = 0,233 
A 
-0,7 a y * -0.0043x - 0,447 
08 R? 2 0,0183 
c y = -0,0155x - 0,212 
n° of years R? = 0.1551 
Fig. 3 
5. DISCUSSION AND CONCLUSIONS 
Of the results presented that, without a doubt, call for the most attention are, on one hand, the modest significance that 
the hydrological parameters show when considering the recovery of vegetation and, on the other, the high significance 
that is shown by the potential solar radiation in this same matter. There are many studies that demonstrate the 
importance of the different curvature parameters, and the specific valley has concentrated an accumulation of water, 
especially those associated with underground flows (Florinsky, 1998, Moore ef al., 1991, Franklin, 1995). In the 
Florinsky and Kuryakova study (1996) in the mountainous region of Rudni Altai (East Kahazstan) correlation values 
were quite high (between -0.28 and -0.60) between the three curvature parameters studied here and the distribution of 
vegetation. It also reached significant correlations between the CA parameter and the vegetation cover. What could be 
the reason for the weak level of significance in our case? One possible explanation could come from the particular 
conditions of the ground in the area studied. The thickness in all of the cases is very small - it rarely reaches 10cm, and 
in many cases, in sunny areas above all, remains reduced to the superficial humiferous layer- so that the underground 
flows in these slopes will have little significance and the storage of water will always be scarce. The rains themselves 
  
1176 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000.