H/(Q*-G),
G), can be
n all cases,
d, as the
nited water
verpass, is
/ vegetated
This would
> places. In
be made:
ist patches,
be stated,
concluded,
se sites, as
model for
the energy
be made at
campaign.
d Stewart
evaporation
far as they
8 1.6
8
Schnee /bebaut
E Wasser
[Ratio CH+Eq>/CQ#-G)
i £4 06
Z
| Xnklination 4 2
uu To < TL o. H.wert
Fig. 4. Ratio (H+LE)/(Q*-G)
Tab. 2 shows the statistics of the ratio (H+LE)/(Q*-G) for
some of the land use classes:
very dry heath | dry heath | moist heath | meadow
salix
heath birch forest | moist heath birch forest
112 0,84 1,15 1,34
0,93
0,91 0,78
Tab. 2. mean values of (H+LE)/(Q*-G) for different land use classes
The statitics show together with the visual interpretation,
that the modelling results have different qualities for the
land use classes.
The dry heaths and meadows show values above 1,0.
These sites generally show dry conditions, a fact that
Causes the actual evapotranspiration rate to be lower
than the one calculated by Eq. In the case of dry heaths
I can be commented, that the land use classification
Shows a high confusion rate between moist heaths and
dry heaths in a way, that many sites that actually are
Moists heaths are classified as dry heaths. This would
explain the low coefficient for dry heaths.
For the heath birch forests, equilibrium evaporation
Seems to model best the actual evapotranpiration rate.
667
For the moist heath birch forest, this condition is no
longer true, as evapotranspiration for this moist forest
type evidently is higher than equilibrium evaporation.
This observation is supported by the authors who
investigated equilibrium evaporation in high latitude
sites.(Rouse/Stewart, 1972).
10. CONCLUSIONS
It has been shown, that sensible heat flux can be
modeled with good accuracy on mountainous slopes
under stable atmospheric conditions, using the slope
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B7. Vienna 1996
