Only the data as received from remote sensing techniques are considered 
further. For each single feature (e.g. land-use at a specific date) of a 
thematic group a data-set has to be prepared. The following major remote 
sensing systems were used in at least one of the test areas for the follo 
wing purposes: 
- Multi-sequence b&w photography 
- Multi-sequence color photography 
- Multi-sequence IR-color photography 
- Multi-sequence large-scale oblique IR 
and color photographs from small 
aircrafts 
- IR thermal scanner (two channels) 
- Orthophotography 
snowmelting process, geomorpholo- 
gy/landforms, land-use, 
agricultural land-use, vegetation, 
phenology, vegetation, soil 
moisture, 
special phonological situations 
(blossom of a specific plant and 
its distribution) etc., 
geomorphology, hydrology, glacio 
logy» snowmelt, 
data base for information grid. 
The interpretation of these different data received cannot be dis 
cussed any further; we refer to the existing literature (Lit. 6-8). 
2.2. Comparison of different data-sets 
In a second step the individual data-sets have to be compared with 
eath other to evaluate the relationships and correlations between different 
elements, which will ultimately lead to the definition of ecological para 
meters. Two methodological approaches are considered: 
- a visual or graphical comparison, 
- a quantification of data and integration into an information system. 
The first method asks for a transference of the interpreted data onto 
an equal data base (e.g. a map) where they can be compared visually and 
graphically. This technique may be used only for a limited number of data 
sets. The method is applied in the Dischma test site, where for the entire 
valley the influence of the snowmelting process on the distribution of the 
plant communities and the phenology is one of the main study objectives. The 
method will not be discussed any further, but results are presented in 
chapter 3. 
If a greater number of data-sets are available and new ones will be 
added further on, ecological comparisons may be gained only by quantifying 
and coding the data and storing them in a computerized information system. 
For the compilation of such a geographical information system based on re 
mote sensing data two main problems occur: 
- the geographical location of each single information in a coordinate system, 
- the quantification and coding of the interpreted data for storing in a 
data-bank.