( 7 ) Area still snowcovered after June 22nd, I960 
(interpretation by Urs WÄLDER, M.A.) 
- 357 - 
snowfall, the other with large snowfalls and very late disappearance of the 
snowcover) will be taken also into consideration. 
3.2. Grevasalvas 
The following data-sets are presently at disposition and stored in the 
geographical information system (Lit. 9): 
- Agricultural land-use 
- Snowcover 
- Altitude 
situation of July 7th, 1972 
situation of August 4th, 1972 
situation of September 9th, 1972 
situation of March 17th, 1972 
situation of March 30th, 1972 
situation of May 2nd, 1972 
situation of May 23rd, 1972 
average altitude of each area unit 
The snowcover here is classified in five categories, for the land-use 
up to twenty categories were used. Fig. 4b and 5 each give an example of the 
corresponding computer output for snowcover and land-use. Besides the great 
advantage that all preparing steps for a further processing and printing and 
an easy addition of complementory information are taken, the calculation and 
tabulation of the areal extension of the various features is possible. This 
allows a qualitative and quantitative calculation and printing of ecological 
parameters. 
The snowcover (Fig. 4b) was interpreted from b&w aerial photographs of 
an approx, scale of 1 : 18'000. Ground control and measurement of snowdepth 
provided additional information. The land-use data were compiled from b&w 
photos (l : 18'000), color photos (appr. 1 : 15'000) and from oblique color 
pictures made with a Hasselblad camera. Additional data-sets are in prepa 
ration, e.g. for soils, geology, vegetation, phenology etc., which will be 
complemented by longterm ground observation and measurements of climatic 
elements, in particular of solar radiation etc.. 
4. CONCLUSIONS 
For geoecological studies in high mountain terrain and especially for 
mapping the seasonal and yearly changes of the different surface features 
various remote sensing systems are needed for the data acquisition . 
Additional information from ground observation and other sources are 
important. 
For geoecological studies not only qualitative but also quantitative 
data are essential. 
A computerized geographical information system storing the coded data in 
matrix form and therefore allowing a geographical location of each single 
information provides the best basis for a further processing and corre 
lation for geoecological applications.