MONITORING OF ENVIRONMENTAL PARAMETERS IN ALPINE REGIONS
BY MEANS OF SATELLITE REMOTE SENSING
Mathias Schardt, Heinz Gallaun, Ursula Schmitt, Klaus Granica
JOANNEUM RESEARCH, Wastiangasse 6, A-8010 Graz
e-mail: mathias.schardt@joanneum.ac.at
Thomas Häusler
GAF, Arnulfstraße 197, D-80634 München
e-mail: haeu@gaf.de
KEY WORDS: Forest Monitoring, Alpine Regions, Image Pre-Processing, Data Fusion, Image Calibration
ABSTRACT: In this document change detection methods for monitoring alpine forest areas will be demonstrated and
discussed. The parameters to be monitored by means of remote sensing methods are forest parameters such as crown
closure and forest types. The potential of satellite remote sensing for the classification of the alpine environment has
been demonstrated in many investigations. However, it has been shown that the detection of slight changes such as
decreasing canopy closure, succession stages of the forests or changes in the proportional distribution of coniferous,
broadleaf and mixed coniferous/broadleaf forest is very difficult due to insufficiencies in change detection as well as
appropriate pre-processing methods. Only if these methods are available, increasing amount of new information
resulting from the multitemporal source data sets can be optimally utilised. The introduced investigation therefore pays
special attention to the technical requirements of a monitoring system in terms of data pre-processing as well as of
different calibration procedures. The investigation is carried out in the "Dachstein Region" of the Austrian Alps. The
presented results have been conducted - amongst others - in the context of the project "Pilot Study in the Field of
Monitoring of Forested Areas" financed by DG VI and the CEO-project "Inventory of Alpine-Relevant Parameters for an
Alpine Monitoring System Using Remote Sensing Data" financed by DG XII.
1. BACKGROUND
While the Alps represent one of the most sensitive
ecosystems in Europe the pressure on them is far greater
than on other environments. This is due to an aggressive
development drive in the past, huge numbers of tourists
as well as environmental damage. Forests have recently
been subjected to particularly damaging natural as well as
anthropogenic influences. The catastrophic storms of the
last decade, the resultant, and lasting problem of the bark
beetle, and global climatic changes have weakened the
resilience of alpine forests. Far-reaching changes have
also been anticipated for agricultural land. Intensive
farming, the excessive use of fertilisers, overgrazing,
forest grazing, and grass-cutting adversely diminish the
potential of the alpine regions as agricultural patrimony.
Concurrently with this development we also find that more
and more alpine pastures are no longer being grazed or
cultivated, so that the pastures are gradually taken over
by spreading forest. A third area of concern is the use of
alpine land for tourism which increasingly is at odds with
the aims of nature and landscape preservation. On the
other hand the resultant change in the face of the
landscape typically associated with the Alps has a
negative impact on tourism, which is an important
economic factor. The culminative effect of all these factors
often proves disastrous, resulting in irreversible changes
in the composition and distribution of regional plant
communities, habitats as well as in agricultural areas. In
order to enable preventive measures the availability of
updated information on the status and development of the
alpine environment is indispensable. Satellite remote
sensing represents an appropriate instrument for
objective assessment of these changes.
2. TEST SITE
The test area covers the Dachstein region in Upper Styria,
Austria. The area is dominated by the high mountain
character, with its highest peak, the "Hoher Dachstein",
reaching 2995 m. The area lies within marginal alpine
climate with maritime influences, profuse precipitation and
low limits. The characteristic plant society of the mountain
range is marginal alpine beech-fir-forest, where the
frequency of beeches diminishes with altitude and
beeches and firs are replaced by spruce. In the sub-
alpine shrub-range mountain pines are dominant. The
alpine range and higher areas are covered by more or
less closed alpine grassy heathlands on detritus soils as
well as pioneer vegetation.
The ecosystem has recently come under major stress
both as a result of natural disasters and of anthropogenic
influences. Recent damage to the forests, the disastrous
storms of 1990 and the subsequent bark beetle attacks as
well as global climatic changes have reduced the
resistance of the trees, and as a result, also the protective
capabilities of the forests (protection against erosion,
overly rapid water drainage and subsequent risks of
flooding and debris flows, and against avalanches).
Actual and better information on the condition of alpine
vegetation is therefore needed.
266 International Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 7, Budapest, 1998
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