LARGE AREA OPERATIONAL EXPERIMENT FOR FOREST DAMAGE MONITORING IN EUROPE USING
SATELLITE REMOTE SENSING - RESULTS OF THE TECHNICAL WORKING GROUP
Mathias Schardt JOANNEUM RESEARCH, Graz
Thomas Häusler, GAF Munich
Hartmut Kenneweg, TU Berlin
Herbert Sagischewski, TU Berlin
KEY WORDS:
Forest Damage, Monitoring, Standardisation, GIS, Landsat/TM, Aerial Photo Interpretation
ABSTRACT: In January 1992, UNEP called the first Advisory Board meeting in Prague to launch the "Large Area
Operational Experiment for Forest Damage Monitoring in Europe Using Satellite Remote Sensing" (LAOE). The
Czech Republic, Poland and Germany agreed to participate by providing their relevant ongoing research projects as
contributions to the experiment. The Czech Republic was nominated to be the lead country, and UNEP offered to
provide co-ordination and secretarial services. The Advisory Board of the project appointed a Technical Working Group
(TWG), with scientists from the Czech Republic, Poland, Finland and Germany to develop a methodology and prepare
guidelines for the harmonisation of the various classification approaches for regional applications. The results and the
recommendations of the TWG will be introduced in this paper.
1. INTRODUCTION
In the 1970's, a widespread deterioration in forest health
was observed, first for the European fir and,
subsequently, also for many other tree species. Now a
large proportion of the forests in Europe is affected by
forest decline to varying degrees. Intense research on
the causes of this decline has been performed from that
time on with the result that the decline can not be
attributed to one single causal factor but rather is thought
to be the result of a multitude of adverse environmental
conditions (Hildebrandt, 1992; Skelly and Innes, 1994).
Besides the fundamental research work a great variety of
damage assessment methods have been developed, and
numerous inventories have been carried out. In order to
obtain reliable and comparable results on national and
international level it has become necessary to monitor
the forest damage by applying standardised inventory
methods.
Based on the Convention on Long Range-Transboundary
Air Pollution of 1979, the "International Co-operative
Programme on Assessment and Monitoring of Air
Pollution Effects on Forests" (ICP-Forest) was
established in 1985 by the Executive Body of the
Convention. The work is based upon national monitoring
inputs using terrestrial damage evaluation methods on
sample points. The European governments are provided
with statistics on forest condition on annual basis. This
programme was funded by UNEP during 1985-1990.
Since 1991, the countries finance the inventories
themselves.
Besides the statistics obtained through this national and
transnational surveys, more detailed data is often
required locally. Especially, there is a lack of spatial
information of the damage distribution within the
European Countries. The mapping of forest condition,
displaying the spatial distribution of damage at national
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and regional level, would be useful for determining the
causes of forest decline and in improving the visualisation
of damage statistics.
Mapping of forest condition by the means of satellite
remote sensing is a technology that should be
considered as an additional tool for the ongoing work
under the Convention. In various studies satellite remote
sensing has been shown to improve the quality of forest
change monitoring, and especially its reporting. Today
the methodology is ready for large scale operational
experiments, but not fully tested for regional damage
monitoring.
2. BACKGROUND
The necessity to perform forest damage inventories
arose with the occurrence of the first forest decline
symptoms in large areas. The individual countries,
participating in the LAOE, started from the beginning with
research work and the establishment of damage
assessment methods. These traditional methods are
based on terrestrial sample surveys and partly
accompanied by the interpretation of aerial photography.
The approaches of the inventories, the area coverage
and most of all the definition of damage classes varies
widely among the countries. Despite of the immense
costs and the lacks in providing maps, the biggest deficit
is the inability to compare the results of these different
damage assessments.
The analysis of the literature shows that satellite remote
sensing has been applied successfully in various forest
decline mapping studies. Affected trees are characterised
most conspicuously by discoloration and foliage loss,
accompanied by leaf pigment, morphological and water
content changes. It is generally acknowledged that these
factors influence the spectral reflectance and that this
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996
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