Data from an Indian satellite has provided scientists of the
TU Berlin with evidence of growing damage to forests in Saxony.
The high- resolution images are being used to determine the exact
degree of damage, and will provide documentation for later comparisons.
Indian satellite images are now providing evidence of the harmful
effects suffered by the forests of Saxony as a result of out-dated
industrial practice in the north of the Czech Republic. After
the German unification, the forests showed signs of improvement,
but as production began in the factories along the border sulphur
dioxide pollution again increased markedly, and large areas of
forest have again died. But this is only one of the findings of
a research project on which researchers at the Technische Universität
(TU) Berlin are currently working. Other project objectives relate
to reforestation measures.
In cooperation with the Forestry Agency of Saxony, researchers
at the TU Institute of Landscape Development are evaluating high-resolution
satellite data. The results can be presented at a scale of 1 :
10 000. This quality now makes it possible to localise forest
damage more precisely and to recognize individual tree species
or types of forest. Of special interest are the affected tree
species in the "Erzgebirge" and the Dübener Heide
in Saxony. In addition to the Forestry Agency of Saxony, this
pilot project is also supported by the German Centre for Aeronautics
and Astronautics (DLR).
"At first we wanted to evaluate the data from the MOMS-2P
satellite, but following the series of mishaps on the Russian
MIR space station we had to rethink. We are now using the Indian
satellite system IRS-1C", explained project leader Prof.
Hartmut Kenneweg. This has high resolution sensors with good sensitivity
throughout the spectrum and it provides images on which objects
can be identified with at six metres square. "By comparing
and combining various data sets we can obtain detailed images
on the computer" explains team-member Bodo Coenradie. This
means, for example, that firebreaks, tracks or forest clearings
can be visualised particularly well.
The interpretation of the individual pixels is now automated.
However, the scientists have had to define the processes beforehand,
and regular cross-checking is necessary. Recognising damage to
the forests still requires a trained eye. Standard evaluation
is possible on the basis of the code of practice of the VDI (Verein
Deutscher Ingenieure) which Hartmut Kenneweg helped to formulate.
It specifies how images from the bird's eye-view should be interpreted,
and shows the crowns of different types of tree with various degrees
Such an aerial inventory offers important advantages over an evaluation
of forests from the ground. Firstly, it is hoped that the use
of high-resolution satellite data could save time and money. But
it is also possible to carry out measurements of large areas on
the computer to high levels of precision. And the overall evaluation
of damage to the forest can often be carried out better than a
forester on the ground is able to achieve. "They have particular
difficulty registering gradual changes on their daily rounds through
their forest", is how Hartmut Kenneweg sums it up. In addition
to the inventory of damage to the forests, it is now planned to
set up an archive which will be available for comparisons with
This method has been used in this case to draw up forestry maps
for Saxony, but other applications are also possible. It could
be used, for example, to monitor agricultural land, and perhaps
detect fraudulent claims for EU subsidies. Survey data would also
be very useful as the basis for evaluations if areas of state-owned
forest are to be privatised. Only recently the effects of the
storm "Lothar" demonstrated how important it can be
to have accurate data. Not only does it allow an assessment of
the damage caused, but it is also an invaluable aid to the foresters
who have to decide on reforestation measures. The great-grandchildren
of the owners will be able to manage a healthy stand of forest,
thanks to the assistance provided to the planners by these satellite
Contact: Prof. Hartmut Kenneweg, Technische Universität
Berlin, Institute of Landscape Development
Special field: Landscape planning and management,
Research project: "Improved forest monitoring
with MOMS-Priroda data"
Address: Str. des 17 Juni 135, 10623 Berlin, Germany,
Tel.: +49 30 314-73491, Fax: +49 30 314-23507, Internet: www.tu-berlin.de/fb7/ile/fg_natur/forsch/forsch.htm
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