EAWAG news 55e (March 2003)
Alpine Waters - Fragile Diversity in Peril (Entire volume)
Editorial: Behind the Alpine Scenery
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Bernhard Wehrli
Lead Article
Sights Set on Alpine Water Treasure
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Ulrich Bundi
Water plays a determining role in the Alpine region: it represents untouched
nature, sensitive ecosystems, and a resource that can be used in many different
ways. These natural and utilitarian values are being threatened or destroyed
by one-sided and intensive use. The alpine regions are, therefore, challenged
to manage their water resources in a sustainable manner. At the same time,
it is essential that interests are coordinated across national boundaries.
Millions of people live along European rivers and depend on these alpine water
resources. In light of predicted global warming, international cooperation
is becoming ever more important.
Research Reports
Does the Convention for the Protection of
the Alps Preserve Its Water Resources?
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Mario F. Broggi, Swiss Federal Institute for Forest, Snow and Landscape
Alpine streams are in jeopardy: the space allotted to streams and rivers
is often inadequate, water quality is poor, and discharge is too low. Since
the Alps are of primary importance to Europe's water supply, it is urgent
that we take action. As early as 1991, the European Union and countries that
share parts of the Alps agreed on a Convention for the Protection of the Alps.
In order to minimize the risk to streams and rivers and to increase awareness
of the importance of our water resources, the convention will soon be extended
into a water protection protocol.
Alpine Streams: Diverse and Sensitive Ecosystems
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Mäggi Hieber, Center for Applied Ecology Schattweid
Who does not know them - babbling mountain brooks and roaring glacier streams?
They are still the quintessence of raw beauty and untouched nature; or are
they? Because of the prevailing harsh conditions and their inaccessibility,
remarkably little is known about alpine streams and their inhabitants. A comprehensive
project conducted at EAWAG has been able to show that alpine streams comprise
of a wide variety of habitats. Their resident flora and fauna have numerous
ways of adapting to the often extreme conditions, though even the smallest
disturbances by anthropogenic impacts or climate change may irrevocably destroy
these sensitive ecosystems.
Alpine Lakes: Extreme Ecosystems under the
Pressures of Global Change
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Roland Psenner, University of Innsbruck
Cold temperatures, lack of nutrients, intensive UV radiation or darkness for
months make high mountain lakes extraordinary habitats. The organisms they
harbor must be experts in adaptation; however, even these remote lakes are
no longer untouched. Anthropogenic influences add to natural factors and affect
these ecosystems. Since high mountain lakes are particularly sensitive to
environmental change, they are used as early warning systems. It remains to
be seen, however, what direction these changes will take.
Archives in the Depths of High Mountain Lakes
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Michael Sturm
Humans began settling remote mountain regions of the Swiss Alps over 4000
years ago. So what were the Alps like in earlier times? Downturns in climatic
conditions forced humans to repeatedly abandon these areas, but as soon as
conditions improved, they returned. We can decipher these fluctuations in
human settlement from the sediment record that is stored in mountain lakes.
These archives allow us to assess the effect of human impacts on the background
of natural climatic changes.
Alpine Hydroelectric Power Plants and their
"Long-range Effects" on Downstream Waters
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Alfred Wüest
Alpine hydroelectric power plants not only affect the local waters, but also
streams and lakes that lie far downstream. The transport of suspended solids,
for example, is significantly reduced below reservoirs, which affects the
oxygen content of lower lying lakes. Apart from suspended solids, reservoirs
also retain nutrients. The collapse of landlocked salmon populations in the
Canadian Columbia River, for example, appears to be caused by the construction
of several dams, which reduced the nutrient concentrations in downstream lakes.
Hydroelectric power generation also changes the temperature regime of downstream
waters.
The Third Rhone Correction: Rehabilitation
Despite Operation of a Power Plant?
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Markus Fette
In contrast to past corrections of the Rhone, the Third Correction, which
is currently in the planning stage, will return some of the space that has
been "taken" from the river. The river corridor will be widened
in a number of places, which will both improve flood protection and the river's
ecological viability. The current situation is, however, rather complex. Over
the past 50 years, several new hydroelectric power plants have been built
in the alpine headwaters of the Rhone, which cause pronounced periodic changes
in the water level of the river. EAWAG is currently investigating how the
proposed broadening of the river corridor - and continuing fluctuations in
water level - will affect groundwater levels and whether or not a natural
ecosystem will be able to become re-established under these conditions.
Effects of Global Climate Change on Alpine
Aquatic Systems
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Bruno Schädler, Bundesamt für Wasser und Geologie
Global climate change has a direct effect on the alpine aquatic cycle. The
last decade was probably the warmest period of the last 1000 years. If this
trend continues, there will be significant consequences for the water cycle
in Switzerland. Predictions are that summers will be drier, while winters
will see more precipitation. Snow lines will increase but glaciers will recede
dramatically or disappear altogether. What consequences would these changes
have for the streams and rivers in the alpine region?
In Brief
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Publications
Please feel free to submit questions or suggestions any time to the editor Martina Bauchrowitz.