GEODYNAMICAL HAZARDS ASSOCIATED WITH LARGE DAMS

4.regularisation of rivers, lakes and ports to the benefit of
navigation
5. long ranged dikes against floodings and to win land
surface (Netherlands)
6. smaller and larger dams, especially in our century to
provide mechanical and electric energy.
Artificial created water surface actually on Earth, shows up
to more than 450.000 km2. About 60 larger dams exceed a
surface of 1 000 km2 each more or less 12% of the
world-wide watered surface on continents is controlled by
artificial lakes.
Two outstanding problems raised by these hydrological
technics are those of climatic influences on environment, the
second one concerns the risks engaged by the geophysical
impact of the water mass on the regional stability of geology,
especially in the neighbourhood of inhabited valleys.
If a government points out the necessity of constructing a
dam for one or several reasons, the scientific specialists and
engineers are immediately advised to study the local
hydrology, topography, geology, the environmental as well
as the economical impact, the safety control system for the
region, finally to study the rescue action in case of natural
and technological disaster.
During the last century the system of dam-construction has
changed considerably; the large heavy walls have been
replaced if possible by thin arched constructions due to the
system of pouring amorphous concrete into preconceived
iron framework. Evidently mathematical knowledge became
more and more complicated by this new, elegant method of
performing dams, but the architectural and estetic shape of
those technical buildings has reached a high level.
Encyclopaedias mention numerous large dams over the
continents of the XXth century, some covering 2000, 5000
even 8000 km2. The surface of the Gr. Duchy of Luxemburg
has only 2500 km2. Nevertheless our country succeeded to
built 2 dams and one superior lake: in Esch s/Sure and - as a
German Luxembourg co-operation - in Rosport/Vianden.
Both installations serve the population partly as drink water
reservoir, partly as hydro-electric energy source. In our
country we are extremely satisfied to note a strong attraction
on tourists.