!!!Hochwasser

Flood, water level or runoff exceeding a certain limit (usually the 
lowest high-water level of a year). This limit is calculated from the 
water levels and flow rates or local topographical characteristics. In 
hydrographical statistics the term is also used for the peak value of 
a hydrographic curve.

\\
Before 1821 high-water marks of the River Danube were only 
occasionally recorded. Since then continuous records have been kept of 
the water levels of Linz, since 1828 also of Stein (Krems) and of 
Vienna. Soon after, other marks were also recorded. From 1893 
additional flow-rate values and studies of the high waters of the 
River Danube were recorded. Because of occurrences of extreme draughts 
and high waters the hydrographical central office (Hydrographisches 
Zentralbuero) was established in the Ministry for the Interior in 1893 
and the national hydrographical service in 1894. The latter is still 
responsible for the observation and recording of the hydrological 
cycle, for the observation of water levels and the high-water 
information service.

\\
The most extensive floods of the River Danube occurred in 1501, 1787, 
1899, 1954 and 1991. On the tributaries to the River Danube the 
highest water levels so far were recorded on the Rivers Enns 1572, 
Traun 1594, Salzach and Inn 1598. The area around the River Mur/Mura 
was particularly hit by extensive floods in 1938, that of the River 
Drau/Drava in 1903, 1965 and 1966. Severe floods in 1997 particularly 
affected parts of Lower Austria, as various southern tributaries of 
the Danube overflowed the levees. Floods can be caused by heavy rain 
and snow fall, by excessive thawing or by ice jams. After the 
regulation of the larger rivers at the end of the 19%%sup th/%  
century, structural alterations to the Austrian water courses carried 
out after World War II mainly served the purpose of protection 
against floods. Since the 1980s the ecological functions of a body of 
water have been paid more attention in planning alterations, so that 
more and more flood plains and retention basins have been built to 
protect against floods.

!Literature
W. Kresser, Die Hochwaesser der Donau, 1957; 
Veroeffentlichungsverzeichnis des Hydrographischen Dienstes in 
Oesterreich, 1994.


%%language
[Back to the Austrian Version|AEIOU/Hochwasser|class='wikipage austrian']
%%

[{FreezeArticle author='AEIOU' template='Lexikon_1995_englisch'}]
[{ALLOW view All}][{ALLOW comment All}][{ALLOW edit FreezeAdmin}]