Weir

Example of a strike weir on the Main in Würzburg , built from 1644

A weir is a parallel or approximately parallel to the flow direction of a river arranged hydraulic engineering overflow threshold ( weir ), the operation of the drain ( overflow ) from possibly incoming excess quantities in a relief flume or reservoirs used.

A strike weir starts as soon as the water level in the channel exceeds the weir level. With this excess height, its excess rises sharply, so that the water level of the main river after the weir is pretty much limited by its height. The prerequisite for this - depending on the width and flow speed of the main river - is a sufficient length of the weir edge, also that it is not blocked by alluvial tree trunks or ice and that the weir underwater is sufficiently absorbent.

This water level limitation of the main river limits its flow and thus makes it more even. The discharge over the weir fluctuates more strongly than the incoming main river and can also dry up completely.

A weir can also be arranged laterally at curved points of a channel section. On the outside of the curve, it seems more sensitive, but is more easily laid by flotsam.

literature

Ralph Schröder, Ulrich Zanke: Technical hydraulics: Compendium for hydraulic engineering. 2nd Edition. Springer-Verlag, Berlin 2003, ISBN 3-540-00060-7 .
Heinz Patt (Hrsg.): Flood manual - effects and protection. Springer-Verlag, Heidelberg 2001, ISBN 978-3-540-67737-6 .

Individual evidence

↑ Winfried Schenk, Rüdiger Glaser , Moritz Nestle: Würzburg's environment in the transformation from the pre-industrial era to the service society. In: Ulrich Wagner (Hrsg.): History of the city of Würzburg. 4 volumes, Volume I-III / 2 (I: From the beginnings to the outbreak of the Peasant War. 2001, ISBN 3-8062-1465-4 ; II: From the Peasant War 1525 to the transition to the Kingdom of Bavaria 1814. 2004, ISBN 3 -8062-1477-8 ; III / 1–2: From the transition to Bavaria to the 21st century. 2007, ISBN 978-3-8062-1478-9 ), Theiss, Stuttgart 2001–2007, Volume III (2007), Pp. 351-368 and 1295 f., Here: p. 363.

[1] Winfried Schenk, Rüdiger Glaser , Moritz Nestle: Würzburg's environment in the transformation from the pre-industrial era to the service society. In: Ulrich Wagner (Hrsg.): History of the city of Würzburg. 4 volumes, Volume I-III / 2 (I: From the beginnings to the outbreak of the Peasant War. 2001, ISBN 3-8062-1465-4 ; II: From the Peasant War 1525 to the transition to the Kingdom of Bavaria 1814. 2004, ISBN 3 -8062-1477-8 ; III / 1–2: From the transition to Bavaria to the 21st century. 2007, ISBN 978-3-8062-1478-9 ), Theiss, Stuttgart 2001–2007, Volume III (2007), Pp. 351-368 and 1295 f., Here: p. 363.