Nauka Przyroda Technologie

2007 volume 1 issue 2 #31

Bogusław Przedwojski, Michał Wierzbicki, Joanna Wicher-Dysarz, Natalia Walczak

Emergency of flood upstream of the Jeziorsko reservoir

Summary. In the paper the assessment of the Warta river capacity is presented. The Warta river reach above the Jeziorsko Reservoir was under investigation. On the basis of field measurements the changes of capacity caused by sediment accumulation and vegetation growth were determined. The analyses presented were elaborated for the period 1991-2006. The St. Venant equations were used to assess the capacity of the Warta river channel. The model applied describes unsteady one-dimensional flow in open channels, artificial as well as natural. The computations were done for the river reach from river gauge station Sieradz (km 520+850) to the Jeziorsko Dam tailwater (km 483+300). The flood wave observed in July and August 1997 was reconstructed in the computational model. The roughness coefficients were identified and verified for the current stage of the river channel on the basis of measurements done on April 5th, 2006. The river total discharge on the measurements day was WWQ = 185 m³/s. The computations showed significant decrease of the river channel capacity in the reservoir backwater reach. The water levels in 2006 for the flows in the range from 250 to 400 m³/s increased about 0.65-0.93 m in relation to the hydraulic conditions in 1985.

Key words: flood, vegetation, reservoir sedimentation, unsteady flow modeling

Full text available in Polish in Adobe Acrobat format:
https://www.npt.up-poznan.net/pub/art_1_31.pdf

Streszczenie w języku polskim:
https://www.npt.up-poznan.net/tom1/zeszyt2/streszczenie-31.html

Corresponding address:
Bogusław Przedwojski
Bogusław Przedwojski
Katedra Budownictwa Wodnego
Akademia Rolnicza im. Augusta Cieszkowskiego w Poznaniu
ul. Wojska Polskiego 73A
60-625 Poznań, Poland
e-mail: bkpi@au.poznan.pl

Accepted for print: 10.05.2007