Stream channel changes as a result of sudden sediment release due to check dam lowering (Polish Carpathians)

Autor: Anna Lenar-Matyas, Joanna Korpak
Rok vydání: 2019
Předmět:
Zdroj: Environmental Earth Sciences. 78
ISSN: 1866-6299
1866-6280
DOI: 10.1007/s12665-019-8396-8
Popis: Channel response to dam removal is still poorly understood, as there is a lack of monitoring data. A small dam in the gravel bed Krzczonowka Stream was lowered in 2014 as the first in the Polish Carpathians. The paper describes the direction and magnitude of channel changes after the check dam lowering against the backdrop of slow changes in the riverbed occurring over a period of several decades. Geomorphologic mapping and geodetic measurements started in 2013 and were repeated in 2014. Archived cartographic sources were used to identify channel morphology in the past. After the studied check dam had been partially lowered, a flood occurred and caused movement of sediment from the reservoir into the channel downstream. Debris filled pools and artificial riffles were created in 2013—the largest deposition occurred just below the dam. The channel width also increased in this area. The channel reach upstream from the dam was incised. Additional gravel supply is limited because of a sequence of drop structures just upstream of the studied reach. Long-term channel evolution after dam lowering depends on flood events and the availability of material for fluvial transport.
Databáze: OpenAIRE
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