Use of high-water marks and effective discharge calculation to optimize the height of bank revetments in an incised river channel

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61988987%3A17310%2F20%3AA210246W" target="_blank" >RIV/61988987:17310/20:A210246W - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0169555X20300702" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0169555X20300702</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.geomorph.2020.107098" target="_blank" >10.1016/j.geomorph.2020.107098</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Use of high-water marks and effective discharge calculation to optimize the height of bank revetments in an incised river channel

Popis výsledku v původním jazyce

In deeply incised rivers, bankfull discharge (i.e. the flow filling the channel to the top of the banks) does not represent channel forming flow and increasingly large flows are associated with increasingly large boundary shear stress. In such rivers, solid bank revetments (rip-rap, gabions, retaining wall) are usually constructed to the top of the banks—similarly as in vertically stable rivers—despite the fact that the upper parts of the banks may never be flooded. To optimize the height of solid bank revetments in deeply incised channels, it is thus important to determine whether a flood magnitude can be identified, for which the combination of flow duration and bedload transport rate results in the highest river efficiency to transport bedload and perform geomorphic work. This question was explored in the Morávka River, Czech Carpathians, which deeply incised into non-resistant flysch bedrock over the past few decades. Observations of high-water marks (e.g. trash lines, wash lines) after a flood in 2014 enabled reconstruction of the peak flood stage in the deeply incised reach and the adjacent, vertically stable reach. These observations, together with post-flood measurements of cross-sectional channel geometry, distances between consecutive cross sections and estimates of channel roughness, were used in one-dimensional hydraulic modelling aimed to determine a peak discharge of the flood in a number of cross sections in both reaches. Despite the close proximity of both reaches, markedly higher discharge values were obtained for the incised reach and the discrepancy was used to calibrate roughness coefficients for the incised reach. A flow-duration curve determined on the basis of a 25-year series of daily discharges in the upstream gauging station together with data about channel geometry and roughness in the incised cross sections were used to simulate bedload transport at successive discharges with the BAGS sediment transport model.

Název v anglickém jazyce

Use of high-water marks and effective discharge calculation to optimize the height of bank revetments in an incised river channel

Popis výsledku anglicky

In deeply incised rivers, bankfull discharge (i.e. the flow filling the channel to the top of the banks) does not represent channel forming flow and increasingly large flows are associated with increasingly large boundary shear stress. In such rivers, solid bank revetments (rip-rap, gabions, retaining wall) are usually constructed to the top of the banks—similarly as in vertically stable rivers—despite the fact that the upper parts of the banks may never be flooded. To optimize the height of solid bank revetments in deeply incised channels, it is thus important to determine whether a flood magnitude can be identified, for which the combination of flow duration and bedload transport rate results in the highest river efficiency to transport bedload and perform geomorphic work. This question was explored in the Morávka River, Czech Carpathians, which deeply incised into non-resistant flysch bedrock over the past few decades. Observations of high-water marks (e.g. trash lines, wash lines) after a flood in 2014 enabled reconstruction of the peak flood stage in the deeply incised reach and the adjacent, vertically stable reach. These observations, together with post-flood measurements of cross-sectional channel geometry, distances between consecutive cross sections and estimates of channel roughness, were used in one-dimensional hydraulic modelling aimed to determine a peak discharge of the flood in a number of cross sections in both reaches. Despite the close proximity of both reaches, markedly higher discharge values were obtained for the incised reach and the discrepancy was used to calibrate roughness coefficients for the incised reach. A flow-duration curve determined on the basis of a 25-year series of daily discharges in the upstream gauging station together with data about channel geometry and roughness in the incised cross sections were used to simulate bedload transport at successive discharges with the BAGS sediment transport model.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10508 - Physical geography

Projekt

—

Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

GEOMORPHOLOGY

ISSN

0169-555X

e-ISSN

—

Svazek periodika

356

Číslo periodika v rámci svazku

1. květen 2020

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

15

Strana od-do

1-15

Kód UT WoS článku

000527302000009

EID výsledku v databázi Scopus

2-s2.0-85079875487