Morphological changes and riffle-pool dynamics related to flow in a meandering river channel based on a 5-year monitoring period using close-range remote sensing

Tutkimustuotos: Lehtiartikkelivertaisarvioitu

Standard

Morphological changes and riffle-pool dynamics related to flow in a meandering river channel based on a 5-year monitoring period using close-range remote sensing. / Salmela, Jouni ; Kasvi, Elina; Vaaja, Matti Tapio; Kaartinen, Harri; Kukko, Antero; Jaakkola, Anttoni; Alho, Petteri.

julkaisussa: Geomorphology, Vuosikerta 352, 106982, 01.03.2020.

Tutkimustuotos: Lehtiartikkelivertaisarvioitu

Harvard

APA

Vancouver

Author

Bibtex - Lataa

@article{d0b145d96f7d4d89ba467fdf6750029f,
title = "Morphological changes and riffle-pool dynamics related to flow in a meandering river channel based on a 5-year monitoring period using close-range remote sensing",
abstract = "The maintenance of riffle-pool sequences and morphological changes in the long-term have received little attention in the literature. The aims of this study are to determine morphological changes and riffle-pool maintenance in relation to flow conditions in a meandering river channel over a 5-yr period. Change detection was focused on riffle and pool maintenance in a river reach covering three successive meander bends. Changes in a meandering river channel were studied utilizing detailed digital terrain models and flow data. The results indicated that riffle-pool sequences are maintained by high discharge events and the development of pools and riffles was linked. During high discharges, the riverbed eroded on the concave sides and the inflexion points aggraded, causing riffle–pool sequences, whereas during low discharges, concave sides aggraded and inflexion points eroded, causing pool filling and riffle erosion. While discharge increased, near-bed flow velocities increased faster on the concave sides of the bends than at the inflexion points, becoming higher at a discharge of 8 m3/s, ~20{\%} of the bankfull discharge. Changes in the three successive meander bends were mainly similar, and the geometry of meandering rivers contributed to the locations of riffles and pools. Pools and riffles were not stable in size and shape, but their longitudinal location remained the same, instead of migrating up and down the channel. Morphological changes occurred in meander bends year-round, but they were non-linear. Annual channel change was not similar from year to year owing to different flow regimes and morphological changes during the previous year. However, seasonal detection revealed similarities between high and low discharge periods between the years. Concave sides of meander bends may act to temporarily store sediment; however, storage is preserved only under the effective hydrological discharge.",
keywords = "Change detection, Riffle-pool, Digital terrain model, Flow measurements",
author = "Jouni Salmela and Elina Kasvi and Vaaja, {Matti Tapio} and Harri Kaartinen and Antero Kukko and Anttoni Jaakkola and Petteri Alho",
year = "2020",
month = "3",
day = "1",
doi = "10.1016/j.geomorph.2019.106982",
language = "English",
volume = "352",
journal = "Geomorphology",
issn = "0169-555X",

}

RIS - Lataa

TY - JOUR

T1 - Morphological changes and riffle-pool dynamics related to flow in a meandering river channel based on a 5-year monitoring period using close-range remote sensing

AU - Salmela, Jouni

AU - Kasvi, Elina

AU - Vaaja, Matti Tapio

AU - Kaartinen, Harri

AU - Kukko, Antero

AU - Jaakkola, Anttoni

AU - Alho, Petteri

PY - 2020/3/1

Y1 - 2020/3/1

N2 - The maintenance of riffle-pool sequences and morphological changes in the long-term have received little attention in the literature. The aims of this study are to determine morphological changes and riffle-pool maintenance in relation to flow conditions in a meandering river channel over a 5-yr period. Change detection was focused on riffle and pool maintenance in a river reach covering three successive meander bends. Changes in a meandering river channel were studied utilizing detailed digital terrain models and flow data. The results indicated that riffle-pool sequences are maintained by high discharge events and the development of pools and riffles was linked. During high discharges, the riverbed eroded on the concave sides and the inflexion points aggraded, causing riffle–pool sequences, whereas during low discharges, concave sides aggraded and inflexion points eroded, causing pool filling and riffle erosion. While discharge increased, near-bed flow velocities increased faster on the concave sides of the bends than at the inflexion points, becoming higher at a discharge of 8 m3/s, ~20% of the bankfull discharge. Changes in the three successive meander bends were mainly similar, and the geometry of meandering rivers contributed to the locations of riffles and pools. Pools and riffles were not stable in size and shape, but their longitudinal location remained the same, instead of migrating up and down the channel. Morphological changes occurred in meander bends year-round, but they were non-linear. Annual channel change was not similar from year to year owing to different flow regimes and morphological changes during the previous year. However, seasonal detection revealed similarities between high and low discharge periods between the years. Concave sides of meander bends may act to temporarily store sediment; however, storage is preserved only under the effective hydrological discharge.

AB - The maintenance of riffle-pool sequences and morphological changes in the long-term have received little attention in the literature. The aims of this study are to determine morphological changes and riffle-pool maintenance in relation to flow conditions in a meandering river channel over a 5-yr period. Change detection was focused on riffle and pool maintenance in a river reach covering three successive meander bends. Changes in a meandering river channel were studied utilizing detailed digital terrain models and flow data. The results indicated that riffle-pool sequences are maintained by high discharge events and the development of pools and riffles was linked. During high discharges, the riverbed eroded on the concave sides and the inflexion points aggraded, causing riffle–pool sequences, whereas during low discharges, concave sides aggraded and inflexion points eroded, causing pool filling and riffle erosion. While discharge increased, near-bed flow velocities increased faster on the concave sides of the bends than at the inflexion points, becoming higher at a discharge of 8 m3/s, ~20% of the bankfull discharge. Changes in the three successive meander bends were mainly similar, and the geometry of meandering rivers contributed to the locations of riffles and pools. Pools and riffles were not stable in size and shape, but their longitudinal location remained the same, instead of migrating up and down the channel. Morphological changes occurred in meander bends year-round, but they were non-linear. Annual channel change was not similar from year to year owing to different flow regimes and morphological changes during the previous year. However, seasonal detection revealed similarities between high and low discharge periods between the years. Concave sides of meander bends may act to temporarily store sediment; however, storage is preserved only under the effective hydrological discharge.

KW - Change detection

KW - Riffle-pool

KW - Digital terrain model

KW - Flow measurements

UR - http://www.scopus.com/inward/record.url?scp=85076760956&partnerID=8YFLogxK

U2 - 10.1016/j.geomorph.2019.106982

DO - 10.1016/j.geomorph.2019.106982

M3 - Article

VL - 352

JO - Geomorphology

JF - Geomorphology

SN - 0169-555X

M1 - 106982

ER -

ID: 39157323