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Morphological changes on meander point bars associated with flow structure at different discharges

Auteur(s) et Affiliation(s)

KASVI, E.
Dept. of Geography and Geology, Univ., Turku, Finlande
VAAJA, M.
Aalto Univ., School of Science and Technology, Dept. of Surveying, Espoo, Finlande
ALHO, P.
Dept. of Geography and Geology, Univ., Turku, Finlande
Aalto Univ., School of Science and Technology, Dept. of Surveying, Espoo, Finlande
HYYPPÄ, H.
Aalto Univ., School of Science and Technology, Dept. of Surveying, Espoo, Finlande
Metropolia Univ. of Applied Science, Civil Engineering and Building Services, Helsinki, Finlande
KAARTINEN, H.
Finnish Geodetic Inst., Dept. of Remote Sensing and Photogrammetry, Masala, Finlande
KUKKO, A.
Finnish Geodetic Inst., Dept. of Remote Sensing and Photogrammetry, Masala, Finlande


Description :
This study investigates the impact of flow structure of different discharges on meander point bar morphology. The study reach is located in northern Finland on the meandering, unregulated Pulmanki River in the valley of Pulmanki. The AA. carried out mobile and terrestrial laser scanning campaigns before and after a flood on 2 sandy-bed point bars. Between the scans, the flow structure was examined using an Acoustic Doppler Current Profiler at 3 flow stages. The results indicated that a meander point bar both affects and in turn, is itself modified by the flow at different discharges. The lower flow stages also have a significant effect on point bar morphology, especially on deposition over the bar head. Secondary circulation is responsible for scroll bar formation on the point bar margin beyond the apex. Finally, the shape of the bend and the grain size distribution control the impacts of the flow structure, leading to divergent morphologies of point bars with certain generic features.


Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2013, vol. 38, n°. 6, p. 577-590, nombre de pages : 14, Références bibliographiques : 2 p.

Date :
2013

Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley

Langue :
Anglais
Droits :
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