Sharp bends associated with deep scours in a tropical river: The river Mahakam (East Kalimantan, Indonesia)
Autogenic scouring in sharp river bends has received ample attention in laboratory and modeling studies. These studies have significantly advanced our understanding of how flow processes are influenced by strong curvature and how they affect the bathymetry. Here we present a 300 km reach of the Maha...
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ftunivwagenin:oai:library.wur.nl:wurpubs/485092 2024-02-04T10:02:02+01:00 Sharp bends associated with deep scours in a tropical river: The river Mahakam (East Kalimantan, Indonesia) Vermeulen, B. Hoitink, A.J.F. van Berkum, S.W. Hidayat, H. 2014 application/pdf https://research.wur.nl/en/publications/sharp-bends-associated-with-deep-scours-in-a-tropical-river-the-r https://doi.org/10.1002/2013JF002923 en eng https://edepot.wur.nl/332156 https://research.wur.nl/en/publications/sharp-bends-associated-with-deep-scours-in-a-tropical-river-the-r doi:10.1002/2013JF002923 info:eu-repo/semantics/restrictedAccess Wageningen University & Research Journal of Geophysical Research: Earth Surface 119 (2014) 7 ISSN: 2169-9003 channel bends circular meander pools concave-bank discharge division evolution flow separation hole mackenzie delta width info:eu-repo/semantics/article Article/Letter to editor info:eu-repo/semantics/publishedVersion 2014 ftunivwagenin https://doi.org/10.1002/2013JF002923 2024-01-10T23:19:59Z Autogenic scouring in sharp river bends has received ample attention in laboratory and modeling studies. These studies have significantly advanced our understanding of how flow processes are influenced by strong curvature and how they affect the bathymetry. Here we present a 300 km reach of the Mahakam River in Indonesia, which features several sharp bends (W/R > 0.5), providing a unique field data set to validate existing knowledge on sharp bends. Scour depths were found to strongly exceed what can be expected based on existing understanding of sharp bends and are highly correlated with curvature. A comprehensive stream reconnaissance was carried out to compare the occurrence of sharp bends and deep scours with lateral bank migration. Histograms of the occurrence of erosive, stable, advancing, and bar-type banks as a function of curvature quantify the switch from a mildly curved bend regime to a sharp bend regime. In mild bends, outer banks erode and inner banks advance. In sharp bends the erosion pattern inverts. Outer banks stabilize or advance, while inner banks erode. In sharply curved river bends, bars occur near the outer banks that become less erosive for higher curvatures. Inner banks become more erosive for higher curvatures but nevertheless accommodate the larger portion of exposed bars. No relation was found between the land cover adjacent to the river and the occurrence of sharp bends. Soil processes may play a crucial role in the formation of sharp bends, which is inferred from iron and manganese concretions observed in the riverbanks, indicating ferric horizons and early stages of the formation of plinthic horizons. Historical topographic maps show the planform activity of the river is low, which may relate to the scour holes slowing down planimetric development. Article in Journal/Newspaper Mackenzie Delta Wageningen UR (University & Research Centre): Digital Library Mackenzie Delta ENVELOPE(-136.672,-136.672,68.833,68.833) Journal of Geophysical Research: Earth Surface 119 7 1441 1454 |
institution |
Open Polar |
collection |
Wageningen UR (University & Research Centre): Digital Library |
op_collection_id |
ftunivwagenin |
language |
English |
topic |
channel bends circular meander pools concave-bank discharge division evolution flow separation hole mackenzie delta width |
spellingShingle |
channel bends circular meander pools concave-bank discharge division evolution flow separation hole mackenzie delta width Vermeulen, B. Hoitink, A.J.F. van Berkum, S.W. Hidayat, H. Sharp bends associated with deep scours in a tropical river: The river Mahakam (East Kalimantan, Indonesia) |
topic_facet |
channel bends circular meander pools concave-bank discharge division evolution flow separation hole mackenzie delta width |
description |
Autogenic scouring in sharp river bends has received ample attention in laboratory and modeling studies. These studies have significantly advanced our understanding of how flow processes are influenced by strong curvature and how they affect the bathymetry. Here we present a 300 km reach of the Mahakam River in Indonesia, which features several sharp bends (W/R > 0.5), providing a unique field data set to validate existing knowledge on sharp bends. Scour depths were found to strongly exceed what can be expected based on existing understanding of sharp bends and are highly correlated with curvature. A comprehensive stream reconnaissance was carried out to compare the occurrence of sharp bends and deep scours with lateral bank migration. Histograms of the occurrence of erosive, stable, advancing, and bar-type banks as a function of curvature quantify the switch from a mildly curved bend regime to a sharp bend regime. In mild bends, outer banks erode and inner banks advance. In sharp bends the erosion pattern inverts. Outer banks stabilize or advance, while inner banks erode. In sharply curved river bends, bars occur near the outer banks that become less erosive for higher curvatures. Inner banks become more erosive for higher curvatures but nevertheless accommodate the larger portion of exposed bars. No relation was found between the land cover adjacent to the river and the occurrence of sharp bends. Soil processes may play a crucial role in the formation of sharp bends, which is inferred from iron and manganese concretions observed in the riverbanks, indicating ferric horizons and early stages of the formation of plinthic horizons. Historical topographic maps show the planform activity of the river is low, which may relate to the scour holes slowing down planimetric development. |
format |
Article in Journal/Newspaper |
author |
Vermeulen, B. Hoitink, A.J.F. van Berkum, S.W. Hidayat, H. |
author_facet |
Vermeulen, B. Hoitink, A.J.F. van Berkum, S.W. Hidayat, H. |
author_sort |
Vermeulen, B. |
title |
Sharp bends associated with deep scours in a tropical river: The river Mahakam (East Kalimantan, Indonesia) |
title_short |
Sharp bends associated with deep scours in a tropical river: The river Mahakam (East Kalimantan, Indonesia) |
title_full |
Sharp bends associated with deep scours in a tropical river: The river Mahakam (East Kalimantan, Indonesia) |
title_fullStr |
Sharp bends associated with deep scours in a tropical river: The river Mahakam (East Kalimantan, Indonesia) |
title_full_unstemmed |
Sharp bends associated with deep scours in a tropical river: The river Mahakam (East Kalimantan, Indonesia) |
title_sort |
sharp bends associated with deep scours in a tropical river: the river mahakam (east kalimantan, indonesia) |
publishDate |
2014 |
url |
https://research.wur.nl/en/publications/sharp-bends-associated-with-deep-scours-in-a-tropical-river-the-r https://doi.org/10.1002/2013JF002923 |
long_lat |
ENVELOPE(-136.672,-136.672,68.833,68.833) |
geographic |
Mackenzie Delta |
geographic_facet |
Mackenzie Delta |
genre |
Mackenzie Delta |
genre_facet |
Mackenzie Delta |
op_source |
Journal of Geophysical Research: Earth Surface 119 (2014) 7 ISSN: 2169-9003 |
op_relation |
https://edepot.wur.nl/332156 https://research.wur.nl/en/publications/sharp-bends-associated-with-deep-scours-in-a-tropical-river-the-r doi:10.1002/2013JF002923 |
op_rights |
info:eu-repo/semantics/restrictedAccess Wageningen University & Research |
op_doi |
https://doi.org/10.1002/2013JF002923 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
119 |
container_issue |
7 |
container_start_page |
1441 |
op_container_end_page |
1454 |
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1789968337018552320 |