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| Titel |
Hydro- and sediment dynamics in the estuary zone of the Mekong Delta: case study Dinh An estuary. |
| VerfasserIn |
Anh Tuan Tran, Heiko Thoss, Nicolas Gratiot, Philippe Dussouillez, Guillaume Brunier, Heiko Apel |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250141578
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| Publikation (Nr.) |
 EGU/EGU2017-5108.pdf |
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| Zusammenfassung |
| The Mekong River is the tenth largest river in the world, covers an area of 795,000 km2,
4400km in length, the main river flows over the six countries including: China, Myanmar,
Thailand, Laos, Cambodia and Vietnam. Its water discharge is 470 km3year−1 and the
sediment discharge is estimated about 160 million ton year−1. The sediment transported by
the Mekong River is the key factor in the formation and development of the delta. It is a vital
factor for the stability of the coastline and river banks. Furthermore it compensates land
subsidence by floodplain deposition, and is the major natural nutrient source for agriculture
and aquaculture. However, only a few studies were conducted to characterize and
quantify sediment properties and process in the Delta. Also the morphodynamic
processes were hardly studied systematically. Hence, this study targets to fill some
important and open knowledge gaps with extensive field works that provide important
information about the sediment properties and hydrodynamic processes in different
seasons
Firstly three field survey campaigns are carried out along a 30 km section of the Bassac
River from the beginning of Cu Lao Dung Island to Dinh An estuary in 2015 and 2016.
During the field campaign, the movement of the salt wedge and the turbidity were monitored
by vertical profiles along the river, as well as discharge measurements by ADCP were carried
out at three cross sections continuously for 72 hours. The extension of the salt wedge in the
river was determined, along with mixing processes. The movement and dynamics observed
under different flow conditions indicate that sediment was pumped during low flow upwards
the river, while during high flow net transport towards the sea dominated. Also a distinct
difference in the sediment properties in the different seasons was observed, with a
general tendency towards a higher proportion of coarser particles in the high flow
season.
These quantitative results give insights into the important sediment dynamics in the
estuary and the vital sediment transport towards the coast of the Mekong delta, which is the
basis for morphological stability of the coast. The results of the field campaigns
will be used for the development of a detailed 3D sediment transport model (Delft
3D) for the quantification of the morphodynamic processes at Dinh An estuary. |
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