 |
| Titel |
Large-scale suspended sediment transport and sediment deposition in the Mekong Delta |
| VerfasserIn |
N. V. Manh, N. V. Dung, N. N. Hung, B. Merz, H. Apel |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 18, no. 8 ; Nr. 18, no. 8 (2014-08-15), S.3033-3053 |
| Datensatznummer |
250120435
|
| Publikation (Nr.) |
 copernicus.org/hess-18-3033-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| Sediment dynamics play a major role in the agricultural and fishery
productivity of the Mekong Delta. However, the understanding of sediment
dynamics in the delta, one of the most complex river deltas in the world, is
very limited. This is a consequence of its large extent, the intricate system
of rivers, channels and floodplains, and the scarcity of observations. This
study quantifies, for the first time, the suspended sediment transport and
sediment deposition in the whole Mekong Delta. To this end, a quasi-2D
hydrodynamic model is combined with a cohesive sediment transport model. The
combined model is calibrated using six objective functions to represent the
different aspects of the hydraulic and sediment transport components. The
model is calibrated for the extreme flood season in 2011 and shows good
performance for 2 validation years with very different flood characteristics.
It is shown how sediment transport and sediment deposition is differentiated
from Kratie at the entrance of the delta on its way to the coast. The main
factors influencing the spatial sediment dynamics are the river and channel
system, dike rings, sluice gate operations, the magnitude of the floods, and
tidal influences. The superposition of these factors leads to high spatial
variability of sediment transport, in particular in the Vietnamese
floodplains. Depending on the flood magnitude, annual sediment loads reaching
the coast vary from 48 to 60% of the sediment load at Kratie. Deposited
sediment varies from 19 to 23% of the annual load at Kratie in Cambodian
floodplains, and from 1 to 6% in the compartmented and diked floodplains
in Vietnam. Annual deposited nutrients (N, P, K), which are associated with
the sediment deposition, provide on average more than 50% of mineral
fertilizers typically applied for rice crops in non-flooded ring dike
floodplains in Vietnam. Through the quantification of sediment and related
nutrient input, the presented study provides a quantitative basis for
estimating the benefits of annual Mekong floods for agriculture and fishery,
and is an important piece of information with regard to the assessment of the
impacts of deltaic subsidence and climate-change-related sea level rise on
delta morphology. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|