Abandonment and rapid infilling of a tide-dominated distributary channel at 0.7 ka in the Mekong River Delta

AbstractThe Ba Lai distributary channel of the Mekong River Delta was abandoned and infilled with sediment during the Late Holocene, providing a unique opportunity to investigate the sediment fill, timing and mechanisms of channel abandonment in tide-dominated deltaic systems. Based on analysis and age dating of four sediment cores, we show that the channel was active since 2.6 ka and was abandoned at 0.7 ka as marked by the abrupt disappearance of the sand fraction and increase in organic matter and sediment accumulation rate. We estimate that the channel might have been filled in a time range of 45–263 years after detachment from the deltaic network, with sediment accumulation rates of centimetres to decimetres per year, rapidly storing approximately 600 Mt of organic-rich mud. We suggest that the channel was abandoned due to a sediment buildup favoured by an increase in regional sediment supply to the delta. This study highlights that mechanisms for abandonment and infilling of tide-dominated deltaic channels do not entirely fit widely used models developed for fluvial-dominated environments. Their abandonment might be driven by autogenic factors related to the river-tidal and deltaic dynamics and favoured by allogenic factors (e.g., human impact and/or climate change).

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Bottom morphology in the Song Hau distributary channel, Mekong River Delta, Vietnam

Continental Shelf Research ◽

10.1016/j.csr.2017.05.010 ◽

2017 ◽

Vol 147 ◽

pp. 51-61 ◽

Cited By ~ 11

Author(s):

Mead A. Allison ◽

H. Dallon Weathers ◽

Ehab A. Meselhe

Keyword(s):

River Delta ◽

Mekong River ◽

Mekong River Delta ◽

Distributary Channel

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Mid-Holocene mangrove succession and its response to sea-level change in the upper Mekong River delta, Cambodia

Quaternary Research ◽

10.1016/j.yqres.2012.07.001 ◽

2012 ◽

Vol 78 (2) ◽

pp. 386-399 ◽

Cited By ~ 38

Author(s):

Zhen Li ◽

Yoshiki Saito ◽

Limi Mao ◽

Toru Tamura ◽

Zhen Li ◽

...

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Sedimentary Environment ◽

River Delta ◽

Sediment Supply ◽

Mekong River ◽

Tidal Range ◽

Mangrove Species ◽

Mekong River Delta ◽

Core Site

AbstractMiddle Holocene vegetation and mangrove successions are clearly evident in the palynological records of two cores from the upper Mekong River delta in Cambodia. Spanning from ~ 9.4 to 6.3 cal ka BP, the cores mainly record a transgressive sequence from floodplain freshwater marsh to tidal flat, which was overlain by mangrove. Corresponding to the decelerated sea-level rise at ~ 8.3 cal ka BP, pioneer mangrove species Sonneratia alba and Sonneratia caseolaris appeared in the sediments, and then was replaced by regressive mangrove succession containing upward-increasing abundances of Rhizophora apiculata and Bruguiera spp. High salinity- and flooding-tolerant community S. alba was developed at the western core site PSG at ~ 8.2 cal ka BP, and the eastern core site PK at ~ 7.5 cal ka BP. The time difference of S. alba appearance between the two sites might be resulted from the complexity of sedimentary environment, where a higher sediment supply was provided to the western floodplain than to the eastern floodplain. After 7.5 cal ka BP, aggradational stacking of intertidal sediments, of which the thickness is larger than the present maximum tidal range, may have resulted from continuous sea-level rise during 7.5–7.0 cal ka BP.

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Impacts of Climate Shock Response Measures on Poverty Vulnerability of Farmer Households in the Mekong River Delta

Journal of Economic Development ◽

10.24311/jed/2016.23.3.03 ◽

2016 ◽

Vol 23 (3) ◽

pp. 143-160

Author(s):

TRAN DAI NGHIA ◽

DOAN MINH THU ◽

LE TRONG HAI ◽

DINH PHI HO

Keyword(s):

River Delta ◽

Mekong River ◽

Mekong River Delta ◽

Shock Response ◽

Response Measures

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Pigment Preservation in Lake Sediments: A Comparison of Sedimentary Environments in Trout Lake, Wisconsin

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f91-061 ◽

1991 ◽

Vol 48 (3) ◽

pp. 472-486 ◽

Cited By ~ 39

Author(s):

James P. Hurley ◽

David E. Armstrong

Keyword(s):

Accumulation Rate ◽

Sediment Cores ◽

Sediment Accumulation ◽

Sediment Surface ◽

Water Interface ◽

Sedimentary Pigments ◽

Sedimentary Environments ◽

Trout Lake ◽

Secondary Carotenoids ◽

Β Carotene

Fluxes and concentrations of a phorbins and major algal carotenoids were quantified in sediment trap material and sediment cores from two basins of Trout Lake, Wisconsin (TrDH and TrAB). The basins were chosen to contrast the influence of oxygen content at the sediment–water interface (TrDH, oxic and TrAB, reducing), sediment accumulation rate, and focusing. Pigment diagenesis occurred in both basins, but transformations and destruction were more extensive in TrDH. Although untransformed chlorophyll a was the major phorbin deposited at the sediment surface of both basins (51–64 mol%), pigment destruction, coupled with transition to pheophytin, accounted for substantial losses, especially in oxic TrDH sediments. Fucoxanthin, peridinin, and diadinoxanthin, despite representing > 70% of the deposited carotenoid flux, were substantially degraded or transformed in both basins. However, preservation was relatively high for secondary carotenoids, such as diatoxanthin and β-carotene, and for a major cryptomonad pigment, alloxanthin. Residual profiles in sediments show that pigment sedimentation from the epilimnion and accumulation in the permanent sediments are not directly related and that diagenesis must be considered in interpreting sedimentary pigments.

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Climate change impacts on rice productivity in the Mekong River Delta

Applied Geography ◽

10.1016/j.apgeog.2018.12.004 ◽

2019 ◽

Vol 102 ◽

pp. 71-83 ◽

Cited By ~ 10

Author(s):

Caitlin Kontgis ◽

Annemarie Schneider ◽

Mutlu Ozdogan ◽

Christopher Kucharik ◽

Van Pham Dang Tri ◽

...

Keyword(s):

Climate Change ◽

Climate Change Impacts ◽

River Delta ◽

Mekong River ◽

Mekong River Delta ◽

Rice Productivity

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Landcover classification over the Mekong river delta using ERS and RADARSAT SAR images

IGARSS'97. 1997 IEEE International Geoscience and Remote Sensing Symposium Proceedings. Remote Sensing - A Scientific Vision for Sustainable Development ◽

10.1109/igarss.1997.609209 ◽

2002 ◽

Cited By ~ 1

Author(s):

S.C. Liew ◽

S.P. Kam ◽

T.P. Tuong ◽

P. Chen ◽

V.Q. Minh ◽

...

Keyword(s):

River Delta ◽

Mekong River ◽

Sar Images ◽

Mekong River Delta ◽

Landcover Classification

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The Toba Volcanic Event and Interstadial/Stadial Climates at the Marine Isotopic Stage 5 to 4 Transition in the Northern Indian Ocean

Quaternary Research ◽

10.1006/qres.2001.2291 ◽

2002 ◽

Vol 57 (1) ◽

pp. 22-31 ◽

Cited By ~ 61

Author(s):

Hartmut Schulz ◽

Kay-Christian Emeis ◽

Helmut Erlenkeuser ◽

Ulrich von Rad ◽

Christian Rolf

Keyword(s):

Arabian Sea ◽

Water Productivity ◽

Ice Core ◽

Sediment Cores ◽

Sediment Accumulation ◽

Sediment Supply ◽

Volcanic Event ◽

Additional Support ◽

Marine Isotope Stage 5 ◽

A Minor

AbstractThe Toba volcanic event, one of the largest eruptions during the Quaternary, is documented in marine sediment cores from the northeastern Arabian Sea. On the crest of the Murray Ridge and along the western Indian continental margin, we detected distinct concentration spikes and ash layers of rhyolithic volcanic shards near the marine isotope stage 5–4 boundary with the chemical composition of the “Youngest Toba Tuff.” Time series of the Uk′37-alkenone index, planktic foraminiferal species, magnetic susceptibility, and sediment accumulation rates from this interval show that the Toba event occurred between two warm periods lasting a few millennia. Using Toba as an instantaneous stratigraphic marker for correlation between the marine- and ice-core chronostratigraphies, these two Arabian Sea climatic events correspond to Greenland interstadials 20 and 19, respectively. Our data sets thus depict substantial interstadial/stadial fluctuations in sea-surface temperature and surface-water productivity. We show that variable terrigenous (eolian) sediment supply played a crucial role in transferring and preserving the productivity signal in the sediment record. Within the provided stratigraphic resolution of several decades to centennials, none of these proxies shows a particular impact of the Toba eruption. However, our results are additional support that Toba, despite its exceptional magnitude, had only a minor impact on the evolution of low-latitude monsoonal climate on centennial to millennial time scales.

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