TY - JOUR
T1 - Groundwater arsenic content related to the sedimentology and stratigraphy of the Red River delta, Vietnam
AU - Kazmierczak, Jolanta
AU - Postma, Dieke
AU - Dang, Trung
AU - Hoang, Hoan Van
AU - Larsen, Flemming
AU - Hass, Andreas Elmelund
AU - Hoffmann, Andreas Hvam
AU - Fensholt, Rasmus
AU - Pham, Nhan Quy
AU - Jakobsen, Rasmus
N1 - Funding Information:
This study was supported by ERC Advanced Grant # 338972 . Students from the Hanoi University of Mining and Geology are thanked for help during the geophysical field surveys. Aleksandra Koprowska is thanked for help producing the boxplots.
Funding Information:
This study was supported by ERC Advanced Grant # 338972. Students from the Hanoi University of Mining and Geology are thanked for help during the geophysical field surveys. Aleksandra Koprowska is thanked for help producing the boxplots.
Publisher Copyright:
© 2022 The Authors
PY - 2022/3/25
Y1 - 2022/3/25
N2 - Arsenic (As) is highly toxic and over 100 million people living on the floodplains of Asia are exposed to excessive groundwater As. A very large spatial variability over small distances has been observed in the groundwater As concentrations. Advances in the prediction of the As distribution in aquifers would support drinking water management. The application of remote sensing of geomorphic paleo river features combined with geological, geophysical and archeological data and available groundwater As measurements may be used to predict groundwater As levels in rural areas, as shown by the example from the Red River delta, Vietnam. Groundwater in sediments deposited in the marine environment is low in As, probably due to the precipitation of As in sulfide minerals under anoxic conditions. Groundwater As levels in freshwater alluvial deposits in undisturbed floodplain areas are slightly increased and the highest As concentrations are associated with meander belts. The meander belts remain clearly visible in remote sensing and may well reflect the youngest preserved alluvial sediments. High As levels in the meander belt aquifers are probably related to the availability of highly reactive organic matter and consequent reduction of iron oxyhydroxides and As release. Furthermore, given similar hydrogeological conditions, the extent of flushing of As from the youngest alluvial sands is limited compared to the older Pleistocene sands. Even within abandoned meander belts a high spatial variability of As concentrations was observed. The younger channel belts (<1 ka BP) and old Holocene aquifers below undisturbed floodplain environments deposited during a period with high sea level host groundwater enriched in As. Low As groundwater is found in sandy channel belts deposited during the regression of the sea and in Pleistocene islands preserved within the floodplain. The decisive influence of the depositional environment of the aquifer sediments on groundwater As content is revealed.
AB - Arsenic (As) is highly toxic and over 100 million people living on the floodplains of Asia are exposed to excessive groundwater As. A very large spatial variability over small distances has been observed in the groundwater As concentrations. Advances in the prediction of the As distribution in aquifers would support drinking water management. The application of remote sensing of geomorphic paleo river features combined with geological, geophysical and archeological data and available groundwater As measurements may be used to predict groundwater As levels in rural areas, as shown by the example from the Red River delta, Vietnam. Groundwater in sediments deposited in the marine environment is low in As, probably due to the precipitation of As in sulfide minerals under anoxic conditions. Groundwater As levels in freshwater alluvial deposits in undisturbed floodplain areas are slightly increased and the highest As concentrations are associated with meander belts. The meander belts remain clearly visible in remote sensing and may well reflect the youngest preserved alluvial sediments. High As levels in the meander belt aquifers are probably related to the availability of highly reactive organic matter and consequent reduction of iron oxyhydroxides and As release. Furthermore, given similar hydrogeological conditions, the extent of flushing of As from the youngest alluvial sands is limited compared to the older Pleistocene sands. Even within abandoned meander belts a high spatial variability of As concentrations was observed. The younger channel belts (<1 ka BP) and old Holocene aquifers below undisturbed floodplain environments deposited during a period with high sea level host groundwater enriched in As. Low As groundwater is found in sandy channel belts deposited during the regression of the sea and in Pleistocene islands preserved within the floodplain. The decisive influence of the depositional environment of the aquifer sediments on groundwater As content is revealed.
KW - Arsenic hazard maps
KW - Groundwater arsenic contamination
KW - Hydrogeological processes
KW - Remote sensing
KW - Sedimentary floodplain structure
UR - http://www.scopus.com/inward/record.url?scp=85122635508&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2021.152641
DO - 10.1016/j.scitotenv.2021.152641
M3 - Article
AN - SCOPUS:85122635508
SN - 0048-9697
VL - 814
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 152641
ER -
