Effect of groundwater flow on forming arsenic contaminated groundwater in Sonargaon, Bangladesh

► We examine the As-contaminated groundwater flow paths in the Blamaptra delta plain. ► Water recharged from ground surface moves vertically downward beneath flood plain. ► As-hotspot groundwaters are formed on the vertical groundwater flow paths. ► Reducing groundwater condition is not essential fo...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Journal of hydrology (Amsterdam) 2011-11, Vol.409 (3), p.724-736
Hauptverfasser: Nakaya, Shinji, Natsume, Haruyasu, Masuda, Harue, Mitamura, Muneki, Biswas, Dipak Kumar, Seddique, Ashraf A.
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:► We examine the As-contaminated groundwater flow paths in the Blamaptra delta plain. ► Water recharged from ground surface moves vertically downward beneath flood plain. ► As-hotspot groundwaters are formed on the vertical groundwater flow paths. ► Reducing groundwater condition is not essential for the As-hotspot groundwaters. Three-dimensional groundwater flow in Sonargaon, Bangladesh is numerically simulated in order to evaluate the flow paths of As-contaminated drinking groundwater in the Holocene aquifer of the Ganges–Blamaptra–Meghna delta plain over a recent 30-year period. The model indicates that vertical infiltration of surface groundwater into the shallow Holocene aquifer occurs frequently in the Ganges–Blamaptra–Meghna delta plain. It predicts that the water recharged from ground surface moves approximately 10–20 m vertically downward beneath the flood plain, with a gradually increasing horizontal flow, toward the underlying Pleistocene middle mud layer (aquitard). The model also predicts that groundwaters containing highest As concentrations (>700 μg/L) are formed on the vertical groundwater flow paths where surface water recharges the Holocene aquifer and not on the horizontal flow paths. Combining with the groundwater chemistry, reducing groundwater condition is not essential for the As-contaminated groundwater of the studied area in the Ganges delta plain.
ISSN:0022-1694
1879-2707
DOI:10.1016/j.jhydrol.2011.09.006