Publication: Effectiveness of different spatial interpolators in estimating heavy metal contamination in shallow groundwater: a case study of arsenic contamination in Hanoi, Vietnam
5
Issued Date
2011-04
Copyright Date
2011-04
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Language
eng
ISSN
1686-5456
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Mahidol University
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Mahidol University
Bibliographic Citation
Environment and Natural Resources Journal. Vol 9, No.1, (April 2011), 31-37
Suggested Citation
Pham Quy Giang, Kanchana Nakhapakorn, กาญจนา นาคะภากร, Achara Ussawarujikulchai Effectiveness of different spatial interpolators in estimating heavy metal contamination in shallow groundwater: a case study of arsenic contamination in Hanoi, Vietnam. Environment and Natural Resources Journal. Vol 9, No.1, (April 2011), 31-37. Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/48061
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Title
Effectiveness of different spatial interpolators in estimating heavy metal contamination in shallow groundwater: a case study of arsenic contamination in Hanoi, Vietnam
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Abstract
Starting from emerging issues of arsenic contamination of groundwater, this study
was conducted in Thanh Tri, a sub-urban district in southeastern side of Hanoi, in order
to: (1) archive comprehensive understandings of arsenic contamination in shallow
groundwater, (2) generate risk map and compare effectiveness of different spatial
interpolation approaches including Kriging, IDW and Radial Basis Function of
Geographic Information System (GIS) in estimating arsenic concentration.
The study found that the concentration of arsenic varied from 4.71µg/L to
394.93µg/L, with an average of 81.92µg/L, far higher than the standard of 10µg/L set
by the World Health Organization. Distinct distributions of arsenic concentrations were
observed for different geographical and geohydrological aspects. High arsenic
concentrations were found mostly in the southwest of the study area and concentrations
decreased gradually in other directions. Regarding geohydrological distribution, the
upper aquifer (Holocene) yielded levels of arsenic ranging from 4.71µg/L to
316.67µg/L; while concentrations in the lower aquifer (Pleistocene) varied between
5.43µg/L and 394.93µg/L. The lowest arsenic concentration was found in the upper
aquifer and the highest concentration was found in lower aquifer.
IDW gave the best prediction with an average error (MAPE) of 32.82%. An
arsenic risk map was created from the IDW method. The map showed groundwater
arsenic contamination and high contaminated areas in up to 99.8% of the district. The
findings from this study will be valuable for households and policymakers to initiate
early mitigation efforts and protect the population from chronic arsenic poisoning