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Origin of shallow groundwater of Csepel Island (south of Budapest, Hungary, River Danube): isotopic and chemical approach
Author(s) -
Fórizs I.,
Berecz T.,
Molnár Z.,
Süveges M.
Publication year - 2005
Publication title -
hydrological processes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.222
H-Index - 161
eISSN - 1099-1085
pISSN - 0885-6087
DOI - 10.1002/hyp.5971
Subject(s) - groundwater , meteoric water , hydrology (agriculture) , aquifer , radiocarbon dating , precipitation , geology , stable isotope ratio , glacial period , environmental science , geomorphology , geography , paleontology , physics , quantum mechanics , meteorology , geotechnical engineering
The shallowest aquifer of the alluvial Csepel Island is used for drinking water supply for Budapest and the surrounding villages. A previous two‐dimensional hydraulic model failed to explain many observations; therefore, a three‐dimensional hydraulic model was constructed using the software application MODFLOW. Isotopic and hydrogeochemical investigations were carried out during the period 1998 to 2002 in order to provide model data. Four water sources have been identified, having different isotopic (and chemical) characteristics. Danube water is characterized by seasonally varying δ 18 O values: its unweighted mean δ 18 O value is −10·9‰ for the years 1998 to 2002. The most negative δ 18 O values occur in late spring and summertime. Average tritium content is 20 TU. Infiltrated precipitation has δ 18 O values between −9·0 and −9·5‰. The average tritium content of the precipitation is 10 TU, and that of infiltrated precipitation must be close to this value and about half that of the Danube. The δ 18 O value of lake water is > −9·0‰. Its stable isotope composition plots on the right side of the local meteoric water line on the δD–δ 18 O diagram. Ascending deep groundwater (sampled depth of 20–140 m) has δ 18 O values between −12·0 and −13·5‰. Its radiocarbon age is between 16 000 and 30 000 years BP , probably infiltrated during and around the last glacial maximum (Würm III) period of the latest glaciation. Copyright © 2005 John Wiley & Sons, Ltd.