کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4579160 1630094 2008 14 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Use of environmental isotopes to define the capture zone of a drinking water supply situated near a dredge lake
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Use of environmental isotopes to define the capture zone of a drinking water supply situated near a dredge lake
چکیده انگلیسی

SummaryLake–ground water interactions in the vicinity of a dredge lake (Lake Leis; SW Germany) were studied by means of the stable isotopes (18O, 2H) mainly to determine the capture zone of a pumping well for the drinking water supply to the nearby town of Baden-Baden. The water supply is situated in a Quaternary gravel aquifer of the Rhine Valley. Numerical simulation performed using a two-dimensional water flow model was not able to characterise the capture zone uniquely. Several best fit options were possible by applying the values of hydraulic conductivities obtained from the pumping tests. As a result it was not possible to define whether Lake Leis is situated either completely inside or fully outside of the capture zone. To overcome this problem and to define the shape of the catchment area of the water supply precisely, a two-dimensional water flow and tracer transport model was established using both hydraulic heads and isotope data. The isotope data were applied to determine the proportion of lake water in down-gradient pumping and observation wells. Additionally, the isotope compositions of lake water and those in observation wells, measured as a function of time, were used to determine the mean water velocity (v = 0.6 m/d) along some selected 200 m long flow-paths. Based on known porosity and hydraulic gradient values, a hydraulic conductivity of about k = 6 × 10−4 m/s was determined for the central area down-gradient of the lake. This hydraulic conductivity and the proportion of lake water in the groundwater were used to calibrate a numerical two-dimensional regional scale transport model. The study demonstrates that it is possible to calibrate a water flow model in the vicinity of a dredge lake uniquely, only when stable isotope signals measured in a time series in both the lake and groundwater are taken into consideration. The calibrated model finally enables the capture zone of the production well to be precisely defined.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Hydrology - Volume 362, Issues 3–4, 5 December 2008, Pages 220–233
نویسندگان
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