%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Baudron, P.
%A Barbecot, F.
%A Gillon, M.
%A Arostegui, J. L. G.
%A Travi, Y.
%A Leduc, Christian
%A Castillo, F. G.
%A Martinez-Vicente, D.
%T Assessing groundwater residence time in a highly anthropized unconfined aquifer using bomb peak C-14 and reconstructed irrigation water H-3
%D 2013
%L fdi:010061216
%G ENG
%J Radiocarbon
%@ 0033-8222
%K ESPAGNE
%M ISI:000325752100085
%N 2-3
%P 993-1006
%U https://www.documentation.ird.fr/hor/fdi:010061216
%> https://www.documentation.ird.fr/intranet/publi/2013/11/010061216.pdf
%V 55
%W Horizon (IRD)
%X Radiocarbon decay is rarely used to assess the residence time of modern groundwater due to the low resolution of its long half-life in comparison to the expected range of ages. Nonetheless, the modern C-14 peak induced by the nuclear bomb tests traces efficiently the impacts of recent human activities on groundwater recharge, as well as for tritium. A simple lumped parameter model (LPM) was implemented in order to assess the interest of C-14 and H-3 nuclear peaks in a highly anthropized aquifer system of southeastern Spain under intense agricultural development. It required i) to assess a correction factor for modern C-14 activities and ii) to reconstruct the H-3 recharge input function, affected by irrigation. In such a complex hydrogeological context, an exponential model did not provide satisfying results for all samples. A better solution was reached by taking into account the qualitative recent variation of the recharge rates into a combined exponential flow and piston flow model. Apart from presenting an uncommon approach for C-14 dating of modern groundwater, this study highlights the need of considering not only the variation of the tracer but also the variability of recharge rates in LPMs.
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