Comte J.C. auteur aut IRD Banton O. auteur aut IRD Join Jean-Lambert auteur aut IRD Cabioch Guy auteur aut IRD text journalArticle eng text/pdf born digital access In small islands, a freshwater lens can develop due to the recharge induced by rain. Magnitude and spatial distribution of this recharge control the elevation of freshwater and the depth of its interface with salt water. Therefore, the study of lens morphology gives useful information on both the recharge and water uptake due to evapotranspiration by vegetation. Electrical resistivity tomography was applied on a small coral reef island, giving relevant information on the lens structure. Variable density groundwater flow models were then applied to simulate freshwater behavior. Cross validation of the geoelectrical model and the groundwater model showed that recharge exceeds water uptake in dunes with little vegetation, allowing the lens to develop. Conversely, in the low-lying and densely vegetated sectors, where water uptake exceeds recharge, the lens cannot develop and seawater intrusion occurs. This combined modeling method constitutes an original approach to evaluate effective groundwater recharge in such environments. specialized NOUVELLE CALEDONIE 062 46 W06601 2010 0043-1397 https://www.documentation.ird.fr/hor/fdi:010049640 10.1029/2009wr008058 0043-1397 [F B010049640] https://www.documentation.ird.fr/hor/fdi:010049640 https://www.documentation.ird.fr/intranet/publi/2010/07-2/010049640.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2010-08-03 2021-11-01 fdi:010049640 fre