Groundwater circulation in the allochthonous limestone units between Lake Girdev and Kazanpınarı Spring, Antalya, southwestern Turkey

The aim of the study is to investigate the interaction between waters of Lake Girdev and groundwater in the allochthonous limestone units exposed in the area between Lake Girdev and Kazanpinari Spring, southwestern Turkey. The features analyzed include the flow direction and apparent groundwater velocity, their relationship with Lake Girdev, and the effect of lithological and structural features on the groundwater circulation. The results of a fluorescein tracer test indicate that groundwater flows east-northeast and the apparent flow velocity ranges from 26.2 to 35.6mh super(-1) between the injection site and various observation points. Tritium data suggest that the water of Lake Girdev and groundwater are probably similar in age, and oxygen-18 isotope data indicate that water derived from Lake Girdev is the main source of recharge to the aquifer. The aquifer is fed not only by Lake Girdev but also by rainfall percolating through allochthonous limestones; together, these provide the discharge of springs in Elmali Polje. The permeability of the allochthonous limestone aquifer has been enhanced as a result of jointing and faulting.Original Abstract: Cette etude avait pour but d'analyser les relations entre les eaux du lac Girdev et les eaux souterraines des unites calcaires allochtones affleurant dans la region comprise entre le lac Girdev et les sources de Kazanpinari (sud-ouest de la Turquie). Les phenomenes etudies concernent la direction de l'ecoulement et la vitesse apparente de l'ecoulement souterrain, les relations avec le lac Girdev et le role de la lithologie et de la structure sur les ecoulements. Les resultats d'un tracage a la fluoresceine indiquent que l'eau souterraine s'ecoule vers le nord-est et que la vitesse apparente moyenne est comprise entre 26.2 et 35.6mh super(-1), entre le point d'injection et les differents points d'emergence. Les donnees de tritium suggerent que l'eau du lac de Girdev et l'eau souterraine ont probablement le meme age; les donnees d'oxygene-18 indiquent que l'eau du lac Girdev est la principale alimentation de l'aquifere. L'aquifere est alimente non seulement par le lac Girdev, mais aussi par les precipitations alimentant l'infiltration dans les calcaires allochtones; ces deux types de recharge assurent l'ecoulement aux sources du polje d'Elmali. La permeabilite dans l'aquifere des calcaires allochtones a ete interpretee comme etant due aux fissures et aux failles.