Géosciences Montpellier-UMR 5243-Bat. 22, Université de Montpellier 2, Place E. Bataillon, 34095 Montpellier Cedex 05, France.
Ground Water. 2013 Jul-Aug;51(4):550-61. doi: 10.1111/j.1745-6584.2012.01011.x. Epub 2012 Nov 19.
Most of the Mediterranean coastal porous aquifers are intensively exploited. Because of climatic and anthropogenic effects, understanding the physical and geological controls on groundwater distribution and flow dynamics in such aquifers is crucial. This study presents the results of a structural investigation of a system located along the coastline of the Gulf of Lions (NW Mediterranean). A key aspect of this study relies on an onshore-offshore integrated approach combining outcrops, seismic profiles, and borehole data analysis. This multidisciplinary approach provides constraints on pore-fluid salinity distribution and stratigraphic organization, which are crucial in assessing the modes of groundwater/seawater exchanges. Onshore, Lower Pliocene deposits dip gently seaward. They are unconformably overlain by Holocene clays in the lagoons. Offshore the Pliocene deposits either outcrop at the seabed or are buried below nonconsolidated sands infilling paleo-valleys. Beneath the lido, the groundwater salinity distribution consists of salty pore water, overlying fresher pore water. Active circulation of groundwater masses is inferred from the geophysical results. In particular, offshore outcrops and paleo-valleys may play an important role in salt water intrusion.
大多数地中海沿海的多孔含水层都在被密集地开采。由于气候和人为因素的影响，了解这些含水层中地下水分布和流动动力学的物理和地质控制因素至关重要。本研究介绍了对位于利翁湾（西北地中海）沿岸系统的结构调查结果。本研究的一个关键方面依赖于陆上-海上综合方法，结合露头、地震剖面和钻孔数据分析。这种多学科方法提供了对孔隙流体盐度分布和地层组织的约束，这对于评估地下水/海水交换的模式至关重要。在陆地上，下上新世沉积物向海倾斜。它们被全新世粘土在泻湖之上不整合覆盖。在海上，上新世沉积物要么在海底露头，要么被填充古河谷的非固结砂埋藏。在丽都浴场下方，地下水的盐度分布由咸孔隙水和淡水组成。从地球物理结果推断出地下水体的活跃循环。特别是，海上露头和古河谷可能在海水入侵中发挥重要作用。
