Recharge and Turnover of Groundwater in Coastal Aquifers with Emphasis on Hydrochemistry and Isotopes

Abstract

Coastal aquifers are globally subject to considerable stress. The population density is often high in coastal areas, and in addition, the coastal plains often have good agricul-tural soils demanding irrigation. While a portion of the irrigation can be provided by rivers, local groundwater is also used adding to the water requirement. Many coastal aquifers are large with a slow turnover of the groundwater and recharge is difficult to assess. This review is aimed at giving an overview of the hydrochemistry with an emphasis of giving insight into the groundwater recharge and the sustainability of the groundwater quality. The past climate history has given an imprint of hydrochemistry of especially coastal aquifers.