ZMT - Leibniz Zentrum für Marine Tropenforschung

Project Summary

Groundwater is the primary drinking water supply of billions of people worldwide. Groundwater is under pressure globally due to extensive water abstractions. Proximity to coasts amplifies these pressures due to potential sea water intrusion that can endanger groundwater quality. It is unclear how climate change (changing potential groundwater recharge), as well as rising sea levels, will alter coastal groundwater dynamics, i.e., submarine groundwater discharge and seawater intrusion. Factors such as groundwater recharge & extraction, hydraulic gradients, permeabilities, water densities, and oceanic activity (e.g., tidal pumping and wave setup) impact coastal groundwater dynamics. While recently, global models emerged that mapped controls of coastal groundwater fluxes at global scale, those are still static and transient information is missing.

The COASTGUARD project will utilize and extent the G³M global groundwater model to assess coastal groundwater flows and, in parallel, improve the current parameterization of global groundwater models and quantify uncertainties between the global and local scale. This will significantly help to further understand and improve these kinds of models.

Furthermore, it allows us to improve our understanding of coastal groundwater dynamics at  a  global  scale  and  highlight regions with particularly strong implications of climate change on groundwater availability and thus drinking water resources and groundwater discharge in coastal areas.