Palaeohydrogeological Data Analysis and Model Testing (PADAMOT)

Palaeohydrogeology of aquifers

There have been more palaeohydrogeological studies of aquifers than of low permeability rocks. Aquifers are more permeable rock formations from which groundwater can be extracted in large quantities. Understanding the history of groundwaters in aquifers is important for managing the resource which will be sustainable in the long term only if extraction of water does not exceed natural recharge. Palaeohydrogeology tells us the ages and origins of groundwaters and helps us to understand how variations of recharge over time have been linked with variations of climate. Having relatively high permeabilities and being mostly at rather shallow depths (<500 metres), aquifers tend to be susceptible to climate-driven impacts and contain groundwaters that might have there for shorter times (groundwater 'residence times' or 'ages') than the major climate cycles in the past. There are also some deeper aquifers where groundwater ages pre-date the last glacial episode which ended about 10,000 years ago. A recent EC-funded study ('PALAEAUX'). has investigated the palaeohydrogeology of European coastal aquifers for which flow regimes and replenishment in the past have been sensitive to climate factors including glaciation, permafrost and sea level change (Edmunds and Milne, 2001).