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Fresh-saline groundwater in deltaic and coastal areas

Introduction

Salinisation causes problems for farmers, water managers and nature in many coastal areas of the world. Deltares has in-house databases, numerical modelling techniques, monitoring tools and the knowledge to thoroughly investigate salinisation issues and to implement innovative solutions for a robust proof fresh water supply in the coastal zone.

Threats to the fresh water resources

The process of salinisation will accelerate due to the anticipated sea level rise, climate change,
future land subsidence and especially due to human factors like groundwater extraction and
lowering of differentiated polder water levels. The processes described here for the Dutch situation
prevail in many other deltas and coastal areas. Concluding, not taking any mitigation and/or
adaptation measures will lead to a world-wide increase of salinisation.

Focus on regional and local processes

Deltares researchers investigate the processes of fresh, brackish and saline groundwater in coastal
aquifers on different scales. On a regional scale, the effects of climate change, land, and water use
change and the combined effects of preventive measures on groundwater salinisation are studied.
Other studies give answers on how groundwater concentration
changes affect surface water quality. On a local scale, the
dynamics of fresh rainwater lenses on saline groundwater as a
result of natural or artificial recharge are studied. These lenses
allow agriculture in low-lying areas where shallow groundwater
is very saline. Other research topics are preferential
groundwater flow via sandy layers and boils that connect deep
saline aquifers with shallow aquifers and with fresh surface
water bodies. These preferential flow paths largely contribute to
the salinisation of Dutch low-lying areas. Our knowledge is not
specific for the Netherlands and can be applied in similar deltaic
areas around the world.

Leaflet

Fresh-saline groundwater in deltaic and coastal areas

Overview

Projects
Publications
Literature
News
Contact information

Dutch wiki-site

zoetzout.deltares.nl

More Information

Dr.ir. Gualbert Oude Essink
T 088335 7139
gualbert dot oudeessink at deltares dot nl