Groundwater salinity mapping of the Belgian coastal zone to improve local freshwater storage availability

Dieter Vandevelde,Tommer Vermaas,Gualbert Oude Essink,Marc Van Camp,Perry De Louw,Marios Karaoulis,Joost Delsman,Pieter Pauw,Willem Dabekaussen,Esther Van Baaren,Alexander Vandenbohede,Huits Dominique,Jan Gunnink,Marco De Kleine,Sara Thofte,Rasmus Teilmann,Kristine Walraevens

doi:10.1051/e3sconf/20185400040

Abstract

In the European TOPSOIL project, countries around the North Sea are searching for solutions for climate related threats. They explore the possibilities of using the topsoil layer to solve current and future water challenges. The main objective is to improve the climate resilience of the water management of the topsoil and shallow aquifers in the North Sea region. TOPSOIL is supported by the Interreg VB North Sea Region program in line with priority 3 of the program: ‘Sustainable North Sea Region, protecting against climate change and preserving the environment’. The Belgian part of this project, called FRESHEM for GO-FRESH Vlaanderen (‘FREsh Salt groundwater distribution by Helicopter ElectroMagnetic survey for Geohydrological Opportunities FRESH water supply’), focuses on mapping the salinity distribution of groundwater using airborne electromagnetics and aims to look into a number of measures that could increase the availability of freshwater for agriculture in the polder area. Two pilot projects will evaluate the possibilities for freshwater storage and aims to specify what measures can be taken to achieve this. Together with the other water users and water managers, The Flanders Environment Agency wants to prepare a plan for the realization of one or more pilot projects that can improve the availability of freshwater.

Highlights

Shallow coastal aquifers are vulnerable to climate change and sea-level rise (Cliwat, 2011; Ferguson & Gleeson, 2012; Oude Essink et al, 2010; Vandenbohede et al, 2008)
The summer of 2017 for instance showed in the Belgian coastal plain how urgent water scarcity can be and how fast salinization of the fresh water surface water system can occur in polder areas
To get an overview of the current situation of shallow water resources, the salinization of the coastal aquifer is reinvestigated by airborne electromagnetics

Summary

INTRODUCTION

Shallow coastal aquifers are vulnerable to climate change and sea-level rise (Cliwat, 2011; Ferguson & Gleeson, 2012; Oude Essink et al, 2010; Vandenbohede et al, 2008). Climate change and sea-level rise disturb the fragile balance between fresh and salt water and can lead to a more saline environment. The TOPSOIL project will explore the possibilities of using the shallow aquifer to increase the availability of fresh groundwater. To get an overview of the current situation of shallow water resources, the salinization of the coastal aquifer is reinvestigated by airborne electromagnetics. These results are used in a regional water system analysis where physical conditions, measures and potentials to improve the freshwater availability are investigated. This water system analysis will lead to regional maps showing potentials to apply specific measures to improve the freshwater availability

AIRBORNE SURVEY

Pilot areas

CONCLUSIONS