|Hydrochemistry of the phreatic aquifer at Bruges (Belgium)|
Charraf, A.; Walraevens, K.; Beeuwsaert, E.; De Breuck, W. (1999). Hydrochemistry of the phreatic aquifer at Bruges (Belgium), in: De Breuck, W. et al. (Ed.) Proceedings of the 15th Salt-Water Intrusion Meeting Ghent (Belgium), 25-29 May 1998. Natuurwetenschappelijk Tijdschrift, 79(1-4): pp. 154-163
In: De Breuck, W.; Walschot, L. (Ed.) (1999). Proceedings of the 15th Salt-Water Intrusion Meeting Ghent (Belgium), 25-29 May 1998. Natuurwetenschappelijk Tijdschrift, 79(1-4). Natuurwetenschappelijk Tijdschrift: Gent, Belgium. 307 pp., more
In: Natuurwetenschappelijk Tijdschrift. L. Walschot/Natuur- en Geneeskundige Vennootschap: Gent. ISSN 0770-1748, more
|Available in|| Authors |
VLIZ: Proceedings D 
|Document type: Conference paper|
Chemistry; Ground water; Ion exchange; Water mixing; Belgium [Marine Regions]
|Authors|| || Top |
- Charraf, A.
- Walraevens, K., more
- Beeuwsaert, E.
- De Breuck, W., more
A study of the salt-/fresh-water distribution at Bruges has been made. The aquifer is formed mainly by Tertiary sands and by Quaternary sediments, which consist of Pleistocene and Holocene sand, clay and peat. During the Dunkirkian transgressians, salt water infiltrated into the aquifer. This salt water has gradually been replaced by fresh water. The aquifer still contains salt water. Geoelectrical investigations and borings with well loggings have been made. The groundwater quality has been determined. This is shown in cross-sections. The processes that have affected the groundwater chemistry are mainly related to the Quaternary geological history. The main processes are mixing and cation exchange. The former is a simple mixing of sea water with fresh water whereas the latter occurs in two ways. When fresh water replaces salt water in the aquifer, an exchange takes place between Ca2+ ions from the water and exchangeable Na+ ions adsorbed to the sediments. The reverse process takes place when sea water infiltrates in sediments with fresh water: the Na+ ions from the sea water are exchanged for Ca2+ ions adsorbed to the sediments. The distribution of fresh and salt water in the area has been influenced mainly by the lithological composition of the Dunkirkian sediments, and locally also by infiltration of salt water into the aquifer from the maritime Boudewijn Canal.