Upward groundwater flow in boils as the dominant mechanism of salinization in deep polders, the Netherlands

Autor: P.G.B. de Louw, G.H.P. Oude Essink, Pieter J. Stuyfzand, S.E.A.T.M. van der Zee
Jazyk: angličtina
Rok vydání: 2010
Předmět:
Evaporite
Groundwater flow
chloride
Water flow
hydrology
holoceen
Seepage
rhine-meuse delta
groundwater
Earth and Planetary Sciences (miscellaneous)
Leerstoelgroep Bodemnatuurkunde
Saltwater intrusion
Preferential flow
Water Science and Technology
geography.geographical_feature_category
seepage
Salinization
Leerstoelgroep Bodemnatuurkunde
ecohydrologie en grondwaterbeheer
Soil Physics
ecohydrologie en grondwaterbeheer
quality
sand boils
Geology
saline water
groundwater quality
zuid-holland
Chloride load
water flow
Aquifer
surface-water
soil
discharge
saltwater intrusion
kwel
Hydrology
geography
WIMEK
aquifer
Deep polder
temperature
Saline water
zout water
grondwaterkwaliteit
polders
Ecohydrology and Groundwater Management
grondwater
Soil Physics
Ecohydrology and Groundwater Management
holocene
Surface water
waterstroming
Groundwater
Boils
Zdroj: Journal of Hydrology 394 (2010) 3-4
Journal of Hydrology, 394(3-4), 494. Elsevier
Journal of Hydrology, 394(3-4), 494-506
ISSN: 0022-1694
DOI: 10.1016/j.jhydrol.2010.10.009
Popis: As upward seepage of saline groundwater from the upper aquifer is leading to surface water salinization of deep polders in the Netherlands, we monitored the processes involved in the Noordplas Polder, a typical deep polder. Our results show three types of seepage: (1) diffuse seepage through the Holocene confining layer, (2) seepage through paleochannel belts in the Holocene layer, and (3) intense seepage via localized boils. They differ with regard to seepage flux, chloride concentration, and their location in the polder; thus, their contributions to surface water salinization also differ. Permeable, sandy paleochannel belts cut through the lower part of the Holocene layer, resulting in higher seepage fluxes than the diffuse seepage through the Holocene layer where there are no paleochannels. The average chloride concentration of paleochannel seepage is about 600 mg/l, which is sixfold higher than the average concentration of diffuse seepage. The highest seepage fluxes and chloride concentrations are found at boils, which are small vents in the Holocene layer through which groundwater preferentially discharges at high velocities. This results in upconing of deeper and more saline groundwater, which produces an average chloride concentration of 1100 mg/l. Despite the fact that seepage fluxes are difficult to measure, we were able to calculate that boils contribute more than 50% of the total chloride load entering the Noordplas Polder and they therefore form the dominant salinization pathway.
Databáze: OpenAIRE
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