Netherlands Hydrological modelling Instrument (NHI)
The so-called Netherlands Hydrological modelling Instrument (NHI) includes a module to take into account fresh and saline groundwater in the coastal zone. This paper informs you about this NHI fresh-saline groundwater module, which assesses on a national scale the impact of stresses such as sea level rise, land subsidence, increasing groundwater extraction and changes in natural groundwater recharge on groundwater in the Dutch coastal zone. Modelling results show that the water system significantly becomes more saline these coming 50-100 years, and that water courses need to be flushed more intensively if water boards want to maintain the water quality in the surface water system. This module is ready to play a role in assessing the effectiveness of mitigation and adaptation strategies to make our water system climate proof.
Article: De Lange, W.J., Prinsen, G.F., Hoogewoud, J.C., Veldhuizen, A., Verkaik, J., Oude Essink, G.H.P., van Walsum, P.E.V., Delsman, J.R., Hunink, J.C., Massop, H.T.L., Kroon, T., 2014. An operational, multi-scale, multi-model system for consensus-based, integrated water management and policy analysis: The Netherlands Hydrological Instrument. Environmental Modelling & Software 59, 98–108, doi: 10.1016/j.envsoft.2014.05.009
More information: Jarno Verkaik, Joost Delsman or Gualbert Oude Essink
Research on salinisation processes in the Province of Zeeland
The fresh water resources in the groundwater system of the coastal province of Zeeland are at present jeopardized by various causes. Floods, droughts, eutrophication and salinisation of the ground and surface waters are some pressing topics. Moreover, sea level rise and climate change threaten the groundwater system even more. Water management in the province should anticipate on these changes. The province has initiated a study to get a better insight in the salinisation processes in the top system. The main goal is to analyse what measurements are effective in mitigating the salinisation of the water system. Special attention is given to the so-called rainwater lenses in agriculture plots. Agricultural crops depend on these shallow vulnerable water systems which float upon brackish groundwater and vary over the season in thickness.
Research on salinisation processes in the Province of Zuid-Holland
Large parts of the Province Zuid-Holland, the Netherlands, are situated several metres below mean sea level. Saline groundwater from the North Sea and from deep marine fine-grained deposits intrudes the upper aquifers. Natural processes and anthropogenic events of land surface settling, that have been going on for nearly a millennium, cause the salinisation of the subsoil. In addition, future sea level rise and land subsidence are expected to jeopardise the groundwater system even more. Water managers are concerned about the future state of this dynamic groundwater system during the coming 100 years. A 3-dimensional model was constructed to quantify changes in the groundwater system. The model predicts that past land subsidence and sea level rise lead to an accelerated inflow of saline groundwater towards the coastal groundwater system in the next centuries.
Article: Oude Essink, G.H.P., E.S. van Baaren, and P.G.B. de Louw. 2010. Effects of climate change on coastal groundwater systems: A modeling study in the Netherlands, Water Resour. Res., 46, W00F04, doi: 10.1029/2009WR008719.
Presentation:: Oude Essink G.H.P, Van Baaren E.S., De Louw P.G.B., 2010, Effects climate change on coastal groundwater systems, focus on the Rhine Delta, Proceedings Deltas in Times of Climate Change, Rotterdam, The Netherlands, Sept-Oct. 2010 download
Local phenomena: saline boils and rainwater lenses
Louw, P.G.B., de, van der Velde, Y., and van der Zee, S.E.A.T.M. 2011. Quantifying water and salt fluxes in a lowland polder catchment dominated by boil seepage: a probabilistic end-member mixing approach, Hydrol. Earth Syst. Sci., 15, 2101-2117
Louw, P.G.B., de, Oude Essink, G.H.P., Stuyfzand, P.J., Zee, van der, S.E.A.T.M., 2010, Upward groundwater flow in boils as the dominant mechanism of salinization in deep polders, The Netherlands, J. Hydrol. 394, 494-506.
Shallow rainwater lenses
Louw, P.G.B., de, Eeman, S., Siemon, B., Voortman, B.R., Gunnink, J., van Baaren, E.S., and Oude Essink, G.H.P., 2011, Shallow rainwater lenses in deltaic areas with saline seepage, Hydrol. Earth Syst. Sci., 15, 3659-3678.
Peer-reviewed articles fresh-saline modelling case-studies