| dc.description.abstract | In coastal areas, aquifer salinization is a major risk during large-scale dewatering operations. This risk
is enhanced when extraction wells are used to pump large amounts of water from coastal aquifers.
Underneath an extraction well, the salt-fresh water interface may rise towards the surface. To
prevent salinization of the sub-soil, the rising salt cone needs to be analyzed, and quantified. To
predict the amount and extent of the saline water rise, multiple numerical and analytical methods
are available. This report will assess analytical and numerical solutions to solve this problem, and to
review which method suits best for each operation. To solve the numerical solutions, a modelling
study will be carried out using the MODFLOW code, and MODFLOW extensions: MT3DMS and
SEAWAT2000 v4. These methods will be compared with a focus on (1) the role of density-dependent
flow and (2) the effects of dispersion to the mixing zone. A method will be provided that uses the
numerically light MT3DMS code to predict results of the numerically heavier SEAWAT2000 v4 model.
Using this method, time can be spared when assessing whether the risk of salinization is significant
or not. A correction factor for the MT3DMS model results can be applied, which is dependent on the
vertical distance of the saline water to the extraction well. | |
