Influence of tides, bathymetry, lithology and regional flows on the salinization process in nature area the Rammegors

Abstract

Nature area Rammegors, which has recently been transformed from a fresh inner-dyke nature area to a salt tidal area. Due to this transformation, salt water is infiltrating in a fresh waterlens. This salinisation process is investigated in more detail by two- and three dimensional models together with mearsurements in the area. Zeeland project FRESHEM has provided detailed isohaline maps of the area and Deltares is making transient isohaline maps based on measurements made by an ERT-cable which is situated in Rammegors. These data has been and will be used to investigate which factors; bathymetry, lithology, tides or regional groundwater flow, will have the largest impact on the salinization process in Rammegors. This investigation shows that discretization size has an influence on the speed and spatial distribution of salt plumes. Lithology has the largest influence on the salinization process, followed by bathymetry. Spring and neap tides do differ from the normal tides situation only when bathymetry is not taken into account.

Development of the benthic macrofauna community after tidal restoration at Rammegors: final report

“…The occurrence of brackish conditions a year after tidal inundation could be explained by model simulations of groundwater salinity by Deltares (van de Lageweg et al 2019a). The occurrence of brackish conditions a year after tidal inundation could be explained by model simulations of groundwater salinity by Deltares (America et al 2018). Before inundation, a freshwater lens was present in the Rammegors area.…”