The erosion and redistribution of sediment of the Haringvliet delta after construction of the Haringvliet dam.

Abstract

The aim of the present study was to find out how the sediment of the Haringvliet delta was redistributed. The Haringvliet deltas evolution is driven by river flow, tides and waves. After the closure of the Haringvliet tidal basin by the Haringvliet dam in 1970, both the river influence and the tidal influence in the area decreased. This caused the Haringvliet delta to decrease in size. The present research was conducted with GIS and hydrodynamic depth averaged computer modelling. Bathymetry data of 1970, 1984, 1998 and 2012 were used to analyse current directions and sediment transport for the period 1970 to 2012. The present research showed that after closure mainly tidal currents redistributed sediment from the Haringvliet delta front downdrift. The delta front experienced cross-shore sediment transport in landward direction by wave induced currents. Moreover, storms from the northwest had a large impact by transporting sediment inland. It could be concluded that the Haringvliet delta front migrated inland since 1970. Both calm weather and storm conditions redistributed sediment predominantly cross-shore in landward direction. The large impact of the human interventions in the Haringvliet can give insight into implications of human measures in similar tidal inlets.