Optimized regulation of the Vistula River at its connection to the sea

The paper deals with the morphodynamics of the artificially engineered outlet of the Vistula River, Poland. The delta is a coastal form typical of semi-closed micro-tidal or non-tidal seas, such as the Baltic Sea. This accumulative sandy form in front of the Vistula mouth constitutes a serious obstacle to the flow of water and sediment at the river-sea interface. Therefore, regulation works need to be carried out periodically. The present mathematical modeling applies the representative flushing discharge accompanied by marine hydrodynamic processes to particular variants of regulation of the Vistula mouth. The envelope method of analyzing the modeled bottom changes is used to formulate practical conclusions. The major findings concern the optimal extension of the breakwaters at the river mouth, sufficient to ensure the outlet patency.