As the waves, currents and tides contribute significantly in the redistribution of the sediments, supplied to the depositional basin, the rate of these oceanographic physical agents is discussed with sediment distribution and littoral transport in the study area.
Littoral transport plays a major role in the development of certain shoreline features like spits and bars, and is causing considerable coastal erosion and accretion (King, 1974).
The largest natural supplies of sand are the adjacent Pirita River and littoral transport along the coast of the Viimsi Peninsula.
The above description suggests that major inflow of sand to Pirita Beach may occur owing to southward littoral transport of the material eroded from different sections of the Viimsi Peninsula.
The interaction of the river flow and littoral transport has led to the formation of a more or less symmetric (with respect to the river stream) sill in the vicinity of the ends of the groins in the past (Fig.
Major changes in the littoral transport occurred after the construction of Miiduranna Port in the 1970s at an earlier landing place for small fishing boats.
The situation is simpler for bayhead beaches such as Pirita Beach that (i) mainly serve as end points of littoral transport for which the lateral losses owing to alongshore transport are negligible, and (ii) which are subject to small seasonal changes and overall moderate wave activity.
The littoral transport of material eroded from the coast of the Viimsi Peninsula and originating from the Pirita River were the major sand sources.
Major changes in the sand budget occurred when (i) Miiduranna Port and its fairway largely blocked the littoral transport, and (ii) when Pirita Olympic Harbour drastically decreased the river-induced sand transport to the littoral system.