The Australian Adelaide metropolitan coastline stretches around 30 kilometres, from Seacliff in the south to Outer Harbor in the North. Whilst the southern end of the coast has notable erosional landforms such as cliffs, wave-cut platforms and shingle beaches, the vast majority of the coastline is depositional. This essay will focus on the depositional sandy beaches and dune systems found along the Adelaide coastline.
             Much of the Adelaide coastline is made up of wide sandy beaches. Beaches are formed when sand is brought on to the beach by waves. This occurs particularly in the summer months when waves are constructional, as seen in diagram 1. The profile of the beach changes due to tidal and waves variation. In winter, as seen in diagram 2, waves are deconstructional, and the beach profile is lowered, resulting in the formation of a berm. Off shore sandbars develop, and the sand returns to the beach again in summer.
             Sand is carried on to the beach by waves and along the beach by the movement of longshore drift. Longshore drift carries the sand along the shore in the direction of the prevailing wind and is responsible for the build-up of sand behind natural features such as headlands, and man-made features such as breakwaters. In diagram 3, the action of longshore drift is shown at Glenelg. Sand is picked up by the waves and moves along the beach in a zig-zag motion. The breakwater interrupts the drift and sand is deposited, resulting in a wide sandy beach south of the breakwater, and a spit forming at the end, with North Glenelg being badly starved of sand. The same build-up of sand south of the breakwater, and shortage of sand to the north occurs at Outer Harbor. This is because of Adelaide's prevailing south-westerly winds which causes a northerly drift of sand along the whole coastline. The net drift of sand is northward at a rate of 30,000 cubic metres per year.
             Along the Adelaide coast, there are small remnant sand dune...