When and where rivers meet the sea

River mouth areas provide one of the most desired locations for human habitation. Although occupying only a small portion of the total length of the world’s shoreline, river mouths are dynamic and complex with highly variable physical and chemical characteristics.The size, shape, and position of a river’s mouth are dependent on its geologic and hydrologic history. Further, the processes that operate in a river’s mouth are affected by the sea and its currents, tides, and salinity; the river and its discharge and sediment characteristics; and wind generated waves and storm surges. Present-day locations are, geologically speaking, of recent origin because of the rise in sea level that accompanied deglaciation and the sedimentation that followed drowning.