Aperesyp (пересыпь), is a Russianhydrological term name for amouth bar, an element of adeltaic system. Aperesyp or mouth bar is a deposit of thesediment transported by the river—i.e., ashoal or sandbar—at theriver mouth, typically in mid-channel.[1][2] This narrow sandbar rises above the water level like aspit and separates aliman (a Russian word for anyestuarylagoon on the Black Sea coast) from the open water.
Unlike atombolo, a mouth bar/peresyp seldom forms a contiguous strip and instead usually has one or more channels (girlo (гирло) in Russian) that connect the lagoon/liman to the sea.[3][4]
Like a spit, aperesyp is formed by actions ofsurf zone currents from sand, gravel/pebbles, and crushed shells as a result of longitudinal (longshore drift) or transverse transport ofsediment.[4] Aperesyp may form when two spits on the two sides of aliman grow and meet.[5] These channels can then close and re-open cyclically with changes in current and saturation. And water can seep through or spill over a closedperesyp. The seawater within the enclosed and shallowliman will thenevaporate, raising the lagoon'ssalinity. A number ofsalt lakes inCrimea were formed this way.[3]
Aliman orperesyp is classified as "maritime" if formed by sea currents or "fluvial" if bydeltaic action.[6]
A number of locations on the Black Sea coasts ofRussia andUkraine are calledperesyp. ThePeresypskyi Raion (district) [uk] ofOdesa is built on the wide mouth bar that separates theKhadzhibey andKuialnyk estuaries from the Black Sea. Other sites include theAnapa Peresyp [ru] spitTylihul Peresyp [uk] on theTylihul Estuary in Ukraine.
The Black Seaperesypecosystem is unique.[7]
Russianпересыпь is derived from the verb пересыпать, "sprinkle over".
