Area of low, ill-drained ground on a floodplain away from the main channel. It stands slightly lower than adjacent alluvial fans extending from the valley sides, and is below natural levées that rise towards the main channel. It is a site of slow accumulation of silts and clays.
Geography
On a flood plain, a marshy area where floodwater may be confined between the river levées and higher ground. See Takehiko et al. (2006) Geog. Res. 44, 1 on mangroves and backswamps, and Patrick and Ellery (2007) Afr. J. Ecol. 45, 3.