The deposition and storage of sediment-associated phosphorus on the flood plains of two lowland groundwater fed catchments

摘要

Overbank sedimentation can result in the accumulation of sediment-associated nutrients on flood plains. This contribution reports the findings of an investigation of sediment-associated phosphorus (P) fluxes within the catchments of the Rivers Frome and Piddle in Dorset, UK, aimed at quantifying deposition of sediment and P on their flood plains associated with individual flood events. Sediment and P deposition were documented using Astroturf synthetic grass mats. Fractionation of the P content of the sediment provided useful information for identifying P sources in the catchments. Depositional fluxes of total P documented for individual flood plain sites in the study ranged from 0,66 g m"2 year"1 to 19 94 g m"2 year"1. Comparison of the two rivers shows both contrasts in their sediment budgets and the location of P sources within the catchments.