The transport and fluvial redistribution of Chernobyl-derived radiocaeisum within the River Wye basin, UK.
Relatively little attention has been given to the long term prospect of fluvial transport processes redistributing Chernobyl-derived radiocaesium within the UK. Work undertaken within the Wye basin, central Wales, demonstrates a complex distribution of fallout at the catchment scale, with the bulk of the deposition concentrated in a narrow north-south band, situated in the west central areas of the basin, which contained in excess of 1500 Bq m(-2) of (134)Cs. Fluvial transport and redistribution of this material was demonstrated by river sampling during the winter of 1988/89, when the radiocaesium content of suspended sediment transported by the River Wye (approximately 30-50 mBq g(-1) of (137)Cs) remained 3-5 times higher than pre-Chernobyl levels. Floodplain reaches displayed variable levels of secondary contamination, dependent upon the upstream supply of radiocaesium and local morphological controls. Accordingly, the highest (134)Cs inventories within the basin (> 6000 Bq m(-2)) were associated with rapidly accreting floodplain sites. A number of these sites experienced only limited amounts of direct atmospheric fallout. The importance of fluvial redistribution as a secondary contamination mechanism is thus highlighted.
Rowan
J S
JS
Institute of Environmental and Biological Sciences, Lancaster University, UK.
Walling
D E
DE
D000059:Accidents; D002588:Cesium Radioisotopes / Q000032:analysis*; D005843:Geography; D009688:Nuclear Reactors; D014455:Ukraine; D006113:United Kingdom; D014875:Water Pollutants, Radioactive / Q000032:analysis*
D002588:Cesium Radioisotopes; D014875:Water Pollutants, Radioactive