title: Use of a satellite-derived land cover map to estimate transport of radiocaesium to surface waters.
abstract: During the weeks to months after the deposition of radioactive fallout, the initial concentration of radioactivity in rivers and lakes declines as a result of flushing and removal to bottom sediments. In the long-term, however, radioactivity in the water body can remain at significant levels as a result of secondary contamination processes. In particular, it is known that soils contaminated by long-lived radionuclides such as 137Cs and 90Sr provide a significant source to surface waters over a period of years after fallout. Using The Land Cover Map of Great Britain, a satellite-derived land cover map as a surrogate indicator of soil type, we have related catchment land cover type to long-term 137Cs activity concentrations in 27 lakes in Cumbria, UK. The study has shown that satellite-derived maps could be used to indicate areas vulnerable to high long-term 137Cs transport to surface waters in the event of a nuclear accident. In these Cumbrian lakes, it appears that residual 137Cs levels are determined by transfers of 137Cs from contaminated catchments rather than within-lake processes. Only three of the cover types, open shrub moor, bog and dense shrub moor, as identified by the satellite, are needed to explain over 90% of the variation in long-term 137Cs activity concentrations in the lakes, and these have been shown to correlate spatially with occurrence of organic soils.
authors.affiliation: Institute of Freshwater Ecology, River Lab, Wareham, Dorset, UK.
authors.forename: J T
authors.initials: JT
authors.lastname: Smith
authors.forename: D C
authors.initials: DC
authors.lastname: Howard
authors.forename: S M
authors.initials: SM
authors.lastname: Wright
authors.forename: C
authors.initials: C
authors.lastname: Naylor
authors.forename: A M
authors.initials: AM
authors.lastname: Brookes
authors.forename: J
authors.initials: J
authors.lastname: Hilton
authors.forename: B J
authors.initials: BJ
authors.lastname: Howard
mesh_terms: D002588:Cesium Radioisotopes / Q000032:analysis*; D004739:England; D005843:Geography; D006801:Humans; D011847:Radioactive Fallout; D017215:Satellite Communications; D013686:Telemetry; D014872:Water Movements; D014876:Water Pollution / Q000032:analysis*
chemical_list: D002588:Cesium Radioisotopes; D011847:Radioactive Fallout