Geochemical Fingerprinting - Application of Geochemical Tracers to Fluvial Sediment - page 39

Fig. 2.10 Estimated contributions of sediment to a wetland from a delineated land-use categories
and b soil types. c Estimated age of wetland sediments using two different models. Sedimentation
rates increase after 1990 as a results of a constructed drainage ditch that allowed sediment to be
transported to the wetland. d Schematic diagramof predominant sediment sources and the variations
in sediment size and source with runoff magnitude (adapted from Miller et al. 2013 )
source contributions, combined with observed changes in Cu and Zn within the
cores, suggested that sediment export from upper to lower catchment areas was lim-
ited until the early 1990s, in part because the lower parts of the watershed were hydro-
logically disconnected from the upper catchment wetlands during low- to moderate