Can reservoir bottom sediments be used in the estimation of long-term catchment sediment budgets?

In the last 30 years, major progress has been made in the development of methods for establishing catchment sediment budgets. Reservoir bottom sediments are important because they provide valuable medium- to long-term archives of catchment sediment yield. Dating techniques, such as ¹³⁷Cs and ²¹⁰Pb further provide the opportunity to subdivide this stratigraphic record into shorter time periods. Recently, sediment-fingerprinting approaches have been applied to dated sediment cores to gain insight into changing patterns of sediment supply. In this study, a land-use-based sediment fingerprinting study was undertaken in the 4.9 km² Crombie Reservoir catchment in northeast Scotland to infer historical changes in sediment supply over the past 135 years. The unmixing model employed, features a novel enrichment-inclusive subroutine. Fingerprinting results show a rise in agricultural sediment production from effectively zero in 1890 to >80% in 1980, with patterns broadly correlating to known land-use changes with a climatic overprint.