Fingerprinting the sources of water-mobilized sediment threatening agricultural and water resource sustainability: Progress, challenges and prospects in China

Sediment source fingerprinting apportions the sources of sediment produced by water erosion by linking sampled sediment mixtures and landscape source materials using diagnostic and conservative fingerprints. Using this approach, the nature and location of active sediment sources across the catchment can be elucidated, generating information which is a key prerequisite for the design and implementation of catchment management strategies. The science of sediment source fingerprinting continues to attract much research globally, but to date, there have been relatively few fingerprinting studies in China. Here, there remain major challenges for the fingerprinting approach arising from the uniqueness of Chinese landscapes, including for instance, the complex land use configuration with highly fragmented or mosaic patches and the highly dynamic land use conversion rates, generating a need to test the physical basis for the discriminatory power and environmental behavior of bothtraditional and novel tracers. Future research is needed to investigate the applicability of tracer properties in different physiographic settings and to evaluate the potential strategic utility of the approach for supporting the improved management of soil and water sustainability. Here, the strategic availability of independent observation data for different components of catchment sediment budgets and well-maintained research infrastructure for plots, micro-catchments and drainage basins provides immediate opportunity for testing the approach and refining procedures. Such detailed testing across scales would be invaluable for promoting sediment