Fingerprinting method for identification of sediment sources in a rural watershed

In this study, the fingerprinting method was used to identify sediment sources in a small rural watershed located in a mountainous region in southern Brazil. This watershed represents a typical agricultural ecosystem, in which smallhold farmers cultivate tobacco in marginal areas, with severe consequences to the natural resources. The identification of sediment sources, based on analysis of sediments transported in suspension, enables an evaluation of which areas are truly contributing to sediment production and, therefore, to make inferences about the polluting potential of these sediments. The study considered the main limitations of this method, as well as its potential in the identification of sediment sources. Through classification, it was possible to identify the relative contribution of these different sources, with fields and roads being predominant. Results showed that the contribution from these two sources varied over time and that the relative proportion of the contribution from each source varied according to management and soil cover in the fields and maintenance work performed in the roads. The average contribution from fields and roads was 64 and 36%, respectively.

sediment yield; composite fingerprinting technique; small watersheds monitoring and modeling

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