Uncertainties of the 137Cs technique for validation of soil redistribution modelling in a semiarid meso-scale watershed

Engenharia Agrícola

Pedro H. A. Medeiros²  José Carlos De Araújo¹  Avacir C. Andrello¹ 

[1] ,Instituto Federal de Educação, Ciência e Tecnologia do CearáMaracanaú CE

关键词: 137Cs;    soil redistribution;    sediment modelling;    semiarid;    137Cs;    redistribuição de solo;    modelagem sedimentológica;    semiárido;   

DOI  :  10.1590/S0100-69162014000200004

来源: SciELO

【 摘 要 】

Scarcity of long-term series of sediment-related variables has led watershed managers to apply mathematical models to simulate sediment fluxes. Due to the high efforts for installation and maintenance of sedimentological gauges, tracers have been pointed out as an alternative to validate soil redistribution modelling. In this study, the 137Cs technique was used to assess the WASA-SED model performance at the Benguê watershed (933 km²), in the Brazilian semiarid. Qualitatively, good agreement was found among the 137Cs technique and the WASA-SED model results. Nonetheless, quantitatively great differences, up to two orders of magnitude, were found between the two methods. Among the uncertainties inherent to the 137Cs technique, definition of the reference inventory seems to be a major source of imprecision. In addition, estimations of water and sediment fluxes with mathematical models usually also present high uncertainty, contributing to the quantitative differences of the soil redistribution estimates with the two methods.

【 授权许可】

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