UNCERTAINTIES OF THE Cs-137 TECHNIQUE FOR VALIDATION OF SOIL REDISTRIBUTION MODELLING IN A SEMIARID MESO-SCALE WATERSHED

作者：Medeiros Pedro H A^*; de Araujo Jose Carlos; Andrello Avacir C

来源：Engenharia Agricola, 2014, 34(2): 222-235.

• Cs-137
• soil redistribution
• sediment modelling
• semiarid

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 Cs-137 technique was used to assess the WASA-SED model performance at the Bengue watershed (933 km(2)), in the Brazilian semiarid. Qualitatively, good agreement was found among the Cs-137 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 Cs-137 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.

• 出版日期2014-4