Dissertations and Theses

RILL ERODIBILITY AND CRITICAL SHEAR STRESS OF LATOSOLS WITH DIFFERENT IRON OXIDES

Author: Grenda Hingrid Alcantara

Keywords: rill erosion, WEEP, sediment, flow regime

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Summary

- In erosion prediction models, in the case of the Water Erosion Prediction Project (WEPP), it is necessary to determine the soil properties related to its erosion resistance. Thus, the objective of this work was to determine the RILL erodibility (Kr) and critical shear stress (c) in Oxisols with different levels of iron oxides in the northeastern region of the State of São Paulo. Furrow erosion was evaluated with simulated rain of 65 mm h-1 mean intensity applied for 65 minutes, as well as additional water flows (11, 39 and 64 L min-1 ) in six preformed grooves in each Latosol, 9.0 m in length, 0.10 m in depth and 0.25 m in width in each soil. The Kr values for the Oxisols were 0.0094 s m-1 to 0.0035 s m-1 . The most kaolinitic Oxisols presented the highest values of Kr. The values of c were 2.915 N m-2 to 2.514 N m-2 . The Ct/(Ct + Gb) ratio explained 90% of the variations in erodibility in grooves and 94% of those observed for critical shear stress in the four Oxisols.