Process-based soil erodibility estimation for empirical water erosion models

ABSTRACT

Functional relationships between soil erodibility equations of empirically-based revised universal soil loss equation and process-based water erosion prediction project models were investigated using new datasets from rainfall simulation experiments to overcome conceptual differences of models in estimating soil erodibility. Erodibility potentials of two different soils were quantified for three different initial soil moisture conditions, and relations between the process-based erodibility, partitioned as interrill erodibility, rill erodibility and critical shear stress, and empirically-based erodibility were examined. A process-based soil erodibility assessment within the universal soil loss equation was attempted. Statistically significant differences are found when considering the effects of surface hydrologic conditions on soil erodibility. Process-based soil erodibility estimates under dry conditions were found to be comparable with original water erosion prediction project datasets. The results showed that procedure could be useful for tapping into the large number of datasets available and building the next generation of process-based erosion models.

Keywords:

• Critical shear stress
• dispersion
• erosion
• interrill and rill erodibility
• revised universal soil loss equation
• water–sediment interface interactions

Acknowledgements

The authors would like to acknowledge the scientific guidance of Dr K. Nouwakpo and the support of Dr Q. Wu. Also a special thanks to B. Hofmann and all the staff at the USDA-ARS National Soil Erosion Research Laboratory for their kind technical assistance.

Additional information

Funding

This work was conducted with funding provided by the Turkey Higher Education Council [grant YOK/PostDoc/2547-39/19508].