Modeling furrow irrigation-induced erosion using a process-based approach

Furrow irrigation is one of the most common irrigation methods across the globe but also contributes to significant sediment discharge to downstream surface waters. Accurate furrow erosion prediction tools are needed but no modeling approach has been widely adopted. In this study, we compare two process-base modeling approaches for furrow irrigation erosion: 1) the transport capacity Tc concept and 2) a semi-empirical approach in which furrow erodibility exponential decreases with length. A dynamic soil erodibility modeling approach whereby soil erodibility is allowed to decrease as erosion progressed was also tested to improve erosion prediction performance.  Performance assessment demonstrated the strength of the Tc model when combined with the dynamic soil erodibility approach. The study also highlighted weaknesses of the Tc model in accounting for observed deposition patterns. The proposed process-based furrow erosion functions can be directly coupled with furrow flow routing models or other hillslope erosion models.