Process-based modeling of furrow irrigation erosion

Authors: Nouwakpo, Sayjro; Bjorneberg, David; King, Bradley

Submitted to: Journal of Irrigation and Drainage Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/26/2025
Publication Date: 8/1/2025
Citation: Nouwakpo, S.K., Bjorneberg, D.L., King, B.A. 2025. Process-based modeling of furrow irrigation erosion. Journal of Irrigation and Drainage Engineering. 151(4):0405020-1-04025020-9. https://doi.org/10.1061/JIDEDH.IRENG-10540.
DOI: https://doi.org/10.1061/JIDEDH.IRENG-10540

Interpretive Summary: This study proposes a process-based modeling approach for furrow irrigation-induced soil erosion. The paper contrasts the traditional transport capacity approach with a semi-empirical model that relates erodibility to furrow length. Results suggest that the transport capacity model performed well when furrow erodibility was allowed to decrease with time as erosion progressed. The semi-empirical approach performed reasonably well and offers a simplified method for computing furrow erosion without the need to calculate transport capacity values. The developed approach provides a foundation for process-based modeling of furrow irrigation-induced erosion that can be incorporated into existing surface irrigation flow routing models or other hillslope soil erosion prediction tools.

Technical Abstract: Furrow irrigation represents 18% of all irrigated lands in the United States but may disproportionately contribute to water quality degradation. Accurate furrow erosion models are needed but no satisfactory model exists. In this paper, we propose a process-based modeling framework by comparing two approaches: 1) the transport capacity (Tc) concept and 2) a semi-empirical approach in which furrow erodibility exponential decreases with length. Furrow erodibility k' was either assumed constant or exponentially decayed with time (dynamic erodibility). The best performance was obtained with the Tc approach when the dynamic k' was used (R2 = 0.68, Nash-Sutcliffe Efficiency - NSE = 0.61 and Percent Bias - PBIAS = -14.87% on evaluation data) while the semi-empirical approach did not show any benefit of the dynamic k' (R2= 0.69, NSE = 0.65 and PBIAS = -21.93% at evaluation). The inability of the Tc model to account of deposition was found to be a key limitation of this approach. These process-based furrow erosion functions can be directly coupled with furrow flow routing models or other hillslope erosion models.