The Current State of Predicting Furrow Irrigation Erosion

Authors: Bjorneberg, David - Dave; Strelkoff, Theodor; Clemmens, Albert; Lee, Joon-Hee

Submitted to: Decennial National Irrigation Symposium
Publication Type: Proceedings
Publication Acceptance Date: 8/20/2010
Publication Date: 12/5/2010
Citation: Bjorneberg, D.L., Strelkoff, T., Clemmens, A.J., Lee, J. 2010. The Current State of Predicting Furrow Irrigation Erosion. In: 5th National Decennial Irrigation Conference, December 5-8, 2010, Phoenix, Arizona. p.1-11.

Interpretive Summary: There continues to be a need to predict furrow irrigation erosion to estimate on- and off-site impacts of irrigation management. The objective of this paper is to review the current state of furrow erosion prediction technology considering four models: SISL, WEPP, WinSRFR and APEX. SISL is an empirical model for predicting annual soil loss from furrow irrigated fields. SISL could potentially be a useful model if a new method was developed to calculate base soil loss for areas other than southern Idaho where it was developed. The WEPP model uses physically-based equations to predict erosion in irrigation furrows, which are assumed to be the same as rills. Primary difficulties with the WEPP model are defining erodibility parameters for furrow irrigation and over-prediction of transport capacity. WinSRFR provides detailed evaluation of furrow hydraulics and sediment detachment, transport and deposition in an individual furrow during a single irrigation event using similar equations as WEPP. Initial evaluations of WinSRFR are promising and development continues to fully simulate the mix of aggregate sizes found in furrow soil and furrow flow. The APEX model uses empirical relationships to predict soil loss from small watersheds. Preliminary evaluation of the APEX model indicated reasonable correlation with measured soil loss in a 170 ha irrigated watershed. All of these methods require further development and/or evaluation before they can be widely applied to furrow irrigated land. In selecting a predictive tool, it should be noted that an empirical equation may be as good as a physically based equation if we cannot quantify the parameters for the physically based equation.

Technical Abstract: There continues to be a need to predict furrow irrigation erosion to estimate on- and off-site impacts of irrigation management. The objective of this paper is to review the current state of furrow erosion prediction technology considering four models: SISL, WEPP, WinSRFR and APEX. SISL is an empirical model for predicting annual soil loss from furrow irrigated fields. SISL could potentially be a useful model if a new method was developed to calculate base soil loss for areas other than southern Idaho where it was developed. The WEPP model uses physically-based equations to predict erosion in irrigation furrows, which are assumed to be the same as rills. Primary difficulties with the WEPP model are defining erodibility parameters for furrow irrigation and over-prediction of transport capacity. WinSRFR provides detailed evaluation of furrow hydraulics and sediment detachment, transport and deposition in an individual furrow during a single irrigation event using similar equations as WEPP. Initial evaluations of WinSRFR are promising and development continues to fully simulate the mix of aggregate sizes found in furrow soil and furrow flow. The APEX model uses empirical relationships to predict soil loss from small watersheds. Preliminary evaluation of the APEX model indicated reasonable correlation with measured soil loss in a 170 ha irrigated watershed. All of these methods require further development and/or evaluation before they can be widely applied to furrow irrigated land. In selecting a predictive tool, it should be noted that an empirical equation may be as good as a physically based equation if we cannot quantify the parameters for the physically based equation.