Evaluating WEPP-predicted furrow irrigation erosion

Evaluando la Erosión de irrigación por Surcos Predicha por WEPP

Bjorneberg, D.L. (2001) Evaluating WEPP-predicted furrow irrigation erosion. pp. 673-676. In: Ascough II, J.C. and Flanagan, D.C. (eds.) Proc. Int. Symp. Soil erosion research for the 21st Century. USA-HI-Honolulu, 2001/01/03-05. ASAE, St. Joseph, MI.

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Abstract

The Water Erosion Prediction Project (WEPP) model allows users to predict furrow irrigation erosion.
However, an initial model evaluation showed that 1) WEPP default erodibility values had to be reduced for
simulating furrow irrigation erosion and 2) the WEPP model overpredicted sediment transport capacity.
Therefore, the purpose of this study was to investigate the applicability of the governing equations used in the
WEPP model to calculate sediment detachment and transport. Sediment detachment data were collected from
53 irrigation furrows, 9 m long, on a Portneuf silt loam with flow rates varying from 2 to 50 L min-1 among
furrows. Hydraulic shear measured in irrigation furrows varied from 0.4 to 1.7 Pa, which is less than the 2.6 to
8.8 Pa shear measured during WEPP rainfall simulation on the same soil. The linear relationship between shear
and detachment rate used by the WEPP model may be appropriate for predicting both rainfall and furrow
irrigation erosion as long as separate erodibility values are identified for furrow irrigation. A power function
relating shear and detachment rate may allow one relationship to be used for both the low shear conditions in
irrigation furrows and the high shear conditions in rills during intense rain storms. Although transport capacity
could not be thoroughly evaluated with this data set, sediment detachment seemed to be limited by factors other
than transport capacity,. Additional model evaluation is needed with data from other soils before changes to the
model can be recommended or the model can be implemented for predicting furrow irrigation erosion.

Item Type:	Conference or Workshop Item (Paper)
NWISRL Publication Number:	1031
Subjects:	Irrigation > Furrow irrigation > Erosion Soil > Erosion Mass Import - autoclassified (may be erroneous)
Depositing User:	Users 6 not found.
Date Deposited:	20 Nov 2010 21:56
Last Modified:	14 Nov 2016 18:54
Item ID:	888
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/888