Method to predict cropland ephemeral gully erosion

Evaluating ephemeral gullies with a process-based topographic index model

“…Woodward (1999) developed a physically based Ephemeral Gully Erosion Model (EGEM) in which locations of EGs and EG length were to be provided by the user. Gordon et al (2007) addressed limitations of EGEM by revising equations for flow that resulted in a Revised EGEM (REGEM) model and incorporated it as a module within the Annualized Agricultural Non-Point Source Model to add EG erosion prediction to standard sheet and rill erosion.…”

Predicting Ephemeral Gully Location and Length Using Topographic Index Models

“…The importance of EG erosion is well established (Foster, 1986;Thorne et al, 1986;Poesen et al, 1996;Nachtergaele and Poesen, 1999;Poesen et al, 2003), but only a few process-based hydrologic or erosion models have included EG subroutines: Ephemeral Gully Erosion Model (EGEM; Woodward, 1999); Revised Ephemeral Gully Erosion Model (REGEM; Gordon et al, 2007); Chemicals, Runoff, and Erosion from Agricultural Management Systems (CREAMS; Knisel, 1980); Groundwater Loading Effects of Agricultural Management Systems (GLEAMS; Knisel, 1993); Water Erosion Prediction Project (WEPP; Flanagan and Nearing, 1995); and Annualized Agricultural Nonpoint Source Model (AnnAGNPS; Bingner and Theurer, 2003). These models, however, do not predict the location of EGs, which must be input into the models.…”

Numerical modeling of erosion using an improvement of the extended finite element method

“…More refined models try to include the influence of the sediments detached from the soil (see for example (Woodward, 1999;Bonelli et al, 2006;Brivois et al, 2007)), or consider probabilistic models for the erosion factors (Sidorchuk, 2005), however it remains unclear whether the alternatives they provide are truly required with respect to the simpler model of equation [7]. Following (Wan et al, 2004a;Knapen et al, 2007), an approximation can be used to derive the hydraulic shear stress as a function of the gradient of the hydraulic head,…”