Wepp Model for Rill Erosion Estimation in a Brazilian Semiarid Watershed

Abstract

Soil erosion is a major environmental problem in many parts of the world and represents a serious problem for sustainable agriculture and the environment, with direct and indirect impacts on soil quality and fertility. This study aimed to use the Water Erosion Prediction Project (WEPP) model to estimate rill erosion and determine soil physical and hydraulic properties, which are essential to investigate its performance. To this end, an experiment was carried out in the Exu Creek watershed, in Serra Talhada, semi -arid region of Pernambuco State (Brazil), under increasing flow rates: T1: 5.87 L min-1; T2: 12.10 L min-1; T3: 20.33 L min1; and T4: 27.57 L min-1. Liquid and solid discharges were sampled for determination and characterization of hydraulic parameters in preformed rill flows. Reynolds numbers between 2,019 and 6,929 and Froude numbers below 1 found in this study attest to occurrence of erosive rills. Soil losses due to rill erosion increased as flow rates increased. Rill erodibility was 0.0011 kg N-1 s-1, and critical shear stress (tc) was 1.91 Pa, collapsing rill sidewalls and increasing local uplift, wet perimeter, and rill hydraulic radius.

The Effect of Erosion Control Practices on the Vulnerability of Soil Degradation in Oued EL Malleh Catchment using the USLE Model Integrated into GIS, Morocco

“…Several works have been applied the physicallybased models, among those, Shivhare et al [11] have been applied the SWAT model to estimate the runoff, sediment yield, and evapotranspiration in the Ganga river watershed, in India. Other studies used WEEP model to quantify the rill erosion and to evaluate the impact of hydraulic parameters of the flow on the soil properties [12], further research have been highlighted the application of PESERA model, which is useful tool to comprehend the relationship between the input and output data scale, and their impact on water erosion modelling and sediment yield [13]. However, those models need calibration and validation and require a time series of the sediment yield and rainfall runoff data [14].…”