Calibration of RWEQ in a patchy landscape; a first step towards a regional scale wind erosion model

Abstract

a b s t r a c tDespite the fact that wind erosion seriously affects the sustainable use of land in a large part of the world, validated wind erosion model that predicts windblown mass transport on a regional scale is lacking. The objectives of this research were to modify revised wind erosion equation (RWEQ) to estimate soil loss at a field scale in a way that it could operate at a regional scale, to calibrate the model using ground data collected from a field scale representing different land uses in Khanasser valley, Syria, and to estimate the total sediment fluxes (kg m À1 ) and soil losses (kg m À2 ) for farming fields.We implemented a modified version of RWEQ that represents wind erosion as a transient process, using time steps of 6 h. Beside this a number of adaptations including estimation of mass flux over the field boundaries, and the routing of sediment have been done. Originally, RWEQ was created and calibrated for application at the scale in USA. Due to the adaptations imparted to the original RWEQ and the different environmental condition in Syria of application areas, an intensive calibration process was required before applying the model to estimate the net soil loss from the experimental fields.The results of this test showed that the modified version of RWEQ provided acceptable predictions for the average mass flux from the measurement plot with a linear regression coefficient of R 2 of 0.57 and 0.83 for the (d) test for the 20 wind events at the six tested plots.

A New Assessment of Soil Loss Due to Wind Erosion in European Agricultural Soils Using a Quantitative Spatially Distributed Modelling Approach

“…In this study, the RWEQ model was selected because it has proven to be an effective tool (Buschiazzo & Zobeck, ; Youssef et al, ), with a straightforward modelling scheme and only a limited amount of input data. The first attempt to up‐scale RWEQ was carried out in Texas by Zobeck et al (), where the RWEQ software was employed to predict the soil loss for a number of representative fields.…”

“…The equation is relatively simple and requires a limited amount of input data, which makes it suitable for upscaling (Zobeck et al, ; Youssef et al, ; Guo et al, ). Wind is the basic driving force in the model.…”

The effect of vegetation patterns on wind-blown mass transport at the regional scale: A wind tunnel experiment

“…Furthermore, erosion that occurs in one land unit affects the units located downwind. Todd et al (2004), Fryrear et al (1998) and Youssef et al (2012) studied the effect on the maximum sediment transport and reported a gradual increase in the mass flux from bare land downwind from a non-erodible border. Therefore, to understand the effect of vegetation at the regional scale, it is vital to generate data representing processes taking place along the entire land unit and at transitions between land units.…”

Estimation of regional differences in wind erosion sensitivity in Hungary

“…In the study of Shao and Leslie (1997) measured wind transport data from a one-week survey, were scaled up to the continental scale of Australia by GIS methods, resulting in estimates that were generally problematic, because of the spatial validity of the data. By testing the calibration of RWEQ on Syrian study sites up to 150 ha in size, it was possible to acquire regional-scale results of good quality (Buschiazzo et al, 1999;Fryrear et al, 1998;Youssef et al;. Nevertheless, the plot-sized models have intense data requirements that are difficult to meet even on the local scale.…”