Assessment of areal water and tillage erosion using magnetic susceptibility: the approach and its application in Moroccan watershed

Estimation of Soil Losses by the Improved Tillage Homogenization Model and Rusle Model

“…Mass-specific low-frequency magnetic susceptibility (χ lf ) is expressed in unit of 10 -8 m 3 kg -1 and defined by the following equation 1: Tillage homogenization model is a methodology proposed by Royall (2001) and improved by Bouhlassa and Bouhsane (2019) for estimating erosion depth using magnetic susceptibility of soils. This model allows predicting the mean values of magnetic parameters of the ploughing layers after erosion of the surface soil layer (Bouhlassa and Bouhsane, 2019). To run this model, a reference profile of unperturbed and non-eroded soil is mandatory (Royall, 2004;Landgraf and Royall, 2006;Jordanova et al, 2014).…”

“…To run this model, a reference profile of unperturbed and non-eroded soil is mandatory (Royall, 2004;Landgraf and Royall, 2006;Jordanova et al, 2014). The T-H model is based on the supposition that tillage operations cause homogenization of the uppermost 20 cm, and therefore magnetic signal should be uniform within this layer (Jordanova et al, 2014;Bouhlassa and Bouhsane, 2019). After an erosion process, a deeper soil layer are involved in ploughed horizon with a decrease of the initial value of magnetic susceptibility.…”

“…Empirical models such as RUSLE (Revised Universal Soil Loss Equation) based on GIS (Geographic Information System) data have been used largely (Renard et al, 1997;Wijesundara et al, 2018); but it depends on numerous input parameters that are not available at all spatial and temporal scales, and leads often to underestimated or overestimated results (Royall, 2004). Compared with radionuclide methods, the magnetic susceptibility technique has been proven to be the fast and non-destructive method to estimate soil erosion (Sadiki et al, 2009;Bouhlassa and Bouhsane, 2019;Liu et al, 2015;Yu et al, 2017;. The study carried by Bouhlassa and Bouhsane (2019) establishes a methodology and specifies conditions that improves the use of magnetic susceptibility in the estimation of erosion or redeposition in the watershed.…”

“…Compared with radionuclide methods, the magnetic susceptibility technique has been proven to be the fast and non-destructive method to estimate soil erosion (Sadiki et al, 2009;Bouhlassa and Bouhsane, 2019;Liu et al, 2015;Yu et al, 2017;. The study carried by Bouhlassa and Bouhsane (2019) establishes a methodology and specifies conditions that improves the use of magnetic susceptibility in the estimation of erosion or redeposition in the watershed. Tillage homogenization (T-H) model based on magnetic susceptibility parameter has been proposed by Royall (2001) to estimate soil loss in cultivated lands.…”

“…This model permits to estimate cumulative soil loss at a point based on easily, cheaply, and rapidly acquired measurement of the top soil magnetism (Royall , 2004). T-H model was used by several researchers, such as Jordanova et al (2014) and Bouhlassa and Bouhsane (2019). The objective of this study is to evaluate soil erosion using two erosion models in the Mezguida watershed, then compare these two models.…”