23
E
ª
¬
º
¼
sin / .
sin
.
.
T
T
0 0896
3
056
0 8
(3.13)
S
t
­
®
¯
10 8
003
9
16 8
05
9
. sin
. ,
%
. sin
. ,
%
T
T
T
T
(3.14)
where θ is the slope angle.
For very steep slopes which are not correctly covered by the S factor, Schmidt
et al. (2019) developed the S factor equation for the alpine environment (Eq. 3.15):
S
s
s
alpine
0 0005
0 7956 0 4418
2
.
.
.
(3.15)
where s is the slope steepness in percent.
In this work, the LS factor was implemented in the System for Automated
Geoscientific Analyses (SAGA) 7.1.1 software. The result of the LS values was
mapped in ArcGIS 10.2.
3.2.4 Cover Management (C) Factor
The C factor compares the loss of soil from an exact type of vegetation cover. A
widely used approach to the C factor estimation is based on the use of remote sensing data (Borrelli et al. 2018; Kulikov et al. 2016; Panagos et al. 2015a; Schmidt
et  al. 2018). The C factor was assessed using the MODIS NDVI (June–August
2017). MODIS 16-days indicates NDVI 250-m resolution, obtained from the
National Aeronautics and Space Administration (NASA). NDVI is described in Eq.
(3.16) (Tucker 1978).
NDVI
NIR Red
NIR Red
(3.16)
where Red is the visible red, and NIR is the near-infrared spectral reflectance measurements. The values of NDVI range from −1 to 1. Equation (3.17) was used to
produce the C factor (Almagro et al. 2019). The C factor was proposed by Durigon
et al. (2014) and adapted by Colman (2018).
C
NDVI
§
©
¨
·
¹
¸
0 1
1
2
.
(3.17)
3.2 RUSLE Model and Its Factors