Page 152 - Çevre Şehir ve İklim Dergisi İngilizce - Özel Sayı

Determination of Erosion Statistics by Land Use Type at National Scale With the
Dynamic Erosion Model and Monitoring System (Demms)

As a result of the regression analyses made for the K factor and statistical
assessments, it was determined that the most suitable equation for the current
data set was Torri et al., (1997) Eq. (5). The soil erodibility, which was taken
from the equation, was used in creating the K map (Figure 3c).
K =0.0293(0.65−DG+0.24DG2) × exp{−0.0021[]−0.00037[]2)–(4.02xC)+ (1.72xC2)} (5)
T
K : K: represents soil erodibility (tons ha-1 ha MJ-1 s mm-1) and Dg:
represents average T geometric particle diameter (mm).
Eq. (5) is the experimental calculation technique developed by Torri et al.
(1997), and soil particle size distribution, organic matter (OM, %) and clay (C,
%) contents are the independent variables of the equation Eq. (5). Average
geometric particle diameter is determined in detail from size distribution curves
or from three main particles (clay, silt and sand) with the soil texture analysis (KT).
C factor was determined by assigning the values determined by Panagos
et al. (2015) to 44 land cover classes in CORINE 2018. The deficiencies
and differences occurring in C values were corrected by using Forest Land
Management Maps, and proper C values were determined and used (Table 1).
The Land Cover and Use map was created by using the determined C values
(Figure 3b).
DEMMS topographic factor was interactively calculated by using land
surface drainage network distribution and by taking into consideration the
flow direction and intensity, depending on the rainfall intensity, in addition to
slope length and steepness, and the LS factor map (Figure 3d) was created
(Moore and Bruch 1986a, b; Ogawa et al., 1997) Fig. (6).
(6)

Here, χ rainage network was taken by DEM by using ArcGIS 10.2 (Lee, 2004,
n means cell size and is the sloop steepness in θ units). DEM (10x10), used in
the study, was provided by the General Directorate for Mapping (Table1).
P values show variety between 0 and 1 depending on the used erosion
control method; here, 0 value displays the decrease of erosion with proper
structures, and 1 value displays the practices to decrease erosion were a few
or did not exist (Kouli et al., 2009). Since the practices to prevent soil erosion
were done for many years in our country, but there was not any data created
on this subject, P value was added to DEMMS in order to represent 1.

139
Special Issue / 2024