30
Our results are comparable with those of Kulikov et al. (2020), which indicate that
soil erodibility in the study site was 0.0374 t h MJ
−1
mm
−1
in mountain rangelands
of south–western Kyrgyzstan. This indicates that organic matter plays a significant
role in reducing the erodibility of soil (Amanambu et al. 2019; Gupta and
Kumar 2017).
A steeply inclined section has a high coefficient of the gradient (Fig. 4.1c). The
LS factor values vary from 0.0 to 525.8, with a mean of 4.2 and a standard deviation
of 18.8 (Table 4.1). The length and degree of slope inclination are the determining
factors in the erosion process. The high LS values of the terrain indicate higher
susceptibility to soil erosion.
The C factor was calculated using NDVI to obtain better information about the
density of the vegetation cover. It represents better spatial variability of the C factor.
The C values have a tendency to grow from the northeast to the southwest of Central
Asia. The cover management (C) factor values of the study area range from 0.005
to 0.058. The mean C factor was 0.040, with a standard deviation of 0.008
(Table 4.1). Many researchers have used NDVI to compute the cover management
factor. The spatial distribution of the C factor, which is assigned based on the NDVI,
is presented in Fig. 4.1d. The P factor values range from 0.5 to 1.0, with a mean of
0.9 and a standard deviation of 0.18 in Kyrgyzstan (Table 4.1).
4.2 Current Rate of Soil Erosion in Central Asia
The results of this work indicate that the mountainous regions of Kyrgyzstan are highly
vulnerable to soil erosion. The complex topography and vulnerability to severe semiarid weather conditions, combined with often poorly monitored pasture practices,
make this environment particularly fragile. The average rate of annual soil erosion for
the baseline period assessed for the study area varies from <0.01 to >20 t h
−1
y
−1
. The
mean soil erosion in the study area is 2.62 t h
−1
y
−1
. The annual soil loss in Central Asia
is 1013.16 × 10
6
t year
–1
. Based on the low and high values of the results, the estimated
average annual soil erosion in the study area was grouped into five classes (Tables 4.2
and 4.3). The spatial distribution of each class is presented in Fig. 4.2.
4.3 Rainfall Erosivity Analysis Under Baseline and Projected
Climate
The WorldClim data (baseline) and observation precipitation were statistically compared. A correlation coefficient of about 0.91 was observed between the baseline
and the observed average monthly precipitation. The average annual rainfall erosivity for the observation data ranges from 71.7 to 2390.3 MJ mm ha
−1
h
−1
year
−1
with
a mean of 497.8 MJ mm ha
−1
h
−1
year
−1
and standard deviation of 359 MJ mm ha
−1
4 Projected Rainfall Erosivity and Soil Erosion in Central Asia
Our results are comparable with those of Kulikov et al. (2020), which indicate that
soil erodibility in the study site was 0.0374 t h MJ
−1
mm
−1
in mountain rangelands
of south–western Kyrgyzstan. This indicates that organic matter plays a significant
role in reducing the erodibility of soil (Amanambu et al. 2019; Gupta and
Kumar 2017).
A steeply inclined section has a high coefficient of the gradient (Fig. 4.1c). The
LS factor values vary from 0.0 to 525.8, with a mean of 4.2 and a standard deviation
of 18.8 (Table 4.1). The length and degree of slope inclination are the determining
factors in the erosion process. The high LS values of the terrain indicate higher
susceptibility to soil erosion.
The C factor was calculated using NDVI to obtain better information about the
density of the vegetation cover. It represents better spatial variability of the C factor.
The C values have a tendency to grow from the northeast to the southwest of Central
Asia. The cover management (C) factor values of the study area range from 0.005
to 0.058. The mean C factor was 0.040, with a standard deviation of 0.008
(Table 4.1). Many researchers have used NDVI to compute the cover management
factor. The spatial distribution of the C factor, which is assigned based on the NDVI,
is presented in Fig. 4.1d. The P factor values range from 0.5 to 1.0, with a mean of
0.9 and a standard deviation of 0.18 in Kyrgyzstan (Table 4.1).
4.2 Current Rate of Soil Erosion in Central Asia
The results of this work indicate that the mountainous regions of Kyrgyzstan are highly
vulnerable to soil erosion. The complex topography and vulnerability to severe semiarid weather conditions, combined with often poorly monitored pasture practices,
make this environment particularly fragile. The average rate of annual soil erosion for
the baseline period assessed for the study area varies from <0.01 to >20 t h
−1
y
−1
. The
mean soil erosion in the study area is 2.62 t h
−1
y
−1
. The annual soil loss in Central Asia
is 1013.16 × 10
6
t year
–1
. Based on the low and high values of the results, the estimated
average annual soil erosion in the study area was grouped into five classes (Tables 4.2
and 4.3). The spatial distribution of each class is presented in Fig. 4.2.
4.3 Rainfall Erosivity Analysis Under Baseline and Projected
Climate
The WorldClim data (baseline) and observation precipitation were statistically compared. A correlation coefficient of about 0.91 was observed between the baseline
and the observed average monthly precipitation. The average annual rainfall erosivity for the observation data ranges from 71.7 to 2390.3 MJ mm ha
−1
h
−1
year
−1
with
a mean of 497.8 MJ mm ha
−1
h
−1
year
−1
and standard deviation of 359 MJ mm ha
−1
4 Projected Rainfall Erosivity and Soil Erosion in Central Asia