29
erosivity for the baseline period ranges from 41 MJ mm ha
−1
h
−1
year
−1
to 4510 MJ
mm ha
−1
h
−1
year
−1
, in the west and southeast, respectively (Fig. 4.1a).
Figure 4.1b and Table 4.1 demonstrate that the erodibility factor in the study area
varies from 0.00 to 0.050 t h MJ
−1
mm
−1
. The mean erodibility was 0.020 t h MJ
−1
mm
−1
with a standard deviation of 0.00 t h MJ
−1
mm
−1
. According to the United
States Department of Agriculture (USDA), the values range from 0.02 t h MJ
−1
mm
−1
for the least erodible soils to 0.64 t h MJ
−1
mm
−1
for the most erodible ones.
1
1 https://www.nrcs.usda.gov/wps/PA_NRCSConsumption/download?cid=stelprdb1262856&ext=
pdf
Table 4.1 The statistics related to RUSLE equation factors in Central Asian countries
Factors
Countries
Min
Max
Mean
STD
R
Kazakhstan
82.8
2915.5
370.0
229.3
Kyrgyzstan
144.2
4409.0
870.0
566.9
Tajikistan
41.1
4509.5
1444.1
1027.6
Turkmenistan
78.9
1366.1
189.9
117.0
Uzbekistan
77.6
3630.3
285.0
381.4
Central Asia
41.6
4509.5
401.5
405.0
K
Kazakhstan
0.000
0.052
0.020
0.003
Kyrgyzstan
0.000
0.041
0.020
0.002
Tajikistan
0.018
0.038
0.020
0.001
Turkmenistan
0.000
0.024
0.017
0.001
Uzbekistan
0.000
0.021
0.019
0.005
Central Asia
0.000
0.050
0.020
0.000
LS
Kazakhstan
0.0
496.5
1.5
8.9
Kyrgyzstan
0.0
487.0
29.3
44.5
Tajikistan
0.0
525.8
37.7
53.5
Turkmenistan
0.0
372.1
1.0
5.5
Uzbekistan
0.0
444.7
2.7
14.0
Central Asia
0.0
525.8
4.2
18.8
C
Kazakhstan
0.005
0.058
0.035
0.008
Kyrgyzstan
0.006
0.055
0.031
0.011
Tajikistan
0.009
0.057
0.040
0.009
Turkmenistan
0.008
0.058
0.043
0.004
Uzbekistan
0.006
0.058
0.041
0.006
Central Asia
0.005
0.058
0.040
0.008
P
Kazakhstan
0.50
1.00
0.90
0.18
Kyrgyzstan
0.50
1.00
0.89
0.19
Tajikistan
0.50
1.00
0.90
0.19
Turkmenistan
0.50
1.00
0.93
0.15
Uzbekistan
0.50
1.00
0.89
0.19
Central Asia
0.50
1.00
0.90
0.18
Note: The unit for the R factor is MJ mm ha
−1 h
−1 year
−1 , and the unit for the K factor is t h MJ
−1
mm
−1 . Other factors are dimensionless
4.1 RUSLE Model Factors
erosivity for the baseline period ranges from 41 MJ mm ha
−1
h
−1
year
−1
to 4510 MJ
mm ha
−1
h
−1
year
−1
, in the west and southeast, respectively (Fig. 4.1a).
Figure 4.1b and Table 4.1 demonstrate that the erodibility factor in the study area
varies from 0.00 to 0.050 t h MJ
−1
mm
−1
. The mean erodibility was 0.020 t h MJ
−1
mm
−1
with a standard deviation of 0.00 t h MJ
−1
mm
−1
. According to the United
States Department of Agriculture (USDA), the values range from 0.02 t h MJ
−1
mm
−1
for the least erodible soils to 0.64 t h MJ
−1
mm
−1
for the most erodible ones.
1
1 https://www.nrcs.usda.gov/wps/PA_NRCSConsumption/download?cid=stelprdb1262856&ext=
Table 4.1 The statistics related to RUSLE equation factors in Central Asian countries
Factors
Countries
Min
Max
Mean
STD
R
Kazakhstan
82.8
2915.5
370.0
229.3
Kyrgyzstan
144.2
4409.0
870.0
566.9
Tajikistan
41.1
4509.5
1444.1
1027.6
Turkmenistan
78.9
1366.1
189.9
117.0
Uzbekistan
77.6
3630.3
285.0
381.4
Central Asia
41.6
4509.5
401.5
405.0
K
Kazakhstan
0.000
0.052
0.020
0.003
Kyrgyzstan
0.000
0.041
0.020
0.002
Tajikistan
0.018
0.038
0.020
0.001
Turkmenistan
0.000
0.024
0.017
0.001
Uzbekistan
0.000
0.021
0.019
0.005
Central Asia
0.000
0.050
0.020
0.000
LS
Kazakhstan
0.0
496.5
1.5
8.9
Kyrgyzstan
0.0
487.0
29.3
44.5
Tajikistan
0.0
525.8
37.7
53.5
Turkmenistan
0.0
372.1
1.0
5.5
Uzbekistan
0.0
444.7
2.7
14.0
Central Asia
0.0
525.8
4.2
18.8
C
Kazakhstan
0.005
0.058
0.035
0.008
Kyrgyzstan
0.006
0.055
0.031
0.011
Tajikistan
0.009
0.057
0.040
0.009
Turkmenistan
0.008
0.058
0.043
0.004
Uzbekistan
0.006
0.058
0.041
0.006
Central Asia
0.005
0.058
0.040
0.008
P
Kazakhstan
0.50
1.00
0.90
0.18
Kyrgyzstan
0.50
1.00
0.89
0.19
Tajikistan
0.50
1.00
0.90
0.19
Turkmenistan
0.50
1.00
0.93
0.15
Uzbekistan
0.50
1.00
0.89
0.19
Central Asia
0.50
1.00
0.90
0.18
Note: The unit for the R factor is MJ mm ha
−1 h
−1 year
−1 , and the unit for the K factor is t h MJ
−1
mm
−1 . Other factors are dimensionless
4.1 RUSLE Model Factors