64
Tajikistan and Kyrgyzstan are predicted to be the countries most affected by
rainfall erosivity. The increasing trends in annual rainfall erosivity from baseline
climate up to the GCMs and the climate scenarios experienced variations in rainfall
erosivity. There is a positive change in the average annual rainfall erosivity of 5.6%
and 9.6% in the 2030s and 2070s, respectively, compared with the baseline
(1960–1990).
The BCCCSM1.1 scenarios projected both an increase and a decrease in the
mean rainfall erosivity in Kyrgyzstan (−7.8% to 6.3%), Tajikistan (−26.3% to
3.8%), Turkmenistan (−19% to 10.5%), and Uzbekistan (−17.7% to 9%) and an
increase in Kazakhstan (11.6% to 23.2%). The IPSLCM5ALR scenarios projected
a decrease in the mean rainfall erosivity in Kyrgyzstan (−14.5% to −35.5%),
Tajikistan (−8.2% to −26.2%), Turkmenistan (−7.1% to −16.7%), and Uzbekistan
(−7.7% to −28.2%) and both an increase and a decrease in Kazakhstan (−1.6% to
1.5%). The MIROC5 scenarios projected an increase in Kyrgyzstan (27.9% to
50.1%), Kazakhstan (5.3% to 27.3%), Tajikistan (34.3% to 56.3%), and Uzbekistan
(2.1% to 24.1%) and both an increase and a decrease in Turkmenistan (−4.7% to
19.6%). The MPIESMLR scenarios projected a mean rainfall erosivity increase in
Kyrgyzstan (0.9% to 27%), Kazakhstan (0.6% to 15.7%), and Turkmenistan (2.3%
to 14.3%) and both an increase and decrease in Tajikistan (−2.2% to 24.4%) and
Uzbekistan (−2.7% to 15.3%). The average values of erosion variations presented
in this study are average changes in countries, whereas within these countries, we
found both an increase and a decrease, which emphasize some spatial variabilities
of rainfall erosivity and soil erosion in Central Asia.
The aggregate average annual precipitation and erosion activity for all climate
models for all scenarios exhibit a steady growth compared with the baseline climate.
Only IPSLCM5ALR (RCP 2.6 and RCP 8.5) shows a decrease in the average erosivity for the 2030 and 2070 scenarios. Higher amounts of rainfall were the main
factor for the spatiotemporal variability in rainfall erosivity.
The spatial–temporal variation of rainfall erosivity in Kazakhstan in 1970–2017
was investigated by the model of Renard and Freimund (1994). The results revealed
that the average annual rainfall erosivity in Kazakhstan over the past 48 years was
464 MJ mm ha
−1
h
−1
year
−1
. No significant time trend was observed in the annual
rainfall erosivity. Some of the results presented here are relevant to the further study
of potential soil erosion in Kazakhstan.
The East Kazakhstan, North Kazakhstan, and Almaty regions were under a more
significant threat of rainfall erosivity than other regions. Most of the meteorological
stations observed exhibited non-significant upward trends and few downward
trends. The rainfall erosivity in Kazakhstan exhibits a tendency to increase, and the
probability of water and soil erosion caused by precipitation is continuously
increasing.
This study estimated the long-term variations in the annual rainfall erosivity in
Kazakhstan using past and future climatic data. The increasing trends in the annual
rainfall erosivity were obtained from the baseline climate up to the GCMs
(GISSE2H, HadGEM2-ES, and NorESM1M), and the climate scenarios experienced variations in rainfall erosivity. Based on the baseline climate, the average
6 Conclusions and Recommendations
Tajikistan and Kyrgyzstan are predicted to be the countries most affected by
rainfall erosivity. The increasing trends in annual rainfall erosivity from baseline
climate up to the GCMs and the climate scenarios experienced variations in rainfall
erosivity. There is a positive change in the average annual rainfall erosivity of 5.6%
and 9.6% in the 2030s and 2070s, respectively, compared with the baseline
(1960–1990).
The BCCCSM1.1 scenarios projected both an increase and a decrease in the
mean rainfall erosivity in Kyrgyzstan (−7.8% to 6.3%), Tajikistan (−26.3% to
3.8%), Turkmenistan (−19% to 10.5%), and Uzbekistan (−17.7% to 9%) and an
increase in Kazakhstan (11.6% to 23.2%). The IPSLCM5ALR scenarios projected
a decrease in the mean rainfall erosivity in Kyrgyzstan (−14.5% to −35.5%),
Tajikistan (−8.2% to −26.2%), Turkmenistan (−7.1% to −16.7%), and Uzbekistan
(−7.7% to −28.2%) and both an increase and a decrease in Kazakhstan (−1.6% to
1.5%). The MIROC5 scenarios projected an increase in Kyrgyzstan (27.9% to
50.1%), Kazakhstan (5.3% to 27.3%), Tajikistan (34.3% to 56.3%), and Uzbekistan
(2.1% to 24.1%) and both an increase and a decrease in Turkmenistan (−4.7% to
19.6%). The MPIESMLR scenarios projected a mean rainfall erosivity increase in
Kyrgyzstan (0.9% to 27%), Kazakhstan (0.6% to 15.7%), and Turkmenistan (2.3%
to 14.3%) and both an increase and decrease in Tajikistan (−2.2% to 24.4%) and
Uzbekistan (−2.7% to 15.3%). The average values of erosion variations presented
in this study are average changes in countries, whereas within these countries, we
found both an increase and a decrease, which emphasize some spatial variabilities
of rainfall erosivity and soil erosion in Central Asia.
The aggregate average annual precipitation and erosion activity for all climate
models for all scenarios exhibit a steady growth compared with the baseline climate.
Only IPSLCM5ALR (RCP 2.6 and RCP 8.5) shows a decrease in the average erosivity for the 2030 and 2070 scenarios. Higher amounts of rainfall were the main
factor for the spatiotemporal variability in rainfall erosivity.
The spatial–temporal variation of rainfall erosivity in Kazakhstan in 1970–2017
was investigated by the model of Renard and Freimund (1994). The results revealed
that the average annual rainfall erosivity in Kazakhstan over the past 48 years was
464 MJ mm ha
−1
h
−1
year
−1
. No significant time trend was observed in the annual
rainfall erosivity. Some of the results presented here are relevant to the further study
of potential soil erosion in Kazakhstan.
The East Kazakhstan, North Kazakhstan, and Almaty regions were under a more
significant threat of rainfall erosivity than other regions. Most of the meteorological
stations observed exhibited non-significant upward trends and few downward
trends. The rainfall erosivity in Kazakhstan exhibits a tendency to increase, and the
probability of water and soil erosion caused by precipitation is continuously
increasing.
This study estimated the long-term variations in the annual rainfall erosivity in
Kazakhstan using past and future climatic data. The increasing trends in the annual
rainfall erosivity were obtained from the baseline climate up to the GCMs
(GISSE2H, HadGEM2-ES, and NorESM1M), and the climate scenarios experienced variations in rainfall erosivity. Based on the baseline climate, the average
6 Conclusions and Recommendations