45
frontal zones, which significantly affect the development of cyclonic activity in
Central Asia. The mountain barrier significantly reduces the amount of precipitation
brought by the West, in particular by southwestern (Mediterranean) cyclones to
Central Asia (Issanova and Abuduwaili 2017).
As stated by Amanambu et al. (2019), erosion is influenced by the changes in
precipitation patterns and quantities due to climate change. Studies in the Eurasian
continent predicted a significant increase or decrease in erosivity for the future climate. For example, Panagos et al. (2017a) found that 81% of the territory in Europe
is projected to have an increase in rainfall erosivity, and it is projected that by 2050,
there will be a 19% decrease in rainfall erosivity (HadGEM2, RCP 4.5 scenario).
Likewise, however, our study predicts some spatial variability in erosivity for
Central Asia concerning the anthropogenic influence on the amount of precipitation
based on different GCMs.
Besides, the powerful influence of climate change on soil erosion is another
essential factor that is uncertain; however, it may depend on the interacting effects
of the associated factors. In the climate change-based soil erosivity predictions, it
can be observed that the average soil loss, resulting from the RUSLE model within
the ensemble combinations, yet show some disparities. However, future soil erosion
rates are expected to increase due to increased precipitation and rainfall erosivity.
This has been confirmed in other prediction studies (Amanambu et al. 2019; Gupta
and Kumar 2017; Litschert et al. 2014; Plangoen et al. 2013), which demonstrate
that an increase in precipitation and intensity will significantly impact soil erosion rates.
Small percent variations are usually expected in developed areas, which generally have lower hills of slope and height. The variability of our results shows the
disagreements in scenarios, periods, and climate models but may also show persistent uncertainty in our models. The WorldClim precipitation data were used together
with equations based on the annual precipitation to calculate precipitation erosion
rates. The number of weather stations in the Central Asian region is limited, and the
resolution of spatial data on rainfall is low. Besides, this approach does not cover the
distribution of heavy rains, which are known to have a significant effect on soil erosion. The product of the total energy of the storm and maximum intensity of the
storm mainly determine the potential of a 30-min rainfall to cause erosion. There is
no detailed rainfall data at sub-hourly intervals for Central Asia.
The preservation of fertile soils by agricultural lands, pastures, and forests is the
primary condition for the sustainable development of humanity. The possible
increase in rainfall erosivity in Tajikistan and Kyrgyzstan may affect a significant
part of the agricultural production in Central Asia due to increased soil loss and
reduced soil fertility and water availability. Conversely, a reduction in the rainfall
erosivity over Turkmenistan and western Uzbekistan can strengthen the trend of
agricultural development in these areas. However, climate change can significantly
affect the land cover, which can balance or reinforce some erosion trends. To predict
future soil erosion trends, these feedbacks between precipitation and land cover
should be evaluated.
4.6 Rainfall Erosivity and Soil Erosion at the National Level
frontal zones, which significantly affect the development of cyclonic activity in
Central Asia. The mountain barrier significantly reduces the amount of precipitation
brought by the West, in particular by southwestern (Mediterranean) cyclones to
Central Asia (Issanova and Abuduwaili 2017).
As stated by Amanambu et al. (2019), erosion is influenced by the changes in
precipitation patterns and quantities due to climate change. Studies in the Eurasian
continent predicted a significant increase or decrease in erosivity for the future climate. For example, Panagos et al. (2017a) found that 81% of the territory in Europe
is projected to have an increase in rainfall erosivity, and it is projected that by 2050,
there will be a 19% decrease in rainfall erosivity (HadGEM2, RCP 4.5 scenario).
Likewise, however, our study predicts some spatial variability in erosivity for
Central Asia concerning the anthropogenic influence on the amount of precipitation
based on different GCMs.
Besides, the powerful influence of climate change on soil erosion is another
essential factor that is uncertain; however, it may depend on the interacting effects
of the associated factors. In the climate change-based soil erosivity predictions, it
can be observed that the average soil loss, resulting from the RUSLE model within
the ensemble combinations, yet show some disparities. However, future soil erosion
rates are expected to increase due to increased precipitation and rainfall erosivity.
This has been confirmed in other prediction studies (Amanambu et al. 2019; Gupta
and Kumar 2017; Litschert et al. 2014; Plangoen et al. 2013), which demonstrate
that an increase in precipitation and intensity will significantly impact soil erosion rates.
Small percent variations are usually expected in developed areas, which generally have lower hills of slope and height. The variability of our results shows the
disagreements in scenarios, periods, and climate models but may also show persistent uncertainty in our models. The WorldClim precipitation data were used together
with equations based on the annual precipitation to calculate precipitation erosion
rates. The number of weather stations in the Central Asian region is limited, and the
resolution of spatial data on rainfall is low. Besides, this approach does not cover the
distribution of heavy rains, which are known to have a significant effect on soil erosion. The product of the total energy of the storm and maximum intensity of the
storm mainly determine the potential of a 30-min rainfall to cause erosion. There is
no detailed rainfall data at sub-hourly intervals for Central Asia.
The preservation of fertile soils by agricultural lands, pastures, and forests is the
primary condition for the sustainable development of humanity. The possible
increase in rainfall erosivity in Tajikistan and Kyrgyzstan may affect a significant
part of the agricultural production in Central Asia due to increased soil loss and
reduced soil fertility and water availability. Conversely, a reduction in the rainfall
erosivity over Turkmenistan and western Uzbekistan can strengthen the trend of
agricultural development in these areas. However, climate change can significantly
affect the land cover, which can balance or reinforce some erosion trends. To predict
future soil erosion trends, these feedbacks between precipitation and land cover
should be evaluated.
4.6 Rainfall Erosivity and Soil Erosion at the National Level