Future changes in drought over Central Asia under CMIP6 forcing scenarios

Abstract

Study region: Central Asia.Study focus: The possible future changes in meteorological, hydrological and agricultural drought in Central Asia are analyzed based on the multi-model projections from phase 6 of the Coupled Model Intercomparison Project (CMIP6). The changes in hydroclimate variables and drought events are examined to reveal the responses to different emissions pathway by comparing the historical period (1995–2014) and future period (2081–2100).New hydrological insights for the region: Corresponding to the spatially consistent warming in Central Asia, an asymmetrical west–east-orientated dipole precipitation pattern, i.e., a decrease in the west but an increase in the east, is found in the warm-season (April to September) precipitation of future projections. A similar but even stronger west–east or northwest–southeast contrast is found in the changes in total runoff and surface soil moisture in response to future warming. Most of Central Asia shows an increase in drought frequency and duration by the end of the current century, mainly caused by the consistently enhanced evaporation that roughly balances the precipitation growth after 2030. When the effect of temperature is considered, the drought area of Central Asia displays a significant upward trend under both the moderate and high emissions pathway. However, in the east of the region, including Northwest China and western Mongolia, warming and wetting tendencies under the future warming climate are apparent, regardless of the drought definition.

Keywords

• Drought
• Hydroclimatology
• Future projection
• Precipitation
• Central Asia
• CMIP6