CMIP6‐projected changes in drought over Xinjiang, Northwest China

Abstract

AbstractXinjiang, located in Northwest China, is a typical arid and semiarid region. In this region, frequent droughts have caused great losses in agricultural production and social economy. Therefore, changes in drought over Xinjiang have attracted considerable attention. This study projects the drought changes over Xinjiang during the 21st century, based on the Coupled Model Intercomparison Project Phase 6 (CMIP6) simulations under three Shared Socioeconomic Pathways (SSPs). The Standardized Precipitation Evapotranspiration Index (SPEI) is applied to measure drought variation. After quantitatively evaluating the performance of 25 CMIP6 models in annual and seasonal precipitation and evapotranspiration in Xinjiang during 1995–2014, we select 13 preferred models for projection. The projection results show significant decreasing trends in annual SPEI during 2021–2100 in Xinjiang, with the trends of −0.1/10a, −0.1/10a and −0.2/10a under SSP1‐2.6, SSP2‐4.5 and SSP5‐8.5, respectively. For seasons, the projected decreasing trends of SPEI in summer, autumn and spring are greater than that in winter. Relative to 1995–2014, during 2081–2100, moderate and severe droughts are projected to occupy a major increase in drought areas in Xinjiang under the three scenarios. In addition, drought tends to become more frequent and intense and last longer especially under higher scenarios. Under SSP5‐8.5, the projected regionally averaged drought frequency, intensity and duration increase by 15%, 8% and 1 month at the end of the 21st century. On the whole, the intermodel uncertainties of the projected changes in drought over Xinjiang increase with time in each emission. The findings of this study can provide information for decision makers to develop drought adaptation measures.