Arid Zone Research ›› 2019, Vol. 36 ›› Issue (3): 556-566.

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Projection of Future Climate Change in the Kaidu-Kongqi River Basin in the 21st Century

LI Xiao-fei1, 2, XU Chang-chun1, 2, LI Lu1, 2, SONG Jia1, 2, ZHANG Xi-cheng1, 2   

  1. 1. College of Resources and Environmental Sciences,Xinjiang University,Urumqi 830046,Xinjiang,China; 2. Key Laboratory of Oasis Ecology under Ministry of Education,College of Resources and Environmental Sciences,Urumqi 830046,Xinjiang,China

  • Received:2018-07-10 Revised:2018-11-06 Online:2019-05-15 Published:2019-05-15

Abstract: Climate change assessments on both global and regional scales rely strongly on the global climate models (GCMs) which are dominantly provided by the Coupled Model Inter Comparison Project Phase 5 (CMIP5). Based on the grid datasets of monthly air temperature and precipitation from CRU (Climate Research Unit) and 31 CMIP5 GCMS data from the Downscaled CMIP3 and CMIP5 Climate and Hydrology Projections (DCHP), in this paper the performance of three Multi-Model Ensemble Mean methods (PLS, RR and EE) in simulating the historical climate change processes was evaluated, and the optimal ensemble method was determined and estimated for predicting the future climate change in the Kaidu-Konqi River Basin in the 21st century. The results indicated that the performance of the established Partial Least Squares (PLS) model was the best in simulating air temperature and precipitation in the study area. The R values of simulated temperature were all higher than 0.64, they were obviously better than those of simulated precipitation (R = 0.19~0.36). However, there was a spatial heterogeneity in both temperature and precipitation simulations. In the 21st century, the air temperature in the 4 sub-basins of Kaidu-Kongqi River Basin would be in a significant increase trend. The increase rates of air temperature [0.58~0.67 ℃·(10a)-1] under the RCP8.5 scenario would be doubled compared with those under RCP4.5 scenario [0.25~0.31 ℃·(10a)-1]. The significant difference between the two scenarios would begin from the mid-21st century. From the perspective of entire watershed, the warming rate increased gradually from the mountainous area in the northwest to the desert in the southeast. The distribution of change rates of precipitation was slightly different under different discharge scenarios, but both of them would be in a significant increase trend. The increase rate under RCP8.5 scenario [1.22%~1.54%?(10a)-1] would be holistically higher than that under RCP4.5 scenario [0.80%~1.32%·(10a)-1].

Key words: downscale, CMIP5, air temperature, precipitation, Multi-Model Ensemble, future climate change, Kaidu-Kongqi River Basin