A comparative assessment of CMIP5 and CMIP6 in hydrological responses of the Yellow River Basin, China

Abstract

Investigation of the role of multiple general circulation model (GCM) ensembles in obtaining comprehensive knowledge of hydrological responses across the Yellow River Basin (YRB), China, is still of substantial importance. This study evaluates the performance of the Coupled Model Intercomparison Project Phase 6 (CMIP6) models in simulating the hydrological regime in the YRB and compares the results with those from CMIP 5 (CMIP5). The comparison is performed between 21 GCMs from CMIP6 under three Shared Socioeconomic Pathway scenarios and 18 GCMs from CMIP5 under three Representative Concentration Pathway scenarios. Raw CMIP outputs are first corrected and downscaled by the Bias Correction and Spatial Disaggregation methods, and the bias-corrected GCM outputs are then employed to drive the Soil and Water Assessment Tool hydrological model and project streamflow. After correction and downscaling, areal averages for future changes (relative to 1971–2000) of temperature and precipitation are found larger in CMIP6 than in CMIP5. The emblematic annual mean temperature of CMIP6 increases by 1.64–2.20 and 2.31–5.29 °C for the future period of 2026–2055 and 2066–2095, while the counterpart of CMIP5 is 1.92–2.39 and 1.68–4.76 °C, respectively. In terms of precipitation, for CMIP6, it increases by 3.45–4.70 and 6.77–15.40%, and for CMIP5 by 2.58–2.96 and 3.83–9.95%. It is further concluded that: (1) future streamflow will probably decrease less under CMIP6 than that under CMIP5 in most cases, and climate changes of this kind will affect regional water supply and security in the YRB; (2) uncertainty in the projected streamflow is dominated by GCMs uncertainty with the contribution rate of >75%; (3) the streamflow is more sensitive to precipitation changes in comparison with temperature changes in the near future. In contrast, streamflow reduction is more attributed to an increase in temperature with a contribution rate of almost >60% than in precipitation in the far future.

Development of high‐resolution monthly precipitation datasets for geomorphological applications in the Tianshan Mountains from 2000 to 2050

“…This study indicated that precipitation will increase faster in the next 30 years than in the past, and the rate of increase under the SSP245 scenario was projected to be higher than that under the RCP4.5 scenario (Figure 6). The above results have been validated by other studies (Guo et al, 2022; Li et al, 2021; Piao et al, 2021). In the Yellow River Basin, relative to the period of 1971–2000, there was a projected increase in precipitation of 3.45–4.70% and 6.77–15.40% during 2026–2055 and 2066–2095, respectively, in CMIP6.…”

“…In the Yellow River Basin, relative to the period of 1971–2000, there was a projected increase in precipitation of 3.45–4.70% and 6.77–15.40% during 2026–2055 and 2066–2095, respectively, in CMIP6. In comparison, for CMIP5 there was a projected increase of 2.58–2.96% and 3.83–9.95% during the same time periods (Guo et al, 2022). In southern South America and western North America, the rate of change in total precipitation for CMIP6 in the future under various scenarios was always greater than that for CMIP5 (Li et al, 2021).…”

Assessment of Rainfall And Temperature Trends in The Yellow River Basin, China from 2023 to 2100

“…The YRB is situated in northern China (32°-42°N, 95°-120°E), and is approximately 1900 km long from east to west and 1100 km wide from north to south, with a basin area of 7.95×10 5 km² (Guo et al, 2022) (Fig. 1).…”

Assessment of Rainfall and Temperature Trends in the Yellow River Basin, China from 2023 to 2100

“…The YRB is situated in northern China (32 • -42 • N, 95 • -120 • E), and is approximately 1900 km long from east to west and 1100 km wide from north to south, with a basin area of 7.95 × 10 5 km 2 [19] (Figure 1). The area has a continental climate, vast territory and numerous mountain ranges.…”