CMIP6模式对云南区域性干旱过程的模拟评估及预估

21世纪以来，云南频繁发生全省性干旱过程，造成严重的灾害。未来在气候变化背景下云南全省性干旱过程将如何变化尚未得到充分研究。基于16个第六次耦合模式比较计划(CMIP6)的模式结果和区域性干旱过程监测评估方法，研究了云南省区域性干旱过程历史时期的特征和未来不同排放情景下的可能变化。结果显示，适当订正后的CMIP6模式能较好地模拟出近54年云南省区域干旱事件的特征，模式偏差主要表现为夏季降水偏多、10—11月降水偏少。未来54年在三种排放情景下，云南省区域性干旱过程发生次数将增加1.1～4.7次，持续日数将增加2.6～4.0日，影响范围将增加0.2～0.6站，累计强度将增加0.1～0.2。未来发生在干季内的干旱过程次数将减少，但持续日数、影响范围、累计强度都将增加；由干季延伸至雨季的干旱过程次数、持续时间、累计强度都将增加；发生在雨季内的干旱过程次数和影响范围将增加、累计强度将减小。滇西北、滇东北等受干旱过程影响较轻的地区未来也将更容易受到干旱过程的影响。上述结果表明未来云南省全省性干旱过程将加强。

EVALUATION AND FUTURE PROJECTION OF REGIONAL DROUGHT EVENTS IN YUNNAN PROVINCE USING CMIP6 MODEL PRODUCTS

Yunnan was strike by a series of province-wide severe drought processes since the 21st century. The future change of province-wide drought process in Yunnan under the context of climate change remains unclear. Based on 16 CMIP6 model outputs and the monitoring and assessment method for regional drought process, the present study investigated the characteristics of the regional drought process in recent years as well as its future projections in Yunnan under different emission scenarios. The results showed that after bias correction, the CMIP6 models could reasonably simulate the characteristics of the regional drought processes in Yunnan in recent 54 years. The CMIP6 models overestimated the precipitation in summer and underestimated the precipitation in October and November. In the future and under three different emission scenarios, the number of regional drought processes in Yunnan would increase by 1.1~4.7 times, the duration would increase by 2.6~4.0 days, the influencing range would increase by 0.2~0.6 stations, and the accumulated strength would increase by 0.1~0.2. The frequency of drought process during dry season would drop, but the duration, influencing range, and cumulative intensity would increase. The drought process occurred in dry season and prolonged to wet season would become more frequent and have longer duration as well as stronger accumulated strength. The drought process during rainy season would become more frequent with longer duration and weaker accumulated strength. The northwestern and northeastern parts of Yunnan, which were less affected by the regional drought processes in history, would become more vulnerable to the regional drought processes in the future. These results suggest that the province-wide drought process in Yunnan will strengthen in the future.