6.25km高分辨率降尺度数据对21世纪长江经济带极端气候事件及其风险的集合预估

An Ensemble Projection of Extreme Climate Events and Related Risk Exposures in the 21st Century in the Yangtze River Economic Zone Using High-Resolution(6.25 km)Downscaling Datasets

使用基于动力降尺度和统计降尺度方法得到的RCP4.5情景下的6.25 km高分辨率联合降尺度预估数据集,对长江经济带未来极端气候事件及其造成的风险展开评估和预估.结果表明:降尺度预估数据能较好的再现各极端温度指数和大部分极端降水指数的空间分布,但一些极端降水指数的偏差略大.未来长江经济带极端热事件将增加,冷事件减少;长江中游东部和下游的极端降水事件将增加,上游地区东南部发生干旱事件的可能性大.长江经济带以及上游、中游和下游3个分区的高温事件和强降水事件的国内生产总值(GDP)暴露度都将增加;人口暴露度呈先增后降的变化趋势.高温事件的GDP暴露度的分布因子和非线性因子的贡献同样重要,人口暴露度中分布因子的影响更大;强降水事件的暴露度主要取决于GDP或人口分布因子.

The 6.25 km high-resolution downscaling projection datasets under the RCP4.5 scenario based on a combined dynamical and statistical downscaling method are used to evaluate and project the future extreme climatic events and the associated risks in the Yangtze River Economic Zone(YREZ).The results show that the datasets can well reproduce the spatial distribution of all temperature extremes and most precipitation extremes,providing a reliable forecasting capability.However,Slightly larger deviations in some extreme precipitation indices The heat events will increase,while the cold events will decrease substantially in the YREZ.Extreme precipitation is projected to increase in the lower and eastern middle reaches and decrease in the east and south upper reaches.The gross domestic product(GDP)exposure to heat events and heavy rainfall showed an increasing trend in the 21st century in YREZ,most significantly in the lower reaches.Meanwhile,population exposure increased and then decreased in the 21st century.The contribution of the distribution factor and the non-linear factor are equally important for GDP exposure to high events,while the distribution factor having a greater impact in population exposure.The GDP/population exposure to heavy rainfall mainly depends on its distribution factor.