盘龙河流域极端降水时空变化特征分析

Spatial-temporal Variation Characteristics of Extreme Precipitation in Panlong River Basin

【目的】研究盘龙河流域极端降水的时空分布特征。【方法】基于盘龙河流域19个雨量站1978—2016年的日降水数据,根据百分位法定义极端降水事件,选择年极端降水量、降水时间和降水强度3个指标,利用线性回归、Mann-Kendall、小波变换及EOF分析极端降水的时空分布特征。【结果】时间上,过去40年盘龙河流域的极端降水量、降水时间和降水强度均呈上升趋势并在2012年发生突变;极端降水量和降水时间存在约6 a、9 a和15 a的周期变化,降水强度存在7 a和15~17 a的周期变化,15 a为3个指标的主周期。空间上,年极端降水量主要表现为全区一致型,极端降水时间和降水强度除个别站外也表现为全区一致型,总体上3个指标呈现由南向北逐渐减少的变化特征。【结论】受太平洋副热带高压影响,盘龙河流域尤以其南边未来的洪涝灾害更加严峻,给盘龙河流域的防洪减灾带来挑战,需进一步提高灾害风险管理和应对气候变化的能力。

[Purposes]To study the spatial-temporal characteristics of extreme precipitation of Panlong River Basin.[Methods]Based on the daily precipitation data of 19 precipitation stations in Panlong River Basin from 1978 to 2016,the extreme precipitation events were defined according to the percentile method,and the annual extreme precipitation,precipitation time and precipitation intensity were selected to identify region and time distribution features of extreme precipitation by using linear regression,Mann-Kendall,wavelet transform and EOF.[Results]In time,the extreme precipitation,precipitation time and precipitation intensity of Panlong River Basin over the past 40 years all showed a rising trend,and a sudden change occurred in 2012;extreme precipitation and precipitation time had periodic changes of about 6 a,9 a and 15 a,precipitation intensity had periodic changes of about 7 a,15-17 a,and 15 a was the main cycle of the three indicators.Spatially,the annual extreme precipitation was mainly consistent in the whole region,and the time and intensity of ex-treme precipitation were also consistent in the whole region except for individual stations.On the whole,the three indicators showed a decreasing trend from south to north.[Conclusion]Affected by the Pacific subtropical high,the flood disaster in the Panlong River Basin,especially in the south,will be more severe in the future,which will bring challenges to the flood control and disaster reduc-tion of the Panlong River Basin.It is necessary to further improve the ability of disaster risk manage-ment and coping with climate change.