摘要
极端降水越来越受重视,而现有绝大多数基于降水网格数据的研究忽略了空间一致性。对此,引入考虑空间一致性的连通分量标记法,识别和定义区域性极端降水事件(Region Extreme Precipitation Events,REPE),并利用1970~2020年长江中下游0.5°×0.5°地面降水格点数据,选用线性拟合、Mann-Kendall趋势检验法、Pettitt突变检验法和置换检验法等方法分析了长江中下游近51年来REPE不同时间尺度的分布特征,揭示了不同类型ENSO事件对当年与次年REPE的影响。分析表明,年内REPE主要发生在5~9月;年际REPE总体表现为数量显著增加,尺度显著增大;在年代际时间尺度上,REPE突变发生在1993~1994年,尺度突变早于数量突变,且在突变点后期REPE相对突变点前期频数更多,尺度更大;REPE与年降水总量呈现强相关性;对于ENSO而言,总体上ENSO事件会使得事件发生的当年和次年REPE增多且尺度变大;EPC事件总体上使得当年的REPE数量上显著增加,其显著影响体现在4、5、7月;EPW事件总体上使得次年REPE尺度显著增大,其显著影响体现在事件当年12月及次年1月;而发生在CPW事件当年和次年的REPE总体上无显著变化,但在CPW事件次年7月REPE存在显著增强。研究结果可为长江中下游极端降水预报提供依据。
More and more researches focus on the evolution of extreme precipitation events.However,the spatial consistency of the extreme precipitation events has not been comprehensively investigated by the studies using grid precipitation data.In this study,the connected component labelling algorithm,which considers spatial consistency,was applied to explore regional extreme precipitation events(REPE).Based on the 0.5°×0.5°surface precipitation grid dataset from 1970 to 2020,the multi-scale temporal distribution of REPE in the middle-lower reaches of the Yangtze River and its connections with ENSO were analyzed by using linear fitting,Mann-Kendall trend test,Pettitt mutation test,and permutation test.The results show that at seasonal scale,REPE mainly occurs from May to September;At inter-annual scale,the total number and the spatial scale of REPE both increase significantly;At inter-decadal scale,the mutation of REPE occurred from 1993 to 1994,and the spatial mutation was earlier than the quantitative mutation,and in the later stage of the mutation point REPE has more frequency and larger spatial scale than in the earlier stage of the mutation point.The ENSO generally increases the number and spatial coverage of REPE in the current year and the following year.The EPC significantly increases the number of REPE in the current year,and its significant impact is reflected in April,May and July.The EPW generally makes the REPE spatial scale significantly increase in the following year,and its significant impact is reflected in December of the current year and January of the following year.While REPE that occurs in the current year event and the following year of the CPW does not change significantly,but there is a significant increase in REPE in July of the following year of the CPW.These results can provide a basis for the forecast of extreme precipitation in the middle-lower reaches of the Yangtze River.
作者
李培熙
余钟波
江鹏
吴昌贤
LI Pei-xi;YU Zhong-bo;JIANG Peng;WU Chang-xian(State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Hohai University,Nanjing 210098,China;Joint International Research Laboratory of Global Change and Water Cycle,Hohai University,Nanjing 210098,China;College of Urban and Environmental Sciences,Peking University,Beijing 100871,China)
出处
《水电能源科学》
北大核心
2022年第1期1-5,共5页
Water Resources and Power
基金
国家重点研发计划(2016YFC0402710)
国家自然科学基金项目(51539003,41761134090)
水文水资源与水利工程科学国家重点实验室专项经费(20195025612,20195018812,520004412)。
关键词
长江中下游
区域性
极端降水
ENSO
middle-lower reaches of the Yangtze River
region
extreme precipitation
ENSO
