关键词: 降水集中度;降水集中期;突变检验;遥相关因子;长江流域;

Abstract: Characteristics of precipitation temporal concentration are important for drought and flood prevention in watershed.Based on the precipitation data of meteorological stations in the Yangtze River Basin from 1960 to 2020,the index of precipitation concentration degree(PCD)and precipitation concentration period(PCP)were calculated.The moving t-test, cross-wavelet, and wavelet-coherence analysis were used to identify and test the abrupt change of precipitation temporal concentration index sequence, and the spatiotemporal characteristics of PCD,PCP and their response to teleconnection factors were analyzed.The conclusions are as follows:(1)The abrupt changes of PCD and PCP in the Yangtze River Basin occurred around 1988.The PCD and PCP were generally incremented from southeast to the northwest before and after the mutation.After the mutation, the intra-annual precipitation distribution tended to be uniform, and the precipitation concentration period was advanced.(2)There was a resonance period between PCD,PCP,and PDO(pacific decadal oscillation),AO(Arctic oscillation),ENSO(El Nino)and SS(sunspot).PDO and ENSO interacted more significantly with PCD and PCP,indicating that these teleconnection factors may be one of the important factors leading to the abrupt changes of precipitation concentration characteristics in the Yangtze River Basin.The research results can provide technical support for disaster prevention, ecological management and water resources management in the Yangtze River Basin.

Key words: precipitation concentration degree; precipitation concentration period; abrupt change test; teleconnection; Yangtze River Basin;