1960-2017年江淮地区降水的时空变化特征

Spatiotemporal Variability of Precipitation in the Jianghuai Region During 1960-2017

[目的]探究江淮地区降水量的时空变化特征,并在此基础上研究了大气环流因子对降水量的影响,为江淮地区水资源管理和灾害防治提供科学基础。[方法]基于1960—2017年江淮地区15个气象站点的逐日降水及大气环流数据,采用Mann-Kendall趋势检验、累计距平曲线、小波分析、交叉小波变换及小波相干方法,揭示了江淮地区时空变化特征及影响该地区降水量的因素。[结果]江淮地区降水量存在多尺度的周期性震荡,其中冬季降水量表现为显著增加趋势(p<0.05),经历最少次偏多—偏少过程,且存在55.6 a的主周期;年、夏季降水量呈不显著增加趋势,经历最多次偏多—偏少过程,但其在该地区南部多呈显著性变化;春、秋季降水量呈不显著下降趋势,全地区不存在显著性变化站点。该地区降水量与大气环流指数在年际尺度上均存在一定的共振周期,东亚夏季风(EASM)对其影响最显著;南方涛动指数(SOI)对其影响最不显著。[结论]江淮地区降水在年际及季节性尺度上时空变化特征具有明显差异,且在年际尺度上受大气环流一定的显著影响,研究结果能为该地区科学制定水资源规划、预防气候型风险、达到生态平衡提供理论支撑。

[Objective]The aim of the study is to explore the spatial and temporal variation characteristics of precipitation in the Jianghuai region,and on this basis,the influence of atmospheric circulation factors on precipitation was investigated to provide a scientific basis for water resources management and disaster prevention and control in the Jianghuai region.[Methods]Based on daily precipitation and atmospheric circulation data from 15 meteorological stations in the Jianghuai region from 1960 to 2017,this study used Mann-Kendall trend test,cumulative distance level curve,wavelet analysis,cross wavelet transform and wavelet coherence methods to reveal the spatial and temporal variation characteristics of the precipitation and the factors influencing the precipitation in the Jianghuai region.[Results]The precipitation in Jianghuai region had a multi-scale periodic oscillation,in which winter precipitation showed a significant increasing trend(p<0.05)and experienced the least over-under process,and there was a main cycle of 55.6-year.Annual and summer precipitation showed a non-significant increasing trend and experienced the most overunder process,but it mostly showed significant changes in the southern part of the region.The precipitation in spring and autumn showed an insignificant downward trend,and there were no significant change stations in the whole region.There was a certain resonance cycle between precipitation and the Atmospheric Circulation Index on an interannual scale,with the East Asian Summer Monsoon(EASM)having the most significant influence and the Southern Oscillation Index(SOI)having the least significant influence.[Conclusion]The spatial and temporal characteristics of precipitation in the Jianghuai region varied significantly on interannual and seasonal scales,and were significantly influenced by the atmospheric circulation on interannual scales.The results of this study can provide theoretical support for scientific water resources planning,prevention of climate-based risks and achievement of ecological balance in the region.