“雅安天漏”降水变化气候特征的分析  

Analysis on the Climatic Characteristics of the Precipitation Variations at“Ya'an Sky-leakage”

作　　者：周秋雪[1,2,3] 李跃清[1] 蒋兴文[1] 张静[1,4] 

机构地区：[1]中国气象局成都高原气象研究所,成都610072 [2]四川省气象台,成都610072 [3]高原与盆地暴雨旱涝灾害四川省重点实验室,成都610072 [4]中国民航飞行学院新津分院,四川新津611431

出　　处：《自然资源学报》2016年第2期343-353,共11页Journal of Natural Resources

基　　金：国家重点基础研究发展计划项目(2012CB417202);国家公益性行业(气象)科研专项经费项目(GYHY201006053;GYHY201106003);西南区域气象中心重大业务项目(2010-1);西南区域强降水预报创新团队;西南区域重大业务项目(2014-3);四川省气象局科学技术研究开发课题(川气课题2015-青年-03)~~

摘　　要：论文基于1951—2008年逐日降水资料和1969—2000年逐小时降水资料,应用统计诊断分析方法,研究了青藏高原东侧雅安降水量、降水频率的多时间尺度变化特征。结果表明:与整个四川省的降水变化一致,近58 a"雅安天漏"的年降水总量和年雨日是减少的,并且后者比前者减少得更加显著;降水量在20世纪90年代的显著减少是雨日和雨强变化共同影响的结果;除冬季外,春、夏、秋三季的降水量和雨日均呈减小趋势,其中秋季减少最明显;汛期降水量减少占年降水量减少量的92.7%,汛期雨日的减少比降水量显著,占年雨日减少的62.9%;21世纪初期后,"雅安天漏"强降水月份减少,雨日集中时段缩短;"雅安天漏"夜雨特征突出,夜间降水量和频次远远大于白天,呈单峰单谷结构,降水谷值到峰值增加速率是峰值到谷值衰减速率的2倍,易夜间形成强降水,具有明显持续性。进一步分析发现,雅安不仅夜雨量和发生频次减小,而且降水表现为峰值出现时间提前、向前半夜移动的变化特征。Based on the daily precipitation data during 1951-2008 and hourly precipitation data during 1969-2000 at Ya＇an station, multiple time scale variations of precipitation amount and precipitation frequency at ＂Ya＇an sky-leakage＂ which locates at the eastem edge of the Tibetan Plateau are investigated. The result of conventional statistical diagnostic method shows that the annual precipitation and annual rain days are reducing during the last 58 years at ＂Ya＇an sky- leakage＂, and the decrease of rain days is more obvious than that of precipitation. Particularly, the annual precipitation sharply declined after the 1990s due to the decreased of both rain days and rainfall intensity. Except in winter, the trends of precipitation in other three seasons are all downward. Among all seasons, the reductions of precipitation and rain days in autumn are the most obvious. The precipitation reduction in flood season accounts for 92.7% of the annual precipitation reduction. The decrease of rain days in flood season is more obvious than that of precipitation, which account for 62.9% of the annual rain days＇ reduction. After the beginning of the 21st century, the strong precipitation months decreased, and the aggregated period of rain days shortened significantly. The night rainfall is the most prominent characteristic at ＂Ya＇an sky-leakage＂. Both the amount and frequency of rainfall in the night are much more than in the daytime. There is a peak of the rainfall in the night, and the increase rate from valley to peak is twice as much as the decrease rate from peak to valley, so it is easy to form heavy rain at night, and it is obviously lasting. However, further analysis found that not only the amount and frequency of night rainfall reduced at ＂Ya＇an sky-leakage＂, but also the precipitation peak occurred earlier than before.

关 键 词：雅安天漏 降水量 降水频率 雨日 多时间尺度 

分 类 号：P426.6[天文地球—大气科学及气象学]