摘要
[目的]分析自贡市近50年来降水变化特征。[方法]利用自贡市1961～2010年3个测站逐日降水资料,运用线性趋势法、累计距平法等数理统计方法,研究了近50年来自贡市年、季、月降水总量与雨日的气候变化特征。[结果]自贡市年降水量总体呈减少趋势,其变化倾向率为-28.0 mm/10a。年雨日明显减少,且雨日的减少比降水量的减少明显得多,其变化倾向率为-5.6 d/10a,雨日的减少主要表现为小雨日数的减少。夏、秋、冬季降水量均呈负趋势,且四季的雨日都呈负趋势,其中,秋季的雨量和雨日减少最明显也最多。逐月降水量呈单峰型分布,逐月降水日数呈双峰型分布。自贡各地年内出现的各级雨日数几乎一致,且不同强度雨日随量级的增加而减少。年降水量和雨日数的同步减少是自贡市近50年来降水变化的一个明显特征。[结论]总的来说,自贡市自然降水资源正趋于减少,秋干明显。
[ Objective ] The research aimed to analyze variation characteristics of the precipitation in Zigong City in recent 50 years. [ Method ] Based on daily precipitation data of the three observation stations in Zigong City from 1961 to 2010, linear tendency method and accumulated anomaly method were adopted to analyze climatic change characteristics of the annual, seasonal, monthly rainfalls and rain days in Zigong City in recent 50 years. [ Result] The annual rainfall overall presented a decreasing trend at the variation tendency rate of -28.0 mm/10a inZigong City. The annual rain days obviously declined at the variation tendency rate of - 5.6 d/10a. The decline of rain days was more obvious than that of the rainfall. Decline of the light rain days was especially serious. Not only trends of summer, autumn and winter rainfalls were all negative, but also trends of four-season rain days were all negative. Reductions of autumn rainfall and rain days were the most remarkable and the largest in magnitude. Monthly rainfall presented single-peak type distribution, and monthly rain days presented double-peak type distribu- tion. Days of each-level rain within one year in each area of Zigong City were nearly consistent. Moreover, rainy days decreased as magnitude increased. An obvious characteristic of the precipitation variation in Zigong City in recent 50 years was synchronal decrease of the annual rainfall and rain days. [ Conclusion] In general, the natural rainfall resource in Zigong City was tending to reduce, and autumn drought was obvious.
出处
《安徽农业科学》
CAS
2012年第9期5546-5549,共4页
Journal of Anhui Agricultural Sciences
关键词
自贡市
降水量
雨日
变化特征
Zigong City
Rainfall
Rain days
Change characteristic
