| 近80年宝鸡市旱涝变化特征分析 |
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| 引用本文： | 李建芳.近80年宝鸡市旱涝变化特征分析[J].干旱区资源与环境,2012(10):13-17. |
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| 作者姓名： | 李建芳 |
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| 作者单位： | 宝鸡市气象局; |
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| 摘 要： | 文中使用1934-2010年5-9月降水总量资料,分析研究宝鸡近80a旱涝演变规律。结果表明:宝鸡市近80a有向干旱发展的趋势,并且以0.12次/10a的速度增加;旱涝出现的频率为39%和28.6%;旱涝演变具有24a左右的长周期和2a的短周期;20世纪40年代、80年代以偏涝为主;70年代、90年代和21世纪头10年以偏旱为主。宝鸡市近80a以来,年Z指数明显下降,其下降速度为0.16/10a。1953-1990年涝年多、旱年较少,1993年以后旱年多、涝年很少,近年来有旱涝交替的特点。四季的Z指数变化趋势不同,冬、夏季Z指数变化不大,冬季呈略上升趋势;夏季呈微弱的下降趋势;春、秋季呈明显的下降趋势,表明干旱趋势增强,春季最明显,秋季次之。春季涝、旱和正常年基本各占1/3;夏涝、秋涝、冬旱的发生频率高。各季旱涝变化都具有2a的周期。研究结果对旱涝趋势预测和防灾减灾具有一定的参考价值。
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| 关 键 词： | 旱涝变化 Z指数 四季 宝鸡市 |
Characteristics of drought and flood changes in Baoji |
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| Abstract: | Based on the daily precipitation records in May to September from1934 to 2010 in Baoji City of Shaanxi Province,the characteristic changes of drought and flood were analyzed.The results showed that it was a drier tendency at a rate of 0.12 times per decade in the recent 80 years.The occurrence probability of drought and flood were 39% and 28.6%.They had two periods which were 24a and 2a.Flood events were mostly happened in 1940s and 1980s,but drought events appeared in 1970s,1990s and 2000s.What's more,Z-index was decreased significantly at the rate of 0.16 per decade in nearly 58 years.From 1953 to 1990,flood was more than drought,but the result reversed after 1993,then it was alternated drought and flood in recent years.The variation trends of Z-index in every season were different.Z-index trends changed little in summer and winter,which were a slightly upward in winter and a thin downward in summer.But it showed an obviously downward trend in spring and autumn.It means that the trend of drought increased,and it was the most obvious in spring firstly and then in autumn.Flood,drought and normal years took up each 1/3 in spring,and summer flood,autumn flood,winter drought had high frequency of occurrence.The period of drought and flood was 2 years in each season.Those results were crucial to the prediction of drought and flood forecasting and disaster prevention. |
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| Keywords: | the characterization of drought and flood Z-index four seasons Baoji City |
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