1951-2012年渭河流域降水频次变化特征分析  

Frequency of precipitation for the Weihe River Basin during 1951-2012

作　　者：刘闻[1] 曹明明[1] 刘琪[1] 王涛 李苒[3] 

机构地区：[1]西北大学城市与环境学院,陕西西安710127 [2]陕西延长石油(集团)有限责任公司研究院,陕西西安710075 [3]西安文理学院文化与旅游学院,陕西西安710065

出　　处：《干旱区地理》2015年第1期18-24,共7页Arid Land Geography

基　　金：西北大学科学研究基金:渭河流域关中段径流敏感性研究;西北大学科研启动基金(PR14066)

摘　　要：利用渭河流域26个气象站点1951-2012年的逐日及逐年降水数据,分析流域降水频次的变化特征及其相关影响。结果表明：（1）年降水频次在空间上表现出由北向南逐渐递增的趋势,最高年降水频次为111.39 d·a^-1,最低年降水频次为67.77 d·a^-1。强降水频次在空间上表现出由西北向东南逐渐递增的趋势,高值区最高年强降水频次为8.10 d·a^-1,低值区最低年强降水频次为1.99 d·a^-1。（2）年降水量与强降水频次Pearson相关系数〉0的区域占到总流域面积的96.59%,〉0.6-〈1的区域占到了总面积的74.14%,呈现为强相关或者极强相关,Pearson相关系数为负数,且呈现强相关或极强相关的区域只占到了总面积的0.8%。（3）强降水频次在一定阶段符合幂律分布。在拟合趋势线中间会发生转折点,强降水频次的规模较大时,拟合方程为y=198.9 x-1.199（R^2=0.901 8,P〈0.01）,强降水频次较小时拟合方程为y=113 466 x-5.402（R^2=0.983,P〈0.01）。幂律分布规律可以深层次的解释强降水是引发渭河流域洪灾的重要影响因素。Using precipitation data of about 26 stations located in the Weihe River Basin during 1951-2012,the paper analyzed the frequency of precipitation and its impacts to the Weihe River basin. Frequency of precipitation in the Weihe River exhibits a marked seasonality,with the heavy rainfall concentrated in the period July-October.Mann-Kendall test are used to examine the abrupt changes of precipitation frequency of different level and average precipitation. The results showed as follows：（1）the spatial distribution for frequency of precipitation gradually increase from north to south,namely,the highest frequency of precipitation in high value areas is 111.39 d·a^-1,the lowest frequency of precipitation in low value areas is 67.77 d·a^-1.heavy precipitation exhibited increased gradually from northwest to southeast,the highest frequency of precipitation in high value areas is 8.10 a·a^-1,the lowest frequency of precipitation in low value areas is 1.99 d·a^-1. In the past 48 years,high correlation existed between annual precipitation and the frequency of heavy precipitation, the area exhibited positive correlation account for 96.59% of the total watershed area,and the area exhibited negative correlation account for 3.41%. The paper also found that the frequency of heavy precipitation conforms to the power-law distribution in a certain stage. There is a turning point in the middle of the fitting line,when the scale of frequency of heavy precipitation is larger. Power law distribution laws can explain that heavy precipitation is an important factor which triggered floods of Weihe River basin. The research of precipitation frequency,to a certain extent,is helpful for understanding spatio-temporal distribution of extreme disasters scientifically,and for having scientific management and taking preventive measures.

关 键 词：降水频次 M-K检验 Pearson相关系数 渭河流域 

分 类 号：P426.6[天文地球—大气科学及气象学]