摘要
利用数理统计学方法计算了北京地区1724年至2009年间降水的年际、年内统计特征,多年降水平均值为601.8 mm、均方差为196.7 mm、最大值为1 406 mm(1959年)、最小值为242 mm(1869年)。涝、偏涝、正常、偏旱和旱年分别为23 a、28 a、172 a、58 a和5 a。年降水与4个季度降水量的相关系数依次为:0.055、0.456、0.942和0.177。降水主要集中在6-8月份,多年的统计表明其所占比例呈下降趋势。线性拟合的结果表明:近100多年以来,北京地区的降水呈总体下降趋势,下降速率为0.89 mm/a。自相关分析表明:年降水系列的是相对独立的系列,相依性弱。Q-Q图分析和K-S检验表明:在90%的置信水平内降水系列符合正态分布,但是在95%的置信水平内,其则不符合正态分布。
Based on the monthly precipitation data of Beijing region from 1724 to 2009,this paper calculated the annual statistical characteristics by mathematical statistical methods.The annual mean precipitation is 601.8 mm,with the mean square error is 196.7mm.Also the maximum is 1406mm（1959） and the minimum is 242 mm（1869）.The mumber of years of Flood,partial flood,normal,partial drought and drought are 23,28,172,58 and 5a respectively.The correlation coefficient of annual rainfall and rainfall in the four quarters is 0.055,0.456,0.942 and 0.177.The years statistics shows a downward trend of the proportion of rainfall in 6-8 months of a year.Also,the linear regression results showed that the precipitation in Beijing area showed a general downward trend with the rate of decrease 0.89mm/a within the nearly 100 years.By autocorrelation analysis,series of rainfall is relatively independent.The Q-Q graph analyzing and K-S testing result showed that the rainfall in Beijing obeys the normal distribution when the confidence level is 90%,but within 95% confidence level which is not normally distributed.
出处
《水资源与水工程学报》
2011年第1期90-93,共4页
Journal of Water Resources and Water Engineering
基金
北京市委组织部优秀人才培养资助项目(2009D010002000002)
2010年北京市地勘局公益性地质科研项目(dkJdzky2010001)资助
关键词
降水量
数理统计方法
降水分布
北京地区
amount of precipitation
mathematical statistical
distribution of rainoff
Beijing region
