Analysis of Variation in Runoff of the Yi River Main Stream and Its Influencing Factors During 1955-2013
Based on the runoff and precipitation data measured by Gegou Hydrological Station in Yi River basin during 1955-2013, and using statistical methods such as coefficient of variation, Kendall rank correlation coefficient, rescaled range analysis, Mann-Kendall test, double cumulative curve, multi-temporal scale variation of the runoff about Yi River main stream and its influencing facctors are analyzed.The result shows that: (1) Runoff of Yi River mainstream fluctuates greatly in the whole year, from June to September accounts for 78.35% and extreme ratio is 16.53.(2)The extreme ratio and coefficient of variation of the inter-annual runoff variation are 16.98, 0.77, respectively.The high water year and low water year appears alternately and the duration is inconsistent.(3)The runoff variation rate is-5.715(m3/s)/10a, which shows the downward trend overall of Yi River mainstream runoff, which is consistent with the conclusion of the cumulative filter method.By taking use of Kendall rank correlation coefficient method, the M valve of the annual average runoff is-2.45,(I-2.45|>1.96, the corresponding critical value of a=0.05 significance level a=0.05 is 1.96) , and the level is significant.Hurst index is 0.58 by resealed range analysis, which indicates the decreasing trend of Yi River main stream would be continuous.According to Mann-Kendall test, mutation time point of the main stream runoff occurs in 1976.(4) The main factors influences runoff variation of the Yi River is human activities, and the impact proportion of precipitation and human activities on runoff varies a lot during different periods.
Yi River main stream runoff variation rescaled range analysis Mann-Kendall test double cumulative curve precipitation variation human activities
XIAO Xue LI Chuanqi MA Jie YANG Yuheng
School of Civil Engineering, Shandong University, Jinan, China
国内会议
深圳
英文
210-217
2017-11-10（万方平台首次上网日期，不代表论文的发表时间）