淮河流域极端径流的时空变化规律及统计模拟

Temporal and Spatial Variations and Statistical Models of Extreme Runoff in Huaihe River Basin

以淮河流域蚌埠闸以上20个水文站点1956-2010年日径流量观测数据资料为基础,采用游程检验、趋势检验和Mann-Kendall检验法分析年最大日径流量的变化规律。分别采用年最大值法(annual maximum,AM)和超门限峰值法(peaks over threshold,POT)抽取径流序列样本,运用广义极值分布(generalized extreme value distribution,GEV)和广义帕累托分布(generalized Pareto distribution,GPD)两种极值统计模型对规范化样本进行拟合,分析淮河流域极端径流的时空变化规律。研究表明:1956-2010年,淮河流域蚌埠闸以上的研究站点中,10个站点的年最大日径流量有减少的趋势,另外10个站点有不显著的增加趋势。极端径流事件大多发生在20世纪60、70年代,且以汛期居多。淮河流域的极端径流主要来自淮河干流、淮南山区和伏牛山区。使用Kolmogorov-Smirnov(K-S)法检验发现,GEV和GPD分布分别能较好的拟合AM和POT序列。采用百分位阈值法、平均超出量函数图法和超定量洪峰法三种方法选取阈值,对于淮河流域的极端径流事件模拟而言,百分位阈值法较好。

Based on the daily runoff data from 20 hydrological stations during 1956-2010 above the Bengbu Sluice in the Huaihe River Basin,run test,trend test and Mann-Kendall test are used to analyze the variation trend of annual maximum runoff series.The annual maximum series（AM） and peaks over threshold series（POT） are selected to describe the extreme distributions of GEV and GPD.Temporal and spatial variations of extreme runoff in the Huaihe River Basin are analyzed.The results show that during the period 1956-2010 in the Huaihe River Basin,annual maximum runoff at 10 stations have a negative trend,while the other 10 stations have a positive trend which is not significant.The maximum runoff event almost occurred in the flood period during the 1960s and 1970s.The extreme runoff events in the Huaihe River Basin mainly occured in the mainstream of the Huaihe River,Huainan mountain areas,and Funiu mountain areas.Through Kolmogorov-Smirnov test,GEV and GPD distributions can be well fitted with AM and POT series respectively.