考虑不确定度的POT模型在洪水重现期分析中的应用研究

以淮河紫罗山子流域出口日平均流量数据为研究对象,基于超阈值(POT)模型,采用最大似然法估计广义Pareto(GP)分布参数并计算出重现期水平和相应的置信区间范围。拟合优度检验结果显示POT模型在扩大洪水样本提高使用效率的同时,对样本经验点据的适线性也较好。通过对5种时段长度的水文实测流量数据重现期计算发现:实测数据长度对重现期计算结果不确定性有重要影响,在工程水文中推荐选取恰当的置信区间上界作为设计值加以解决。

Floods Return Peritd Calculation with Uncertainty Analysis Via POT Model

Choosing the observed daily data from the Ziluoshan Stationin the Huaihe River Basin, this paper used the maximumlikelihood method to estimate Generalized Pareto (GP) distribution parameters for calculating the recurrence interval level and confidence interval with the Peak of Threshold (POT)approach. The goodness-of-fitting test show that the POT model canget a betterempirical sample point while enlarge the flood sample. The sensitive analyses of different time duration flood data show that the time duration has a significant impact on the recurrence interval calculation.