中文摘要：

运用Cox回归模型、月频率法以及离散指数法,研究了新疆塔里木河（塔河）流域8个水文站点POT抽样和5个区域洪水序列时间集聚性特征以及受低频气候变化的影响。结果表明：受气候变化的影响,塔河流域洪水序列呈现显著集聚性特征,洪水发生频率高的时期往往也是大量级洪峰集中发生的时期,这是塔河流域洪灾损失居高不下的主要原因;Cox回归模型拟合的气候指标系数值为正值的站点和区域,气候指标正相位导致相同超过概率的洪水发生时间提前,而相同发生时间的洪水发生超过概率降低,气候指标值为负值时则相反;塔河流域大部分水文站点和区域洪水发生的超过概率均对气候指标变化有较好响应,这一现象有利于塔河流域洪水风险控制与洪灾管理;塔河流域站点洪水序列多无年际集聚性现象,而区域洪水序列的年际集聚性特征显著。

英文摘要：

Temporal clustering of magnitudes and times of occurrence of floods in the Tarim River basin recorded at 8hydrological stations located in 5 states was analyzed using the Cox regression model and monthly frequencies of flood occurrences and dispersion methods under the impact of low-frequency climate change. Results indicated that： under the effect of climate change,there was a significant temporal clustering in the flood process in Tarim River basin. Periods of high flood frequencies trended to be the periods of high flood mitigation seriously influenced by regional flood control which was the main reason for large flood-induced losses in the Tarim River basin. The positive phase of climate indices resulted in the early occurrences of floods for the same exceedance probabilities and decreasing exceedance probabilities for the same time of flood occurrence at the hydrological stations and in the region,which both had positive coefficient values fitted by the Cox regression model with climate indices as covariates,while the negative phase of climate indices had an opposite effect. The exceedance probability of flood occurrence time preferably responded to low-frequency change,which was advantageous for flood control and flood risk management in the Tarim River basin. The majority of hydrological stations did not reveal any inner-annual clustering of flood occurrences when obtained by POT sampling,while regional flood occurrences had significant clustering.