开都河流域极端水文事件变化及其对气候的响应

基于开都河流域1972—2012年大山口水文站及巴音布鲁克气象站资料，采用累积频率法定义极端水文事件的阈值，分析了极端水文事件频次的年内年际变化、场次分布特征及其对区域气候变化的响应。结果表明:极端水文事件具有极不稳定的特性。年内分配不均且集中度较高，极端洪水事件主要集中在7月，极端枯水事件主要集中在2月；年际变化极不稳定，且偏离正态分布的程度较高。极端洪水事件总体呈增长趋势，并在1986年发生突变；极端枯水事件则呈减少趋势，突变点为1993年。极端洪水频次与降水量相关性较高，极端枯水频次与气温的负相关性较高。

Extreme Hydrological Events and Its Response to Climate Change in the Kaidu River Basin

Based on the daily discharge and meteorological date from 1972 to 2012 at the Dashankou hydrological station and Bayinbuluke weather station in the Kaidu River Basin, the characteristics of extreme hydrological events (EHE) were investigated, the threshold value was determined by the cumulative frequency method, the inner-annual and inter-annual changes of EHE, the session distribution of EHE and their responses to climate change were analyzed in the study area. The results showed that the EHE in the region was extremely unstable. The inner-annual distribution was uneven and the concentration degree was higher. The extreme flood events mainly occurred in July, and the extreme low water events mainly appeared in February. The inter-annual variability was quite unstable with a high deviation from the normal distribution. The extreme flood events totally presented an increasing trend and had an abrupt change in 1986; while the extreme low water events totally presented a decreasing trend and had an abrupt change in 1993.The extreme flood frequency had a higher correlation with precipitation, while the extreme low water frequency had a higher negative correlation with temperature.