中文摘要：

利用1960-2014年石羊河流域5个气象站逐日结冰资料,运用线性趋势系数法、Morlet小波分析法、累计距平和信噪比法以及相关系数法,分析了石羊河流域结冰日的时空分布及极值变化特征以及结冰日数与大气环流特征量的关系。结果表明：受海拔高度、地形地貌和植被覆盖的影响,石羊河流域结冰日数具有明显的地域特征,结冰日数从北向南逐渐增多（除凉州外）,南部山区天祝结冰日数远多于其他各地,占年总日数60.5%。年、年代结冰日数总体呈减少趋势,民勤和凉州的减少趋势尤为显著,递减率分别为-4.458 d·（10a）^-1、-3.300 d·（10a）^-1。结冰主要出现在11月至次年3月,12月和1月每天都有结冰出现。年结冰初日总体呈推迟趋势,年结冰终日总体呈提前趋势（除古浪外）,各地结冰初、终日有一定的差异,最早结冰初日（2003年8月15日）、最迟结冰终日（1986年6月26日）均出现在天祝。各地结冰期也有一定的差异,结冰期最长在天祝（307 d）,结冰期最短在凉州（162 d）。年结冰日数的时间序列存在着6 a和8-9 a的准周期变化,民勤和凉州的年结冰日数发生了突变,突变的年份均在1995年,永昌、古浪和天祝的年结冰日数没有发生突变。石羊河流域结冰日数与亚洲区和北半球极涡面积指数、强度指数以及冷空气等环流特征量呈显著正相关,与西藏高原和东亚槽强度等环流特征量呈显著负相关。分析总结了石羊河流域结冰日的变化规律以及与大气环流特征量相关关系,可为水利、电力、交通、建筑等项目设计、防灾减灾、区域经济发展提供科学依据,同时可为流域气候变化的研究和结冰的预报预测提供参考。

英文摘要：

Based on daily ice data of five meteorological stations in Shiyang River Basin,Gansu Province,China during 1960-2014,this paper analyzed the temporal and spatial distribution and extreme changes characteristics of ice days,and the relationship between ice days and atmospheric circulation by using linear trend coefficient method,Morlet wavelet analysis method,accumulative anomaly,signal-to-noise ratio method and correlation coefficient method. Results show that： spatial distribution of ice days in Shiyang River Basin was regionally obvious due to the altitude,topography and vegetation cover;ice days overall increased gradually from north to south（except Liangzhou）,with the most appeared in Tianzhu（220.8 d）of southern mountains area,accounting for 60.5% of the annual total days,and the least appeared in Liangzhou（155.8 d）of oasis plain area,accounting for 42.7% of the annual total days. Annual and decadal changes of ice days all appeared decreasing trends,and were the most significant in Minqin and Liangzhou with decreasing rates being-4.458 d·（10 a）^-1and-3.300 d·（10 a）^-1,respectively. Ice days occurred mainly from Nov. to Mar. next year,accounting for 68.7% to 91.4% of the annual ice days,and ice appeared every day in Dec. and Jan.. Ice starting date overall had a delay trend,and ice ending date had an advanced trend（except Gulang）. Ice starting and ending date differed in places,with the earliest ice first date appeared in Tianzhu（August 15,2003）,the latest ice first date appeared in Liangzhou（November 1,2009）,the earliest ice ending date appeared in Minqin（April 9,1969）,and the latest ice ending date appeared in Tianzhu（June 26,1986）. Ice periods also differed in places,with the average ice periods ranging from 189.4 to 264.2 d,the longest ice period appeared in Tianzhu（307 d）,and the shortest ice period appeared in Liangzhou（162 d）. Time series of annual ice days had 6 years and 8-9 years quasi-periodic variation. Annual ice days in Minqin and Liangzhou both