气温变化和水库运行对黄河内蒙古段凌情的影响

Influence of Temperature Change and Reservoir Operation on Ice Jam Floods in Inner Mongolia Reach of Yellow River

近半个世纪内,气温变化和水库运行使黄河内蒙古段凌情呈现出不同的特点。基于黄河内蒙古段1959-2013年冬季气温及水文资料,统计分析了巴彦高勒、三湖河口、头道拐3个水文站近55年平均气温及其变化过程,并结合水库冰期控流情况,分时段研究了黄河内蒙古段凌情变化。结果表明,1968年水库运行后至1987年气温突变前,封河与开河日期比基准期均推后,封冻持续时间基本不变;1987年气温突变后,封冻日期推后,开河日期提前,封冻期缩短;流凌日期、封河日期与气温转负后的降温强度有关;累积负气温与冰厚呈显著负相关,相关系数达-0.817,气温升高使得首封位置下移。

In the past half century,owing to reservoir operation and temperature change,the ice jam floods in Inner Mongolia reach of the Yellow River appear different characteristics.According to the meteorological and hydrological data observed from 1959 to 2013,we selected the Bayangaole,Sanhu-hekou,Toudaoguai hydrological stations as the sampling points,and analyzed the average air temperature and its changes in the last 55 years.Combined with the situation of reservoir regulation and storage during ice season,the change of ice jam floods in Inner Mongolia reach of the Yellow River are studied.The results show that from 1968（reservoir staring to operation）to 1987（abrupt change of temperature）,the frozen and breakup date were obviously delayed,but the frozen duration was basically unchanged;after climate changed suddenly in 1987,the frozen date was delayed and the breakup was moved up,and the frozen duration became shorter;the dates of frozen and ice-run changed with the air temperature decreasing;the cumulative negative temperature and ice thickness had significant negative correlation,and the correlation coefficient was-0.817;the first frozen position moved to the downstream with the temperature increasing.