1950年以来黄河头道拐站开河日期变化特征

摘要

The paper studied the characteristics of break-up date in the Toudaoguai Hydrological Station of the Yellow River by the K-Means cluster algorithm and the Mann-Kendall examination methods according to the measured ice data since 1950. The results show that:a)the break-up date in the station has the trend in advance,which is more prominent after 2000;b)the break-up dates since 1950 can be sorted 3 classes by March 16th and March 24th,which are earlier break-up,common break-up,and later break-up,and the earlier break-up years increased rapidly;c)from 1988 to 1995 can be used as the transitional period of the break-up date changed from later to earlier,and the year of 1992 is the mutational point;d)the temperature is the main influencing factor of the break-up date,the trend in advance of the break-up date keep consist-ent pace with the temperature warming in the area after 1988.%根据1950年以来的实测冰情数据，应用K－Means聚类算法和Mann－Kendall法研究黄河头道拐水文站开河日期的变化特征。分析结果表明：①头道拐站开河日期具有逐渐提前的趋势，2000年后提前趋势明显；②以每年3月16日、24日为界，开河日期可分为“早开河”、“正常开河”与“晚开河”三类，1990年以来“早开河”的年份明显增多；③1988—1995年可作为头道拐站开河日期早晚变化的过渡期，1988年之前以晚开河为主，1995年之后则早开河的年份显著增多，1992年为开河日期由晚向早变化的突变点；④气温为影响开河早晚的主要因素，头道拐站开河日期的提前与1988年之后区域气温回暖的趋势基本一致。