黑河流量和祁连山气候的年代际变化

Study on Interdecadal Change of Heihe Runoff and Qilian Mountain' s Climate

利用黑河上游莺落峡水文站流量资料和选自祁连山区2280～3360m高度处的7个气象观测站平均的历年各月标准化降水量、气温序列,分析了1944—2000年期间黑河流量与祁连山区自然气候的年代际变化。结果表明:20世纪80年代的流量是过去57年中最大的10年,90年代有所减小,但主要表现在夏、秋季,而冬、春季仍然保持高流量。祁连山区气候演变存在非常明显的季节变化、年际变化和年代际变化。自70年代以来,除夏季降水量呈上升趋势外,秋、冬、春三季均表现出明显的变干,尤其是秋、冬两季;自80年代以来,祁连山区气候明显变暖,各季气温显著升高,尤以秋、冬两季升温最快,这可能是冬季黑河流量显著增加,祁连山雪线上升的主要原因。综合分析表明,黑河流量的增加取决于两个方面:一是夏季降水量的增加,二是冬季气候的明显变暖。

The interdecadal variety have been analyzed by using Yingluoxia hydrology station runoff data(1944～2000) of Heihe upper stream with the average monthly standardized precipitation and air temperature data of 7 weather observation stations located on the Qilian mountain area from 2240 to 3361 m high place. The results show that the runoff in 1980′s is the biggest 10 years in past 57 years, 1990′s tend to decrease, but primarily appearing from summer to autumn, and yet still keeping the high runoff from winter to spring. The Qilian Mountain′s climate evolution significantly exists the season change, the interannual change and interdecadal variety. Since 1970′s, besides the summer with precipitation increasing, all the three quarters of autumn, winter and spring have obviously change to drought, and particularly for autumn and winter; Since 1980′s, the climate is warming obviously in Qilian mountain area, air temperature of each season remarkably go up, particularly for the autumn and winter, this may be the main reason for Heihe river′s runoff increasing and Qilian mountain′s snow line rising. The synthesized analysis shows that the increase of Heihe river′s runoff is decided by two aspects: The first is summer precipitation increasing, second is the obviously climate warming in the winter.