气候变化对塔里木河来自天山的地表径流影响

Impact of Climate Change on Surface Runoff of Tarim River Originating from the South Slopes of the Tianshan Mountains

塔里木河水资源主要来自天山南坡两条源流,选择西段阿克苏河和中段开都河-孔雀河作为研究区.1956—2003年研究河源山区气温呈持续升温且降水波动增加的趋势,其中1995—2003年升温强劲,升温速率高出48 a期间平均的3倍以上;降水自1986年后持续增加,20世纪90年代较80年代增幅达18%,并显示出河源山区湿岛向塔里木盆地扩展.因高山缺少气象观测,出山径流过程变化可以综合反映中高山带的气候变化.塔里木河来自天山的地表径流在1986—2003年间持续增长,以冰川融水补给为主的库玛拉克河,1994年以来年径流量增加已在前期平均值基础上提升了一个台阶;开都河以降水径流补给为主,1986—2002年出现了观测记录以来的丰水期,并使1986年后博斯腾湖水位快速上升,恢复到1958年记录的最高水位以上.两河年径流变化趋势基本相似,但也显示有西、中段的气候变化局部差异,出现丰枯水期的不一致;然而,在近16 a升温过程中,年径流增长幅度和快慢相近.

At present, the main water resources of Tarim River come from two source rivers on the south slopes of the Tianshan Mountains. Aksu River and Kaidu River-Kongque River were selected as the study regions in the paper. Based on durative rising tendency of temperature and fluctuant increasing tendency of precipitation in the intermediate areas from 1956 to 2003, it is found that the temperature was climbing intensively from 1995 to 2003 with a temperature increasing rate higher than 3 times as compared with the average over the 48 years, and the precipitation has also continually increased since 1986. The average annual precipitation during the 1990＇s was 18% more than that during the 1980＇ s, even reaching 21.4% at the western Tianshan Mountains. Moreover, a wet island expanding to the Tarim basin can be seem in the isoline maps of annual precipitation from 1986 to 2000. The annual mountainous runoff can be thought as the process of climate change in the intermediate and high mountainous zones synthetically in the case of less meteorological data in the high mountains. The surface runoff from the headwaters of Tarim River originating from the south slopes of the Tianshan Mountains was continually increasing during 1986 - 2003. In the Kumarik River, a river mainly supplied by glacier meltwater （about 70%）, the annual runoff has increased distinctly since 1994. In the Kaidu River, a river mainly supplied by precipitation （about 80%）, a high water period in the instrumental observation records took place during 1986-2002, as a result, the water level of Bosten Lake rapidly rose after 1986 and reached the highest in the record since 1958. The changing tendencies of annual runoff in the two rivers are basically similar. However, the climate changes have a local difference between the western section and the eastern section, with a disagreement in the high water and low water periods. In addition, the range and rate of annual runoff increasing are similar in the temperature rising process in the last 16 years.