变化环境下塔里木河径流变化及其影响因素分析

通过对塔里木河近50 a的年径流资料进行分析,得到变化环境下流域径流演变趋势,并从气候变化和人类活动两方面分因子探讨了其对径流变化过程的影响.研究结果表明,近50 a来塔里木河的径流过程发生了显著变化.源流出山口年径流量总体上呈增长趋势,特别是20世纪90年代以后,各源流普遍进入丰水期,但河流在出山口后,年径流量减少的趋势却趋于明显,且沿程递减幅度增大.从影响因素看,以气温上升和降水增加为特征的气候变化是源流径流量总体增长的主要影响因素,其中气温变化对流域蒸发的影响并不显著,但气温升高使冰川融水径流补给增长明显;降水增加对各源流径流变化的影响存在差异,可能与径流的补给类型有关.从流域整体看,人类活动是造成流域径流变化的主导性因素.水利工程的修建和水资源取用量增加极大地改变了流域的径流过程,塔里木河流域综合治理工程的实施对流域径流恢复产生了积极的正面影响.

Runoff Change and Its Influencing Factors Under Changing Environment in Tarim River

Through the analysis of nearly 50 year annual runoff data of Tarim River,the evolution trend of runoff under changing environment is investigated. Possible impacts on the runoff process are discussed in the two aspects of climate change and human activities. Results show that under changing environment,the runoff process of Tarim River in nearly 50 years has been significantly changed. Under the influence of climate change characterized by temperature rising and precipitation increasing,runoff in headstream zone of Tarim River generally has an obvious increasing tendency. Temperature variation has little effect on regional evapotranspiration,but increases glacial meltwater runoff. There are some differences in the effect of precipitation increasing runoff among different headstream zones of Tarim River. However,human activities are the dominant influencing factor to runoff changes. The construction of hydraulic engineering and the increased amount of water use have significantly changed the runoff process of Tarim River and comprehensive management engineering of Tarim River has positive effects on the whole basin.