开都河源区径流变化的气候响应

气候变化下的山区径流时空变异特征是干旱区水文水资源研究的热点之一。本研究选择天山南坡开都河流域源区为典型研究区,基于1958-2017年大山口水文站和巴音布鲁克水文站径流数据,及巴音布鲁克气象观测数据,采用TFPW-MK趋势检验、小波分析与小波相干等方法分析径流序列的趋势、突变和周期特征及其对气候变化的响应。结果表明:近60 a来,开都河源区径流、降水、气温呈显著增加趋势,并且径流量、降水量与最高气温的增率在加快,而平均气温与最低气温的增率减缓;径流量、降水与平均气温的突变年份集中在20世纪90年代,并且均存在28 a的周期;夏季径流量增加主要受夏季升温的影响,而早春径流量增加主要与冬季降水增加、早春升温有关;在年尺度上,降水是影响开都河径流变化的主要因素,气温主要以积温形式影响着径流的变化;在月尺度上,积温与降水均与径流呈显著正相关关系,且源区上游径流较下游径流对气温变化更为敏感。

Climate response of runoff variation in the source area of the Kaidu River

Temporal and spatial variability of runoff in inland rivers and mountainous areas under climate change is a major focus in the study of hydrology and water resources in arid areas.The source area of the Kaidu River basin on the south slope of Tianshan mountain was selected as the study area.Based on 1958-2017 Dashankou hydrological station data,Bayanbulak hydrological station data,and Bayanbulak meteorological observation data,the trends,catastrophe,wavelet analysis and coherence,and response to climate changes of Kaidu River long-sequence runoff were studied using the TFPW-MK trend test,wavelet analysis,and other methods.The results show that for nearly 60 years,the runoff,rainfall,and temperature elements of the Kaidu River showed a significant trend,the abrupt years was concentrated in the 1990s,and the increasing rate of runoff,rainfall,and maximum temperature was accelerated,whereas the increasing rate of the average and minimum temperature was slowed.The annual average runoff,annual cumulative rainfall,and annual average temperature had a period of 28 year.The increasing summer runoff was mainly affected by the summer high temperature,whereas the increasing winter and early spring runoffs were mainly related to increasing rainfall during the winters and increased temperatures during early springs,respectively.On the annual scale,precipitation is the main factor impacting runoff change;temperature mainly affected runoff change in the form of accumulated temperature.On the monthly scale,both temperature and rainfall had significant and positive correlations with runoff.Upstream runoff was more sensitive to temperature change as compared with the downstream runoff.