气候变化下石羊河流域上游产流区的径流响应研究

Response of runoff to climate change in upstream generation area of Shiyang River basin

【目的】分析西北典型干旱区石羊河流域上游产流区径流对未来气候变化的响应,为石羊河流域未来水资源的规划利用提供参考。【方法】应用可变下渗能力模型(VIC)模拟水文过程,基于模型参数率定,利用统计降尺度模型(SDSM)对全球气候模式(GCMs)中HadCM3模式下A2、B2情景进行降尺度处理,分析A2、B2情景下石羊河流域上游产流区气候要素的变化,以预估的未来气候情景数据作为验证后VIC模型的输入,分析未来气候变化下石羊河流域的水文响应。【结果】VIC模型的效率系数在率定期(1990-1994年)和检验期(1995-1996年)分别为0.769和0.690,相关系数分别为0.955和0.894,表明VIC模型能够较好地描述流域大尺度水文过程;在未来2020s(2010-2039年)和2050s(2040-2069年),研究区多年平均最高气温在A2情景下分别较现状升高1.3和2.8℃,B2情景下分别较现状升高1.3和2.5℃;在2个时期的2种气候情景下,多年平均最低气温均升高0.1℃左右;在A2情景下2020s和2050s多年平均降水量分别较现状减少7.6%和15.2%,B2情景下2个年代的多年平均降水量分别减少8.7%和13.1%;2020s多年平均径流量在A2和B2情景下分别较现状减少2.8%和1.4%,2050s多年平均径流量在A2和B2情景下分别减少13.2%和8.3%。【结论】石羊河流域径流在未来A2、B2气候模式下的不同时期内均会呈减少趋势。

【Objective】The response of runoff to future climate change was analyzed in the upstream generation area of Shiyang River basin,which is a typical arid basin in northwest China,to provide information for future planning and utilization of water resources in the basin.【Method】Variable infiltration capacity（VIC）model was applied to simulate the hydrological cycle in this basin.Based on parameters calibration,projected climate data under A2 and B2scenarios produced with HadCM3 of global climate models（GCMs）was downscaled using statistical downscaling model（SDSM）.Different meteorological elements from A2 and B2scenarios were analyzed in the upstream generation area of Shiyang River basin,and the projected scenarios were chosen as the input data for verified VIC model to simulate the influence of future climate change on runoff,to analyze the response of runoff to futrue climate change in Shiyang River basin.【Result】The hydrological cycle in Shiyang River basin was well described by VIC model with efficiency coefficients of 0.769 and 0.690 and correlation coefficients of 0.955 and 0.894 in calibration and verifica-tion periods,respectively.Average maximum temperatures in 2020 sand 2050sunder A2 scenario were 1.3and 2.8 ℃ higher than current status,and the temperatures would rise by 1.3 ℃ and 2.5 ℃in these two periods under B2 scenario.Average minimum temperatures would rise by about 0.1 ℃in the two periods under either A2 or B2.Precipitation would reduce by 7.6% and 15.2%in the 2020 sand 2050sunder A2 scenario compared to current status,and reduce by 8.7% and 13.1% under B2 scenario.Runoff would decrease by 2.8% and 1.4%in 2020 sunder A2and B2 scenarios and by 13.2%and 8.3%in 2050 sunder A2and B2 scenarios,respectively.【Conclusion】The runoff in Shiyang River basin would reduce in different future periods under A2 and B2scenarios.