基于Budyko假设的乌伦古河源区径流变化特征及归因识别

Characteristics and Attribution Identification of Runoff Variation in the Source Area of Ulungur River Based on the Budyko Hypothesis

揭示流域径流演变特征及定量识别驱动因素贡献率对流域水资源适应性管理和水安全保障至关重要。基于乌伦古河源区二台水文站1960~2015年实测逐月径流序列及同期气象和人类水土资源开发利用影像数据,采用滑动移除小波分析法、Mann-Kendall趋势检验法、滑动t检验法等方法分析水文气象要素序列演变趋势及突变特征,基于Budyko假设的弹性系数法定量识别气候变化与人类活动对研究区径流变化的贡献率。结果表明,乌伦古河源区径流序列呈不显著上升趋势,降水序列呈显著上升趋势,潜在蒸散发序列呈显著下降趋势;径流序列于1995年发生突变,相较于基准期1960~1994年,变化期1995~2015年径流对降水、潜在蒸散发及下垫面特征参数的敏感性系数分别增加了8.8%、25.0%、7.8%;降水与潜在蒸散发、下垫面特征参数变化对径流变化的贡献率分别为39.2%、7.0%、53.8%,研究区径流变化由人类活动与气候要素共同驱动,人类活动为主要驱动因素。

Revealing the characteristics of basin runoff evolution and quantitatively identifying the contribution of driving factors is essential for adaptive water resources management and water security in basins.Based on the measured monthly runoff series from 1960-2015 at the NO.2 hydrological station in the source area of the Ulungur River and the meteorological and human water and soil resources development and utilization image data for the same period,the sliding removal wavelet analysis method,the Mann-Kendall trend test method and the sliding t test method were used to analyze the evolution trend and mutation characteristics of the hydrometeorological elements sequence.The elastic coefficient method based on the Budyko hypothesis was used to identify the contribution rates of climate changes and human activities to runoff change in the study area.The results show that there is a non-significant upward trend in runoff series,a significant upward trend in precipitation series and a significant downward trend in potential evapotranspiration series in the Ulungur River source area;The runoff series changed abruptly in 1995,with the sensitivity coefficients of runoff to precipitation,potential evapotranspiration and subsurface characteristics increasing by 8.8%,25.0%and 7.8%respectively in the change period 1995-2015 compared to the base period 1960-1994;The contribution of changes in precipitation and potential evapotranspiration and subsurface characteristics parameters to runoff changes are 39.2%,7.0%and 53.8%respectively.The runoff changes in the study area are driven by a combination of human activities and climatic elements,with human activities being the main driving factors.