岷江上游近59年径流变化及归因识别

Runoff Changes and Attribution Identification in the Upper Reaches of Minjiangg River in Recent 59 Years

为高效利用岷江上游流域的水资源,基于1960~2018年流域水文气象资料,采用多种统计学理论分析径流的趋势、周期和突变点,应用基于Budyko理论的弹性系数法(Choudhury-Yang公式)和累积量斜率变化率比较法(SCRCQ法)对径流变化进行归因分析。结果表明,径流以12.5mm/10a的速率呈显著减少趋势,并在1993年发生突变。径流变化存在3、8、12、18年的主周期,其年内分配不均,主要集中于夏秋两季,占比73.6%。降雨对径流变化最为敏感,下垫面参数次之,潜在蒸散发最不敏感。Choudhury-Yang公式和SCRCQ法计算出气候变化对径流减少的贡献率分别达到58.13%、63.29%,表明气候变化是研究区径流减少的主要因素,而人类活动对径流减少的贡献亦不容低估,贡献率分别达到41.87%、36.71%。

In order to efficiently utilize water resources in the upper reaches of the Minjiang River Basin,based on hydro-meteorological data of the basin from 1960 to 2018,a variety of statistical theories were used to analyze the trend,cycle and abrupt point of runoff.The elastic coefficient method based on Budyko theory(Choudhury-Yang formula)and the comparative method of cumulated slope change rate(SCRCQ method)were used to analyze the attribution of runoff changes.The results show that the runoff decreases significantly at a rate of 12.5 mm/10a,and a sudden change occurred in 1993.There are 3 years,8 years,12 years and 18 years main cycles of runoff change,and the annual distribution is uneven,mainly concentrated in summer and autumn,accounting for 73.6%.Rainfall is the most sensitive to runoff,followed by underlying surface parameters,and potential evapotranspiration is the least sensitive.Choudhury-Yang formula and SCRCQ method calculated that the contribution rate of climate change to runoff reduction was 58.13% and 63.29%,respectively.Climate change was the main factor of runoff reduction in the study area,and the contribution rate of human activities to runoff reduction should not be underestimated,reaching 41.87% and 36.71%,respectively.