【摘要】 针对主成分分析法能解决多因素影响的优点,分别介绍了主成分分析法的原理和算法,并将其运用到流域水循环效应综合评价中.在年尺度下,选择降雨、输沙和径流作为析因变量,借助SPSS软件包进行析因研究,以黄河清涧河流域为例,确定各因素在水循环效应中的贡献率.结果表明:人类活动对流域“二元水循环”的驱动力活跃,对于减水、减沙的贡献率分别达到97.7%和92.0%,且时间尺度越大这种水循环效应表现得越明显.可以认为,在全球气候变化背景下,人类活动因子是清涧河流域水循环的主要驱动因子,降雨因子的作用不显著.更多还原

【Abstract】 In light of the merits of principal component analysis in solving the influence of multifactor,the principle and Algorithm of this method are introduced in detail;and then performing this integrated evaluation technique on hydrological cycle effect in river basin.Selecting precipitation,sand transport and runoff as separate variables under the scale of year,the hydrological cycle evolvement is!analyzed in virtue of SPSS.After that,taking the Qingjian River basin for example,the contributivenesses of different ingredients on total effect are calculated.The result indicates that human activity is the most active driving forces to duality hydrological cycle.The contributiveness to water and sand evolvement can up to 97.7% and 92.0%;this trend is more prominent under larger time scale.So the conclusion is drawn that under the variational climate background,the dominant driving force of the hydrological cycle is human activity;and the action of rainfall is not notable.更多还原