【摘要】 以黄河清涧河流域为例,首先在10年尺度下对流域水沙因子进行分离,采用中间差分格式估算水沙演变各项因子的年代影响量,确定主成分.然后在年尺度下,以这些主成分为析因变量,借助SPSS软件进行因素分析,准确给出各主成分在流域水循环效应的贡献率.结果表明,人类活动对流域减水、减沙的贡献率分别为97.7%和92.0%,是水沙演化的主导因素,且时间尺度越大这种趋势表现得越明显.更多还原

【Abstract】 Taking the Qingjian River basin for example,the water and sand factors of basin under ten years scale are separated first.Then the decade affections of all factors are estimated using center difference and ascertains principal components.Selecting precipitation,sand transport and runoff as separate variables under the scale of year,and then the hydrological cycle evolvement is analyzed in virtue of SPSS.The contributes of different ingredients on total effect are calculated.The result indicates that,human activities contribute to 97.7% and 92.0% of water and sand evolvement.The interferences of human activities are the dominant factors;and this trend is more prominent under larger time scale.更多还原