黄土高原区高含沙水流发生频率空间分异及其影响因素

以1964-1989年黄土高原区284个水文站的泥沙观测资料为基础,结合相应区域内自然条件与人类活动相关资料,运用空间分析及数理统计方法,研究了黄土高原区高含沙水流发生频率的空间分布规律,并分析了高含沙水流发生频率及其与各影响因素之间的关系。研究结果表明,黄土高原区高含沙水流发生频率高值区为带状分布,呈东北-西南向,且存在3个高值中心区,分别位于111°E、40°N,107°E、36°N和104°E、34°N附近;在分析各影响因素与高含沙水流发生频率关系基础上,进一步研究了多因素对高含沙水流发生频率的综合影响,结果表明,灌木林、丘陵旱地、有林地、黄土厚度、年平均降水量等主要影响因素对高含沙水流发生频率的相对贡献率依次为17%、4%、7%、30%、42%。

Study of the spatial differentiation of hyperconcentrated flows frequency in the Loess Plateau

Based on the data from the Yellow River and its tributaries in the Loess Plateau,a study of the spatial differentia tion of hyperconcentrated flows frequency is made,also the relation between hyperconcentrated flows frequency and influencing factors is analyzed The results show that the high-frequency zone of hyperconcentrated flows shows itself a shape of strip,with the northeast southwest direction There are three high-frequency centers in the strip They are at lat itude 40°N,36°N and 34° N.It seems that different factos have different effecs to cause the hyperconcentrated flows The result of the multiple-factor regression analysis shows that the efficiency of shrub,dry-land fields in hilly,woodland,loess thickness and mean annual pre cipitation to the hyperconcentrated flows are 16.6%,4.4%,6.5%,29.7% and 42.8%,respectively.