黄河兰州站天然径流量变化及其计算方法探讨

根据黄河兰州站1934年以来天然径流量资料,分析了天然径流量的阶段性和周期性变化规律,探讨了天然径流量计算方法和现有数据的可信情况。结果表明:(1)天然径流量的年、汛期和非汛期变化趋势基本一致,且有前期和中期偏多,近期偏少特点。(2)近70年天然径流量的变化经历了各3个丰、枯水段,而且存在较明显的准3年周期,同时还显示出不同时段的主要周期存在一定差异的特点。(3)现有天然径流量量值较实际值偏小,其原因可能与还原计算值不够全面和尚未考虑气候影响因素等有关。

Discuss on the natural runoff change and Its calculation method at the Lanzhou station of Yellow River

According to the observed natural runoff data of Lanzhou station since 1934,the phase and periodicity of runoff change are analyzed,the calculation method of the natural runoff and credible situation of current period data are researched.The results have showed that the variation trend of early natural runoff in flood season and non-flood season were consistent,and the runoff in pro-and mid-phases were more,in recent phase was less.The variations of annual natural runoff in recent 70 years have undergone three rich and dry phases respectively,also there were distinct qusi-three-year periodicity.At the same time the main periodicity in different period still existed some difference.The calculated runoff values were less than the real values,the reasons might be that the revival value was not overall and the climate factor was not considered.