相似性降水条件下北洛河水沙变化特征

降水是河流径流来源也是水土流失的主要动力,通过选择相似降水年组比较河流水沙变化,可以更好揭示土地利用变化对河流水沙变化的影响。采用1954年到1996年北洛河状头水文站实测资料,根据年份差大于5年,年雨量差小于20 mm和汛期雨量差小于10 mm等三个指标确定了8个相似降水年组。通过比较相似性降水年组径流量和输沙量变化,分析了不同时间河流水沙变化特点;并通过组间比较初步探讨了北洛河水沙变化趋势。分析表明,与1980年相比,1996年除汛期径流量增加外,年径流量,年与汛期的输沙量和含沙量均增加;在其他时段,输沙量在1970年代后期以前呈减少趋势,年径流量和汛期径流量有增加趋势,而年均和汛期含沙量均有减少趋势。

The impact evaluation of land use change on runoff and sediment change are analyzed based on the paired-year with similar precipitation that was the major sources of runoff and the power of soil and water erosion.The 8 paired-years with similar precipitation from the observed data of Zhuangtou Hydrology Station of the Beiluo River from 1954 to 1996 are selected according to three criterions as the difference of year over 5 years,the difference of annual precipitation less than 20 mm and in flood season the ...