晋西黄绵土坡面径流流态与输沙特征试验研究

Characteristics of flow pattern and sediment transport processes on loessal soil slope in western Shanxi Province

为了探讨晋西黄绵土坡面径流流态与输沙特征,本研究采用室内人工模拟降雨试验方法,对降雨条件下坡长对该区坡面径流雷诺数、弗劳德数、径流量、产沙量与输沙率进行量测与分析。结果表明:在雨强30~125mm/h、坡长1~5m的情况下,坡面薄层径流为层流,且为急流;径流流态对坡面水流侵蚀力有显著影响,产沙量与雷诺数呈良好幂函数关系;雨强与坡长的增大可增强径流紊动性,输沙率随二者的增大呈增加趋势,当雨强大于60 mm/h、坡长由3 m延长到4 m时,输沙率增量较2~3 m与4~5 m时小;输沙率与径流量的关系可用幂函数描述。该研究结论能够为黄土陡坡面水土流失治理和水土保持措施的布设提供一定的依据。

In order to investigate the characteristics of flow pattern and sediment transport processes onloessal soil slope, western Shanxi province, Reynolds number, Froude number, runoff volume, sedimentyield and sediment transport rate under different rainfall intensities and slope lengths were measured and an-alyzed based on the laboratory simulated rainfall events. The results indicate that flow pattern is basicallylaminar flow and torrential flow on slope lengths 1-5 m under 30-125 mm/h rainfall intensities. The flowpattern has significant impact on runoff erosivity, and there is a good power function relationship betweensediment yield and the Reynolds number. Runoff turbulence is stronger with increasing rainfall intensity andslope length,and the sediment transport rate increases with these two factors. However,increment of sedi-ment transport rate with slope length extending from 3 m to 4 m are less than that from 2 m to 3 m and4 m to 5 m when rainfall intensity greater than 60 mm/h. The relationship between sediment transport rateand runoff volume can be described using power function. The conclusions can provide scientific basis forthe control of soil and water loss as well as the construction of soil and water conservation measures on loess plateau slope.