潘成忠, 马岚, 上官周平. 含沙量对草地坡面径流泥沙沉积和水力特性的影响[J]. 水科学进展, 2008, 19(6): 857-862.
引用本文: 潘成忠, 马岚, 上官周平. 含沙量对草地坡面径流泥沙沉积和水力特性的影响[J]. 水科学进展, 2008, 19(6): 857-862.
PAN Cheng-zhong, MA Lan, SHANGGUAN Zhou-ping. Influence of sediment concentration on deposition of silt and runoff hydraulics on grassland[J]. Advances in Water Science, 2008, 19(6): 857-862.
Citation: PAN Cheng-zhong, MA Lan, SHANGGUAN Zhou-ping. Influence of sediment concentration on deposition of silt and runoff hydraulics on grassland[J]. Advances in Water Science, 2008, 19(6): 857-862.

含沙量对草地坡面径流泥沙沉积和水力特性的影响

Influence of sediment concentration on deposition of silt and runoff hydraulics on grassland

  • 摘要: 通过室内模拟试验,在坡度为3°和9°、流量为20和60L/min条件下研究了不同浓度(0~350kg/m3)含沙水流流经草地的泥沙沉积过程及其水力学特性。结果表明,坡面泥沙沉积量随含沙量的增加而增大,3°时泥沙沉积率与含沙量呈正相关,而9°时沉积率与含沙量呈反势。坡度对泥沙沉积影响显著,而在相同坡度条件下,两种流量试验的泥沙沉积量无明显差异。相同坡面坡上部位流速小于坡下部位,且含沙量对坡面流速影响较小。在相同坡度和流量条件下,水流雷诺数随含沙量的增大而减小。3°时水流阻力系数和曼宁糙率均随含沙量的增加而增大,而9°时含沙量对阻力影响不明显,因此在土壤侵蚀较严重地区进行坡面水文过程演算时需考虑含沙量对缓坡糙率的影响。

     

    Abstract: In order to reveal the performance of grass strips on silt-laden flow with high sediment concentration, the experiments were carried out on different sediment concentration of 0-350 kg/m3 in grassplots on the slope of 3° and 9° and discharge of 20 and 60 L/min, and the deposition of sediment and hydraulic characteristics of runoff were analyzed.The results show that the sediment mass deposited on grassplots increase with the concentration.There is a positive relationship between the deposition rate and the sediment concentration at 3°, but a negative relationship at 9°.Under the experimental conditions, the discharge plays a negligible role in the total mass of sediment deposition, but slope significantly affects the sediment deposition.The flow velocities at downslope are greater than that at upslope, and the sediment concentration has a minor influence on the velocity.On the same slope and discharge, the Reynolds number of silt laden flow decreases with the increase of sediment concentration Runoff resistance coeff icient (f) and Manning roughness (n) increase with sediment concentration at 3°, but there is no significant correlation between them at 9°.Therefore, sediment concentration should be considered in the estimation of hydrological processes in the region with severe soil erosion.

     

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