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黄土高原地区坡面土壤侵蚀具有明显的垂直分带性,溅蚀片蚀带是坡面侵蚀的最上方地带,研究片蚀过程含沙量变化有助于阐明坡面侵蚀规律。本文采用人工模拟降雨试验方法研究了黄土坡面片蚀稳定含沙量及其影响因素;试验处理包括2种质地的黄土(塿土和黑垆土),2个雨强(90和120 mm/h)和4个坡度(10°、15°、20°和25°)。结果表明:在不同质地黄土、降雨强度和坡度条件下,水流含沙量均呈现先减小后平稳的规律;稳定含沙量与土壤颗粒体积分形维数、降雨强度和坡度呈幂函数关系,稳定含沙量随土壤颗粒体积分形维数的增大而减小,随降雨强度和坡度的增大而增大,影响程度依次为土壤颗粒体积分形维数、降雨强度和坡度;所分析的水动力学指标中单位水流功率与稳定含沙量关系最密切,降雨强度对稳定含沙量的影响大于单位水流功率。
Soil erosion on the slope of the Loess Plateau is obviously vertical zonation. The erosion zone is the topmost area of slope erosion. Studying the change of sediment concentration in the process of erosion will help to elucidate the slope erosion law. In this paper, artificial rainfall test was used to study the stable sediment concentration and its influencing factors of loess slope erosion. Two types of loess (loam and black soil), two rainfall intensities (90 and 120 mm / h) and 4 slopes (10 °, 15 °, 20 ° and 25 °). The results show that under the condition of loess, rainfall intensity and slope gradient, the sediment concentration of the water flow decreases first and then decreases steadily. The stable sediment concentration has a power function relationship with the volume fractal dimension of soil particles, rainfall intensity and slope gradient, The stable sediment concentration decreases with the increase of the fractal dimension of soil particles, and increases with the increase of rainfall intensity and slope degree. The influence degree is followed by the volume fractal dimension of soil particles, rainfall intensity and slope. The analyzed water Kinetic indicators in the unit of water power and stable sediment concentration is most closely related to the impact of rainfall intensity on the sediment concentration greater than the unit of water power.