论文部分内容阅读
为了明确细沟发育特征及对坡面产流产沙的作用,该文在固定坡度(10°)和2个雨强(1.5和2mm/min)条件下,采用室内纯净水模拟降雨试验的方法,研究了塿土和黄绵土的坡面细沟发育过程和水沙关系。研究结果表明,细沟主要由沿坡面方向呈线状平行分布的跌坎链相互连通演化而成,在雨强较小时塿土更易形成细沟,而黄绵土在雨强较大时才能形成细沟。含沙量与侵蚀速率的变化规律与坡面跌坎和细沟的形成具有同步关系,雨强的增大不会引起塿土含沙量和侵蚀速率的明显增加,但对黄绵土含沙量和侵蚀速率的变化有很大影响,在大雨强时黄绵土含沙量和侵蚀速率会迅速增加,并在坡面细沟形成后很快超过塿土。同时,细沟的存在并不会引起塿土含沙量和侵蚀速率的明显变化,但黄绵土对坡面细沟反应敏感,细沟一旦形成会导致其含沙量和侵蚀量的急剧增加。该研究为坡耕地细沟侵蚀的有效防治提供相应的理论指导。
In order to clarify the characteristics of rill development and its effect on runoff and sediment production on the slope, the indoor pure water simulating rainfall test was used under the condition of fixed slope (10 °) and two rainfall intensities (1.5 and 2 mm / min) The relationship between waterlogging and the development process of silt and loessial soil was studied. The results show that the rill is mainly formed by the interconnection and evolution of the chain banks distributed linearly parallel to the slope direction. When the rainfall intensity is small, the rill is more likely to form the rill, while the loessial soil forms thinner when the rainfall intensity is larger ditch. The variation of sediment concentration and erosion rate has the same relationship with the formation of the falling ridge and the thin groove on the slope. The increase of rainfall intensity will not cause obvious increase of sediment concentration and erosion rate. However, The change of erosion rate has a great influence. Under heavy rain, the sediment concentration and erosion rate of loessial soil will increase rapidly and soon exceed the soil after the formation of slope rill. At the same time, the existence of thin furrow does not cause obvious change of sediment concentration and erosion rate, but the loessial soil is sensitive to the rill response on the slope, and the formation of the thin furrow will lead to the drastic increase of sediment concentration and erosion amount. The study provides theoretical guidance for the effective prevention and control of rill erosion in sloping fields.