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生产建设项目开发过程中形成的工程堆积体具有特殊的结构和复杂的物质组成,坡面侵蚀特征明显有别于一般农地.采用室内人工模拟降雨试验方法,研究降雨强度对红壤区不同砾石含量(0%、10%、20%、30%)工程堆积体产流产沙过程的影响.结果表明:坡面产流开始时间随降雨强度和砾石含量的增大而减小,减幅分别为48.5%~77.9%和4.2%~34.2%,且与降雨强度呈显著的幂函数关系.坡面径流流速和径流率均随产流历时呈先上升随后趋于稳定的变化趋势,降雨强度是其主要影响因素,砾石含量对其影响不显著.砾石对径流量的影响存在一个10%左右的阈值,1.0 mm·min-1雨强、10%砾石含量时坡面产流量最小;雨强>1.0mm·min-1时,10%砾石含量坡面产流量最大.随雨强增大径流量增加10%~60%.坡面含沙量在产流前6 min急剧下降后趋于稳定,随砾石含量增大,降雨强度对含沙量的影响减小.雨强>1.0 mm·min-1时,砾石具有显著的减沙效应,产沙量与降雨强度和砾石含量呈显著的线性函数关系.
The engineering deposit formed during the process of production and construction project has special structure and complicated material composition, and the erosion characteristics of slope are obviously different from those of general agricultural land.Using indoor artificial simulated rainfall test method, the effects of rainfall intensity on different gravel content (0%, 10%, 20%, 30%) on runoff and sediment production of the project. The results show that the start time of runoff decreases with the increase of rainfall intensity and gravel content, decreasing by 48.5 % To 77.9% and 4.2% to 34.2%, respectively, and showed a significant power function relationship with rainfall intensity.The slope runoff velocity and runoff rate both increased first and then tended to be stable along with the increase of rainfall duration, and rainfall intensity was the main factor The influencing factors and the gravel content have no significant effect on the runoff.The gravel has a threshold value of about 10%, the rainfall intensity is 1.0 mm · min-1, the minimum is the runoff when the content is 10% · Min-1, the flow rate of 10% gravel was the highest, and the runoff increased by 10% -60% with the increase of rainfall intensity.The sediment concentration on the slope stabilized sharply after 6 minutes before runoff, When the content is increased, the effect of rainfall intensity on sediment concentration is reduced, and the rainfall intensity is> 1.0 mm · min -1, gravel has a significant sediment reduction effect, sediment yield and rainfall intensity and gravel content showed a significant linear relationship.