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本研究采用体积置换法获得的细沟水流含沙量随沟长变化的过程数据,估算得到不同水力条件下的最大含沙量,进而计算水流的输沙能力.实验采用不同坡度(5°,10°,15°,20°,25°)、流量(2,4,8min/L),测量紫色土细沟侵蚀输沙数据,分别采用细沟侵蚀含沙量随沟长变化的输沙过程的实测和拟合最大含沙量、细沟侵蚀剥蚀率为0时的含沙量3种方法确定紫色土细沟水流的输沙能力.结果显示,输沙能力随流量呈线性增加,随坡度呈对数增大,流量较坡度对输沙能力的影响更大.同一坡度下,流量越大,输沙量趋于输沙能力所需的沟长越短;同一流量下,坡度5°~15°时,坡度越大,输沙量趋于输沙能力所需沟长越短,坡度15°~25°时,输沙量趋于输沙能力所需沟长随坡度增加变化不大.相关性分析可知,3种方法计算得到的输沙能力基本一致.
In this study, the maximum sediment concentration under different hydraulic conditions was estimated and the sediment transport capacity of water flow was calculated by using the process data of sediment concentration change with groove length obtained by volumetric displacement method. The data of sediment transport in purple soil were measured by using the data of sediment concentration (10 °, 15 °, 20 °, 25 °) and flow rate (2,4,8min / L) The maximum sediment concentration and the sediment concentration when the erosion rate of rill erosion is 0. The results show that the sediment transport capacity increases linearly with the flow rate and decreases with the slope The logarithm increased, and the flow rate had a greater influence on the sediment transport capacity than the slope.The greater the flow rate, the shorter the channel length required for sediment transport to reduce the sediment transport capacity at the same slope; the slope 5 ° ~ At 15 °, the greater the slope, the shorter the channel length required for sediment transport to reduce sediment transport capacity. When the slope is between 15 ° and 25 °, the groove length required for sediment transport tends to be less than that for slope with little increase in slope capacity. Correlation analysis shows that the sediment transport capacity calculated by the three methods is basically the same.