汇流强度、坡度及侵蚀泥沙颗粒分形对工程堆积体坡面侵蚀的影响

Influence of Flow Intensity,Slope and Soil Particle Fractal Dimension on Slope Erosion of Engineering Accumulation Body

为了探讨汇流强度、坡度和侵蚀泥沙颗粒分形对堆积体坡面土壤侵蚀的影响,选用3种土壤(风沙土、红土、塿土),4个汇流强度(8,12,16,20 L/min),在3个坡度(28°,32°,36°)堆积体坡面上进行野外径流冲刷模拟试验。结果表明:(1)汇流强度和坡度的交互作用对坡面平均流速的影响最大。3种土壤坡面流流速均随汇流强度的增加递增1.00~1.49倍,均随坡度增加递增0.99~1.29倍。(2)汇流强度、坡度、土壤颗粒分形维数三者之间的交互作用对坡面平均产流率影响最大,而汇流强度对径流量影响最大。3种土壤下垫面坡面产流率、径流量均随汇流强度的增加而增加,分别递增1.09~6.10,1.05~5.74倍,均随坡度增加而增加,分别递增0.80~2.59,0.82~2.59倍。(3)汇流强度和坡度的交互作用对产沙率和产沙量影响最大。3种土壤坡面产沙率、产沙量均随汇流强度的增加而增加,分别递增1.17~5.67,1.17~5.20倍,均随坡度增加而增加,分别递增0.96~3.32,0.94~7.54倍。研究结果可为不同土质的工程堆积体坡面土壤侵蚀预测及流失防控提供理论参考。

In order to investigate the effects of flow intensities,slope gradient and fractal dimension of erosion sediment particles on soil erosion on slope surface of accumulation body,three soils(aeolian sandy soil,red soil and Lou soil)and four flow intensities(8,12,16 and 20 L/min)were selected.Field runoff scouring simulation experiments were carried out on three slopes(28°,32°and 36°).The results showed that:(1)The interaction of flow intensity and slope had the greatest influence on the average velocity of slope.The velocity of slope flow of the three soils increased by 1.00~1.49 times with the increase of flow intensities and 0.99~1.29 times with the increase of slope.(2)The interaction among flow intensities,slope and fractal dimension of soil particles had the greatest influence on the average runoff yield on slope,while flow intensity had the greatest influence on runoff.The runoff rate and runoff yield of the three soils increased with the increase of flow intensities by 1.09~6.10 and 1.05~5.74 times respectively,and increased with the increase of slope by 0.80~2.59 and 0.82~2.59 times respectively.(3)The interaction between the intensities of flow and slope had the greatest influence on the sediment yield and sediment yield.The sediment rate and sediment yield of three soils increased with the increase of flow intensities,increased by 1.17~5.67 and 1.17~5.20 times respectively,and increased by 0.96~3.32 and 0.94~7.54 times respectively with the increase of slope gradients.These research results could provide a theoretical reference for soil erosion prediction and loss control of engineering accumulation slope with different soil properties.