碎石含量影响下紫色土坡面径流流速变化过程及土壤侵蚀的阶段性

在室内人工模拟降雨条件下,对6种不同碎石含量(0,5%,10%,20%,30%,40%)的土壤侵蚀产流产沙的过程进行模拟研究。结果表明:碎石含量对径流流速的影响不显著,随着碎石含量的增加,平均径流流速呈减小的趋势。碎石含量对坡面侵蚀径流含沙率影响显著(F=30.076,P0.05),随着碎石含量的增加,径流含沙率呈降低的趋势。累积产沙量与降雨历时具有对数相关关系,碎石含量为5%时相关性最大,碎石含量越大累积产沙量递增速率越小。土壤中碎石混合通过改变土壤的物质组成和结构,增强土壤的抗蚀性和抗冲性,随着碎石含量的增加,土壤流失量逐渐减少,土壤侵蚀速率显著降低。

Processes of runoff velocity and stages of soil erosion under the effect of rock fragment content

Experiments were conducted to evaluate the effect of six different rock fragment contents (0,5%,10%,20%,30%,40%) on runoff and sediment yield with simulated rainfall equipment on the purple soil hillslope.The results showed that:content of rock fragment has no significant effect on the runoff rate.The increase of rock fragment will promote the wetting front downward migration;The sediment yield rate of the slope erosion was significantly effected by rock fragment content(F=30.076,P<0.05).With the increasement of rock fragment content,the rate of sediment yield decreased significantly.There was a linear correlation between cumulative erosion sediment yield and rainfall duration,which was maximum when rock fragment content is 5%.The more of rock fragment content,the lower of the sediment yield increasing rate.By changing the composition and structure of soil,soil mixed with rock fragments improved soil anti-erodibility and anti-scouribility.With the increasement of rock fragment content,the soil loss amount decreased gradually and the rate of soil erosion decreased significantly.