浅层滑坡影响下草被沟坡有机碳流失试验研究

Experimental study of organic carbon loss on grass slope under the influence of shallow landslide

以裸地小区为对照条件,通过在草被小区进行原型模拟降雨试验,研究浅层滑坡影响下草被沟坡的有机碳流失特征。研究结果表明,浅层滑坡发生后,泥沙有机碳含量下降42.3%,有机碳流失速率增大64.9~113.0倍,泥沙有机碳富集比由1.16~1.24下降至0.43~0.87,泥沙有机碳在总有机碳中的占比达到92.9%~96.6%。浅层滑坡发生前,有机碳流失速率与径流率、产沙率均极显著正相关;浅层滑坡后,有机碳流失速率仅与产沙率极显著正相关。

Taking the bare plots as a control,the simulated rainfall experiments were carried out in grass plots to study the characteristics of organic carbon loss on grass slope under the influence of shallow landslides.The results showed that after the occurrence of the shallow landslide,the organic carbon content of sediment decreased by 42.3%,the organic carbon loss rate increased by 64.9~113.0 times,the enrichment ratio of sediment organic carbon decreased from 1.16~1.24 to 0.43~0.87,and the proportion of sediment organic carbon in total organic carbon increased to 92.9%~96.6%.Before the shallow landslide,the organic carbon loss rate was significantly correlated with the runoff rate and sediment yield rate(P<0.01).After the shallow landslide,the organic carbon loss rate was only significantly correlated with the sediment yield rate(P<0.01).