几种土壤的细沟侵蚀过程及其影响因素

Research on processes and factors of rill erosion

  • 摘要: 通过间隔为11h的二次人工模拟降雨和冲蚀槽试验研究了10种土壤的侵蚀过程,发现在第2次降雨中大多数土壤出现了细沟侵蚀形式。采样微形态观察发现,在第1次降雨中形成结皮的土壤在第2次降雨中出现了细沟侵蚀;产流产沙观测发现所有出现细沟侵蚀的土壤在第1次降雨中径流含沙量逐渐减少,而第2次降雨中有一个先剧增后减少的过程。土壤理化分析及多元逐步回归分析结果表明,土壤颗粒组成、有机质含量、铁铝含量等因素对细沟侵蚀的影响表现不明显,而与土壤团聚体有关结构指标、细沟侵蚀、产流产沙速率及总量呈显著相关关系。分析表明,团聚体分散度、崩解速率与渗透系数之比两个指标能较好地预测细沟侵蚀发生的可能性,同时也能很好地预测侵蚀产沙量。

     

    Abstract: The erosion processes of 10 kinds of soil were studied with the experimental erosion slots and 2 artificial rainfalls with an interval of 11 hours.As a result,rill erosion has been observed in most soils during the second event of rainfall.The observations about runoff and sediment suggest that sediment concentration and runoff rate of all the soils with rill erosion decrease in the first rainfall,and increase then decrease in the second rainfall.The results of physical and chemical analysis and the multi-factor regression show that soil texture,content of soil organic matter,ferrous and aluminous compounds have an unnoticeable effect on rill erosion,while indexes of soil structure concerning soil aggregates have a close correlation with the rill erosion,the velocity and grosses of runoff and sediment.The degree of aggregate despersibility and the ratio of collapsing rate to infiltration rate work well in predicting possibility of rill erosion and the sediment discharge as well.

     

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