含砾石土壤坡面流速及产流产沙过程研究

Flow velocity and processes of runoff and sediment generation on soils containing gravels

在模拟降雨条件下对5种土壤(砾石质量分数分别为0、10%、20%、30%、40%)的坡面流速及产流产沙过程进行研究,以期深入了解含砾石土壤的水土流失过程。结果表明:含砾石土壤的坡面流速和径流量大于不含砾石的土壤;在降雨初期0～10 min内,含砾石土壤的产沙量随时间呈显著增加趋势,峰值出现在10 min左右,随后产沙量逐渐降低;降雨后期30～60 min内,含砾石土壤的产沙量又呈增加趋势,尤其是砾石含量为30%和40%的土壤产沙量显著增加,且随时间有一定波动。试验中,5种土壤的总产沙量与砾石含量正相关,径流含沙率与产沙量则呈显著线性正相关。

In this study,the flow velocity and the processes of runoff and sediment generations along the slopes for five soils（gravel mass contents were 0,10%,20%,30%,and 40% respectively） were investigated under rainfall simulation experiments in order to understand the soil and water loss process on the soil containing gravels.The results indicated that the flow velocity for soil containing gravels was larger than the soil without gravels.During the initial 0-10 min of the rainfall,sediment yields on the soils with gravels increased sharply with time and the peak period of sediment generations appeared around 10 min.Then,sediment yields decreased gradually.At the later stage of the rainfall（30-60 min）,the sediment yields for the soils with gravels increased again especially for the soils with 30% and 40% gravel contents their sediment yields enhanced significantly and fluctuated with time.In the experiments,the total sediments yield was positively linked to the gravel content in the soil and the sediment concentration was positively linearly related to the sediment yield.