土壤初始含水量对黄土坡地水分运动与转化特征的影响

通过室内模拟降雨试验,研究了水蚀条件下初始含水量分别为1.3%、5.7%、9.7%、14.2%和18.9%时黄土坡地水分的迁移特征。结果表明随着土壤初始含水量的增加,坡面产流开始时间提前,坡地平均径流系数和径流量呈线性增加趋势;坡面径流含沙量与土壤初始含水量呈抛物线关系,在9.7%含水量左右存在最小值;土壤初始含水量越高,坡地累计入渗量越小,雨水转化为土壤水分的比率越小。在土壤初始含水量较高的雨季,建议采取保护性耕作措施,增加雨水入渗率,减少水土流失量。

Effect of Soil Antecedent Water Content on Soil Water Movement and Transport on Loess Slope Land

According to the results of simulation rainfall experiments,the transport traits of soil water on loess slope lands with different soil antecedent water content,1.3%,5.7%,9.7%,14.2% and 18.9%,respectively,are investigated.It shows that the initiation runoff time climbs with an increase in soil antecedent water content.The mean coefficient of surface runoff presents a linearity relation with soil antecedent water content,while the mean sediment content of surface runoff shows a parabola relation with it,with the lest amount of 9.7% land.The more the soil antecedent water content is,the more the accumulative infiltration amount,and the less percent of runoff translating into soil are.To promote the rare rainfall infiltration and lessen the water and soil loss,protective farming measures are suggested in rainy season.