降雨强度对黄土区不同土地利用类型入渗影响的试验研究

降水入渗规律的研究可为流域水文过程的预测和评价提供重要的科学依据。通过野外人工模拟降雨的试验方法,研究了短历时暴雨条件下,不同降雨强度对林灌地、封禁草灌地以及裸露农地3种不同土地利用类型下土壤入渗的影响。试验结果表明:不同土地利用类型之间,林灌地和封禁草灌地的土壤入渗速率差异不明显,而与裸露农地之间的差异显著,且前者具有较大的入渗速率,后者入渗速率较小;在不同降雨强度下,林灌地和封禁草灌地的土壤水分入渗速率有随雨强增大而增大的趋势,对于坡耕裸地,随着雨强的增大,土壤水分入渗速率有降低的趋势;通过对试验数据的回归分析,建立了林灌地和封禁草灌地在短历时暴雨条件下的土壤水分入渗经验模型。

Effects of Different Types of Land-uses and Rainfall Intensities on Soil Infiltration in Loess Plateau of China

Study of water through soil infiltration may offer a scientific support for prediction and evaluation of watershed hydrological processes.Effects of three types of land-uses such as forest-shrub land,grass-shrub land and bare farmland,and different rainfall intensities on water through soil infiltration were studied by field artificial simulation rainfall.Under short-time storm,the differences in infiltration rate were obvious between the bare farmland and other two types of land-uses,but it was inconspicuous between forest-shrub land and grass-shrub land.The infiltration rate of both forest-shrub land and grass-shrub land was higher than that of bare farmland.Under different rainfall intensities,infiltration rate of forest-shrub land and grass-shrub land showed the tendency that infiltration rate was more and more higher with the increase of rainfall intensity.Infiltration rate of bare farmland,however,showed an opposite tendency.By the regression analysis of date observed from this experiment,a model of infiltration for forest-shrub land and grass-shrub land was constructed.