【摘要】 根据黄土高原土壤入渗速率的明显地域差异,绘制了黄土高原土壤入渗速率分区图;文中对比了用双圈法测得的土壤稳定入渗速率与用水文资料推出的小流域土壤稳定入渗速率。更多还原

【Abstract】 The filtration rate of soils on Loess Plateau is different in various regions. In accordance with the steady infilatrition rate of the soils, Loess Plateau is divided into five regions of grade-Ⅰ and four regions of grade-Ⅱ. The regions of the highest filtration rate are located in Ziwuling, Liaoshan, Huanglongshan and the southern sector of Luliangshan Mt. on the central of the Plateau generally covered by secondary broadleaf forests of abores or brushes, the soil surface is commonly covered by a thick layer of litters; with good structure and greater porosity, the soils are the highest in filitritation rate. The regions of higher filtration rate include Hujialing, Dongzhiyuan of Gansu, Yijun, Zhouzhi, Meixian and Changan of Shaanxi, and Yicheng, Quwo of Shanxi.Results obtained showed that the relationship between the infiltration rate of soils and time can be described by the follow equation:f=f_c=（f₁-f_c）/（t^α）Where f is instantaneous infiltration rate （IR）, f_c the steady minimum IR. f₁ the initial maximum IR, α a constant, and t is time.It is found that the ratio for steady IR calculated from hydrological data to that obtained by two-circle mtthod is about 1.6—3.0.更多还原