黄土地表生物结皮对土壤贮水性能及水分入渗特征的影响

采用双环法对山西省偏关县3种结皮覆盖下(苔藓藻结皮、藻结皮和薄层藻结皮)土壤的贮水性能和渗透特征进行了对比研究.结果表明:不同结皮覆盖下土壤的贮水能力受结皮厚度和孔隙度状况的影响较大,0～10 cm土层饱和贮水量为502.69～525.80 t/hm2 ,滞留贮水量为169.71～198.29 t/hm2;初渗速率的变化范围为5. 19～11.10 mm/min,无结皮最高,苔藓藻结皮最低;稳渗速率变化范围为1.6 7～2.67 mm/min.采用的3种入渗模型(Kostiakov模型、Horton模型和Ph ilip模型)中Horton模型的拟合值更接近于实测值, 决定系数R2在0.98～0.99,更适用于描述本研究区具有生物结皮土壤的入渗特征.

Effects of biological soil crusts on soil water storage capability and permeability in loess area

Method of double-rings was employed to study the characteristics of soil water storage capacity and permeability of three types of biological soil crust (moss -algal crust, algal crust and thin-layer algal crust) on the loess area of Pia nguan, Shanxi Province. The results showed that water storage capacity of differ ent crust types is influenced by the thickness of biological soil crust and soil porosity, the water storage capacity was from 502.69～525.80 t/hm2 and the no n-capillary water capacity was from 169.71～198.29 t/hm2 with in 10mm soil de pth of the three crust types. The soil initial permeability was from 5.19～11.10 mm/min, the no crust soil had the highest velocity and the moss-algal crust so il had the lowest velocity. The solid permeability rate was from 1.67～2.67 mm/m in. By using the Horton seepage model, the fitted value was close to measured va lue and the range of determination coefficient was 0.98～0.99. Therefore, the Ho rton seepage model was applied to describe the soil infiltration characters whic h covered with biological soil crust in experimental region.