宁南黄土丘陵区典型水保工程措施对土壤入渗性能的影响

Effects of Typical Soil and Water Conservation Project on Infiltration Capacity in Loess Hilly Regions of Southern Ningxia Hui Autonomous Region

土壤入渗性能是降水向土壤水转化的关键环节。利用双环法对宁南黄土丘陵区实施的88542水平沟整地、鱼鳞坑整地和机修水平梯田3种典型水土保持工程措施后土壤的入渗性能进行了试验研究。结果表明,实施水保工程措施后,土壤的入渗性能得到了明显改善,对土壤入渗性能改善程度表现为88542水平沟>鱼鳞坑>水平梯田,三者的入渗模型以Philip入渗公式精度最高,Horton入渗经验公式精度相对较低。土壤入渗性质的变化主要由于在实施不同水土保持措施后土壤容重和孔隙性发生了显著变化引起的。三种工程措施对土壤容重和孔隙度的改善程度和土壤入渗性能各项指标的变化高度一致。

Infiltration is a key step to transform rainfall into soil water. Infiltration capacity in three typical soil and water conservation projects （88542 level furrow site preparing, fish-scale pit site preparing, and level terrace） in the loess hilly regions of Southern Ningxia Hui Autonomous Region is studied By means of double ring method. Results showed that infiltration capacity was significantly improved after implementing the soil and water conservation projects. By the capacity, the order of the three engineering measures was 88542 level furrow 〉 fish-scale pit 〉 level terrace. The infiltration models for the engineering measures were all accord with power-exponent equation. The changes in soil bulk density and soil porosity was the main cause of the change in infiltration capacity. The improvement degree of soil bulk density and porosity by the three measures has a high concordance with the change of infiltration capacity.