黄土丘陵区人工油松林地土壤入渗特征的研究

油松 (Pinustabulaeformis)人工林是黄土丘陵区半湿润地区的主要人工林类型 ,具有良好的水土保持和水源涵养功能。通过对人工油松林地和荒坡地土壤入渗特征的研究 ,发现 :人工油松林地的入渗速率显著高于荒坡地 ,其阴坡和阳坡土壤的入渗速率仅在坡顶部有一定的差异 ,而在坡的中下部并不明显 ;而荒坡地的初始入渗速率和最终入渗速率均是阴坡高于阳坡。由于来源坡上部的泥沙在下部沉积 ,致使坡下部形成一个入渗能力较低的致密层 ,降低了坡下部的入渗速率 ,使入渗速率在坡位上的空间变化表现为坡上部 >坡中部 >坡下部。对于黄土丘陵地区而言 ,水分入渗过程采用方正三方程和Kostiakov方程拟和较好 ,两个方程结合使用可更好地说明土壤的初始入渗速率和最终入渗速率

STUDY ON THE CHARACTERISTICS OF SOIL INFILTRATION OF PINUS TABULAEFORMIS STAND IN THE LOESS HILLY AREAS

Pinus tabulaeformis stand is the major artificial forestry in the semi-humid Loess hilly areas, and has the function of soil and water conservation.Through the study on soil infiltration characteristics of Pinus tabulaeformis stand and bare-slope, we found that infiltration rate of Pinus tabulaeformis stand was higher than that of bare-slope. For infiltration rate, there existed great difference on the upslope of the south and north slopes but no difference on the middle slope and down slope. Both initial infiltration rate and final infiltration rate of south slope were higher than those of north slope on bare-slope. The spatial changes of infiltration rate along slope was upslope>middle slope>down slope. The reason may be related with that sediment from the upslope deposited on the down-slope so that a layer with low infiltration rate was formed on the down-slope. For the Loess hilly areas, the process of infiltration could be well described by Fang Zhengsan equation and Kostiakov equation, mixed use of the two equations can fully describe the initial infiltration rate and final infiltration rate.