黄土丘陵区小流域横断面土壤水分的空间分布特征

Soil Water Diversification Character in a Cross Section of Small Watershed in Loess Hilly Area

以黄土丘陵区的纸坊沟小流域为研究对象,研究了横断面上土壤水分空间变化特征,得出如下规律:①从总体来看,土壤水分含量大致是阴坡高于阳坡,坡下高于坡上,地形起着决定性作用,但植被的影响也非常重要。②在小流域断面水分分布中,乔木林地的平均含水量最低,灌木林次之,草本植被最高。表明丘陵区最适宜的植被应是草本植被和灌木群落。③植被的生长弱化了断面地形变化的影响,刺槐的阴阳坡、上下坡的土壤水分含量趋于接近,柠条的生长良好时的大耗水量也使阴坡和坡下的水分优势减弱,长势良好的草本群落使梁峁坡上的土壤水分状况优于其他坡位。④纸坊沟小流域除阴坡草本植被外,全部有土壤干层的存在,但并不影响植被的正常生长,因此,在植被恢复良好的地区,干层的产生是正常的。

According to the study on the Soil water diversification character in a cross section in Zhifang small watershed in loess hilly area, the following conclusions was drawn： ①As a population, the content of water in shady slope is higher than in sunny slope and in the lower slope is higher than in the up slope, so the landform is the deciding factor, while the vegetation is also important. ②The content of water in arboreal grounds is the lowest, the shrub ground＇s is better and the grass ground＇s is best. So the feasible vegetations are grass ground and shrub ground in loess hilly area.③The growing of vegetations weaken the effect of slope＇s change. The contents of robinia pseudoaccia are similar in shady slope and sunny slope, lower slope and up slope. The great water consumption of well grown caragana korshinskii make the content of water in shady slope and lower slope lower, and the grass community in sloping land have a higher water content.④There are dried soil layer in Zhifang small watershed except the grass vegetation in shady slope, but the vegetation can grow well, so the dried soil layer is very normal in well vegetation recovery area.