摘要
为了对太行山区草被类型的水土保持功能有个具体估价,通过人工降雨测定截留量,观察草被对降雨的截持和传导过程,调查枯落物量、土壤、根系等方法,对降雨从落到草丛至渗入土壤中的各个环节,分别进行了研究。结果表明,盖度70%以上,以黄背草、白羊草为主的草被类型,当降雨达20mm时,截留量已达饱和状态,总截留量为4.56mm;雨滴经层层草叶的传导,到达地面时的动能近于0;枯落物量平均4.45t/hm^(2),可吸收降水0.827mm;0~5cm、5~10cm、10~15cm土壤层的根系密度分别为31、33、28条/100cm^(2);非毛管孔隙度为3.22%,渗透速度为4.07mm/min。草被的水保功能主要在于能消减雨滴动能,增加地面枯落物量,增强土壤的渗透力和抗蚀力。
The detailed processes of rainfall from reaching grass layer to penetrating into soil were studied by measuring its interception,observing the holding and conduction in grass cover,and surveying litter amount,soil and root system etc.The results showed that,with the coverage of 70%,the interception of the grass cover type dominated by Themeda triandra var.juponica and Bothriochloa ischaemum was found saturated when the precipitation was 20mm.Its total interception was 4.56mm.The kinetic energy of rain drops when they reached ground was about zero after going through the grass leaves.It could obsorb 0.827mm of rainfall.The root densities of the various soil layers of 0~5cm,5~10cm and 10~15cm were measured as 31,33 and 28 roots per 100cm2.The non-capillary porosity was 3.22%.The penetrating speed was 4.07 mm/min.The functions of grass cover on soil and water conservation rely mainly on diminishing kinetic energy of rain drops,increasing litter amount upon the soil surface,enhancing the penetrability and erosion-resistance of soil.
作者
张金香
钱金娥
Zhang Jinxiang;Qian Jine(Forestry Research Institute of Hebei,Shijiazhuang O50061)
关键词
草被类型
水保功能
截留降雨
水土保持
type of grass cover
function of soil and water conservation
rainfall interception
kinetic energy of rain drops
Taihang Mountain
