黄土高原生物利用型土壤干层的水文生态效应研究

Hydro-ecological effect of the soil dry layer as affected by biota use in the Loess Plateau.

对黄土高原高产农、林、草、灌、果5种植被1000cm土层土壤剖面含水量多点测定结果表明,各植被类型均存在不同程度的生物利用型土壤干层,该土壤干层的水文作用表现为增强土壤-植被-大气间垂直水分交换,阻碍入渗降雨转化为地下径流,削弱植被对枯水季节低径流量的补偿能力,其生态效应是恶化植物生长的土壤水分环境,削弱土壤水库对年际干旱的调节能力。

According to measured data from ten meters below surface in the fields of crop land, woodland, grassland, shrub land and orchard with high production, the used soil dry layer with different degrees was found. The hydrological effect of dry layer shows that the model of water cycle has been strengthened in the pathway of soil, vegetation and atmosphere . The transformation from surface runoff to ground runoff may be prevented in vegetation land with high production and outflow in quantity from these lands may also be decreased owing to the great amount of water deficit in soils. It is also pointed out that the ecological effect of dry layer is to weaken the soil water environment of vegetation growth and decrease the regulation of soil water to plant in semiarid area of the loess region.