【摘要】 在西北地区黑河流域下游的额济纳绿洲选择 3个土壤剖面采集不同深度土壤样品和潜水样品进行测试 ,并在野外观测非饱和带不同深度的水土势变化。结果表明 ,SO2 -4是非饱和带土壤和地下水中的主要离子成分 ,土壤和地下水呈偏碱性。土壤易溶离子含量随深度大体上呈减少趋势。绿洲非饱和带发育有收敛型和发散型零通量面 ,自夏季至冬季 ,零通量面变得不清晰直至消失。在非饱和带中 ,土壤易溶盐含量、含水量和总水土势随深度的变化趋势基本相同 ,植物根系的吸收对水分和盐分的垂直分布有着重要的影响更多还原

【Abstract】 Three soil profiles were selected from the Ejin Oasis in the lower reaches of the Heihe River in northwest China to collect soil samples at different depths and groundwater samples for determination of chemical compositions of the samples, and to measure the changes in soil moisture potentials at different depths of the profiles. The results show that SO 2- 4 is the major anion in both the soluble ions of the soil in the unsaturated zone and the ions in groundwater in the saturated zone. Both the soil and the groundwater are in a weakly acidic environment. The concentrations of soluble ions of the soil tend to decrease with depth. Both convergent and divergent zero flux planes were observed in the unsaturated zone in the oasis. From summer to winter the zero flux planes became indistinct and even vanished. The concentrations of soluble salts, water contents and total soil moisture potentials are found to have a similar tendency to change with depth. Water extraction by root systems is believed to have an important bearing on the vertical occurrence of the water and salts in the unsaturated zone in the oasis.更多还原