选取陇东黄土包气带为研究对象,综合运用数理统计与对比分析相结合的方法,研究黄土地区包气带土壤水分、水势变化特征和土水势构成结构,结果发现,在陇东黄土塬区,坡头荒地等较干旱、沙质土壤中,包气带水分变化呈对数分布特征,而耕作土壤其水分含量特征则不满足这种类型.在土水势构成方面,溶质势所占比例平均约为20%,其中坡头荒地约占15%,耕地中约占25%;基质势所占比例最大,在坡头荒地占近80%,耕地样本的平均比例超过60%.溶质势各分势构成方面,起主导作用的阴离子为HCO,起主导作用的阳离子为Ca.黄土塬区HCO和Ca所占溶质势的比重分别约为50%和25%;Na和Cl各约占10%.%This paper studys soil moisture distribution and composition of soil water energy at unsaturated zone in East Gansu. The results are as follows: Soil water mass content characteristics are logarithmic in the more arid Potou wasteland,sand and non-cultivated soil in the Loess Plateau of East Gansu, while moisture content of the arable soil is affected by its soil texture, displaying quite difference. In the unsaturated zone of the Loess Plateau, the proportion of solute potential is about 15％ at Potou wasteland, while it can be up to about 25％ in the farmland. Matric potential accounts for nearly 80％ in Potou of the arable and is 60％ in average content in farmland, which is of the largest proportion of the soil water pertential. HCO3- plays a leading role of anios in the solute potential of the unsaturated zone, and leading cation is Ca2 + in the loess area. Soil solute potential in the weight of the plasma ions is the largest HCO3- and Ca2+ , which is about 50％ and 25％ respectively of the solute potential in the Loess Plateau, Na+ and Cl- are about 10％.
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