新疆地区干旱，各工程筑坝土料基本都是由风化层经水流搬运至洼地及风化沉积土料，经蒸发形成受高钠影响具有一定分散性。土料的分散性是决定土料能否用于工程的重要因素，也是土坝稳定性评价的一项重要指标。对新疆某工程土料采用蒸馏水和河水2种方案进行分散性试验，认为河水中钙离子含量较高，进入土体后能抑制土样的分散性，河水对黏土分散性具有明显的影响。

Because to Xinjiang belongs to the arid areas, the materials of the hydraulic engineering basically are weathered soil. After evaporation the soil is dispersed due to sodium. Soil’s　dispersibility is the important element to determine whether it is suitable for the engineering and to evaluate an index of dam’s stability. By means of the experiment using the distilled water and river water, the test indicates the calcium content of the river water is higher and it can restrain the soil’s dispersion. So the water of the river has the evident affect on the clay’s dispersion.