西北地区黄土层中的脉管水规模较小，定位困难。

The vascular water in loess is difficultly located for small scale in northwest China.

集中的灌溉补给，在黄土层中形成二元非饱和渗流。

The unsaturated irrigation supply has duality in yellow soil.

岩性底层是由砾石，沙质土，粘土与黄土层组成。

The lithologic substratum is made of gravel, sand and clay with a layer of loess.

主要内容包括采用分级堆填过程模拟风积黄土层的初始应力场；

The initial geological stress of loess was simulated by grading fill;