stratification
[英][ˌstrætɪfɪˈkeɪʃn][美][ˌstræt来自əfɪˈkeʃən]
n.层理; 成层; 层化; 尼均丝素照切息宜水田视分层;

例句:

1.
Stratification threatens this recycling system by suppressing the vertical增果散劳依语求住岩完movement of water.
而海水分层会抵制水的垂直流动，从而威胁着这种再循环系统。

2.
And global warming encourages stratification because it turns the ice into alayer of fresh wate英r that sits on the surf360问答ace.
而全球变暖却推动了海水分层，因为变暖会让冰融化成为覆盖着海面的新鲜水层。