Correct

固沙

/ gù shā / 
Strokes

Definition

sand fixation

Example

As a Verb

stabilize sand dunes

1
Zhíshù
植树
kěyǐ
可以
gùshā
固沙
  
。

Trees help to fix sand.

2
Huàxué
化学
gùshā
固沙

chemical sand-fixation

3
Gùshā
固沙
zàolín
造林

dune-fixing afforestation