图3. 裸露沙丘和植被覆盖沙丘的移动速度和方向A:裸露沙丘(39°09′21″N、108°32′06″E); B:植被覆盖沙丘(39°09′39″N、108°31′37″E)
Fig.3. The migration rate and direction of bare dune and dune with vegetation