Abstract:

This study evaluates the sand fixation efficiency of clustered and horizontally laid sand barriers made from Salix psammophila branches through wind tunnel simulations. The results show that：（1） A distinct deceleration zone formed behind each sand barrier， while a pronounced jet flow region developed above the first barrier. The 1 m×1 m and 1 m×1.5 m barrier configurations demonstrated superior windbreak effectiveness.（2） Under varying wind velocities， the sand surface protected by S. psammophila sand barriers generally exhibits an erosional state. The degree of sand surface erosion beneath these barriers increases significantly with higher wind speeds. Within the grid system formed by S. psammophila sand barriers， the foremost section experiences the most severe erosion， with the intensity gradually diminishing in subsequent sections.（3） The wind-sand flow structure in a wind tunnel without sand barriers exhibits an exponential decay curve. In contrast， the wind-sand flow structure in the presence of sand barriers demonstrates a dynamic distribution， primarily due to the obstruction formed by the barriers， which alters its characteristics compared to the barrier-free scenario.（4） The 1m×1m， 1 m×1.5 m， and 1 m×2 m sand barriers showed sediment accumulation reductions of 100%，79%， 72%， and 51%； 100%， 94%， 89%， and 74%； and 100%， 78%， 76%， and 78% at wind speeds of 8 m·s^-1， 12 m·s^-1， 16 m/s， and 20 m/s， respectively， This suggests that S. psammophila sand barriers exhibit significant sand-fixing potential， with the 1 m×1.5 m configuration showing optimal performance.

Key words: Salix psammophila, clustered and horizontally laid sand barriers, wind tunnel simulation, sand fixation efficiency