关键词: 灌木群丛, 低覆盖度, 风洞实验, 风流结构, 防风效果

Abstract: Low-overed shrub is a kind of vegetation that widely distributes and has important significance in arid and semi-rid areas, and is also the reference vegetation that should be obeyed in restoring. The paper simulated the wind flow structure and windbreak effect of different arranged shrub at about 20% coverage in wind tunnel. Results have been obtained as follows: ①The windbreak effect of the three patterns is the best within the belt pattern, reducing wind speed at 36%~43%; second within the equal-istance pattern, reducing wind speed at 7%~28%; the worst within the random-istributing pattern, and even wind speed increased in some places. ②The flow field structure of belt pattern is regular, that of random pattern is complicated, and that of equal-istance pattern lies between the above two. ③As for belt pattern, the windbreak effect is better when inter\|belt distance is 56 cm or 64 cm than is 32 cm or 40 cm, showing that the windbreak effect didn’t weaken when the vegetation coverage decreased to 11%~13%. ④The windbreak effect of “two-row in one-belt pattern” is better than that of single-low pattern, and even more effective when wind speed increased to some extent.

Key words: shrub, low coverage, wind tunnel experiment, wind flow field, windbreak effect