低覆盖度沙蒿群丛的水平配置结构与防风固沙效果研究

 针对覆盖度小于28%的沙蒿群丛，通过野外测试和风洞模拟实验，研究了行带式、等株行距和随机不均匀等3种水平配置格局的防风固沙效果及其流场特征。结果表明：①行带式配置格局具有非常显著的阻碍和降低风速的作用，流场结构稳定规则；等株行距次之；随机不均匀配置格局内局部有风速抬升现象流场结构复杂多变。②行带式配置格局带间形成“凹月”形稳定沙面并能出现结皮，流沙被完全固定，而随机不均匀分布的沙蒿群丛内有明显的风蚀现象。③行带式配置格局在带的背风侧和迎风侧分别形成4.0 m和0.5 m的一个风速显著降低区，成为提高防风固沙效果的核心。

Allocation of Artemisia halodendron Association with Low Coverage and Their Sand-fixing and Wind-preventing Effects

The study object of this thesis is Artemisia halodendron shrub association with coverage less than 28%.By field observation and simulation experiment in wind tunnel,we studied their wind-preventing and sand-fixing effects as well as the flow-field features when in belt,equal distance(plant-to-plant and row-to-row),and random distribution.(1) Belt Artemisia halodendron pattern can remarkably reduce wind speed and its flow field is steady and regular,which followed by the equal distance pattern;Random distributed pattern appeared phenomenon of increasing wind speed in part area and its flow fields is complex.(2) Belt pattern resulted in \!concave moon\" sand surface and inhabited soil crust,therefore,shifting sands have been fixed;Random pattern existed remarkable wind erosion.(3) There are two remarkable wind-reducing regions with 4.0 m in leeward and 0.5 m in windward of belt pattern.They become the core of improving wind-preventing and sand-fixing effects.