挡风墙设计及其在呼伦贝尔沙地治理中的应用

为探索呼伦湖流域沙化严重的斑块状区域生态修复的治理模式,研发设计条形孔2.0 m高度(Ⅰ)、条形孔1.5 m高度(Ⅱ)、条形孔1.0 m高度(Ⅲ)、方形孔1.0 m高度(Ⅳ)和圆形孔1.0 m高度(Ⅴ)5种类型的可移动挡风墙作为沙障,并对其防风效能进行对比研究,明确挡风墙背风侧不同距离、距地表不同高度的风速及表层土壤含水量特征,为大风频发地区的挡风墙设置提供参考依据。结果表明:5种挡风墙均可在有限距离内降低风速,且距地表0.5 m高度处的防风效能均优于1.0 m高度处;其中在挡风墙背风侧1 m、距地表0.5 m高度处,防风效能为挡风墙Ⅴ(87.30%)>Ⅰ(83.91%)>Ⅱ(83.29%)>Ⅳ(80.20%)>Ⅲ(74.66%),表层土壤保水能力为挡风墙Ⅴ>Ⅰ>Ⅱ>Ⅳ>Ⅲ,制作成本为挡风墙Ⅰ>Ⅱ>Ⅴ>Ⅳ>Ⅲ。较适宜呼伦湖流域环境的挡风墙结构参数:1.5 m高,条形孔;1.0 m高,圆形孔。

Design of wind-break walls and their application in Hulunbeier sandy land control

The grassland desertification is serious in Hulun Lake Basin. 5 different heights and hole types of movable wind-break walls (Ⅰ:2.0 m high, stripe-shaped holes, Ⅱ:1.5 m high, stripe-shaped holes, Ⅲ:1.0 m high, stripe-shaped holes, Ⅳ:1.0 m high, square holes, Ⅴ:1.0 m high, circular holes) were developed and designed as sand barriers in order to explore the ecological restoration modes in serious desertification patches. The windbreak effects of wind-break walls were compared and the characteristics of wind speed at different distances and heights from the surface and surface soil moisture content behind them were determined, which could provide references for the installation of wind-break walls in areas with frequent winds. The results showed that, all wind-break walls could reduce the wind speed within limit distance and the windbreak effect at 0.5 m from the surface were higher than that at 1.0 m. At the distance of 1 m behind the wind-break walls and the height of 0.5 m from the surface, the windbreak effects were Ⅴ(87.30%)>Ⅰ(83.91%)>Ⅱ(83.29%)>Ⅳ(80.20%)>Ⅲ(74.66%). The order of water holding capacity of surface soil was Ⅴ>Ⅰ>Ⅱ>Ⅳ>Ⅲ and the cost of them was Ⅰ>Ⅱ>Ⅴ>Ⅳ>Ⅲ. Therefore, the structural parameters of the wind-break walls that were more suitable for Hulun Lake Basin were as follows: 1.5 m high, stripe-shaped holes; 1.0 m high, circular holes.