Department of Watershed and Range Management, Faculty of Water and Soil, University of Zabol, Iran.
Department of Watershed and Range Management, Faculty of Water and Soil, University of Zabol, Iran.
J Environ Manage. 2020 Jul 1;265:110486. doi: 10.1016/j.jenvman.2020.110486. Epub 2020 Apr 9.
Windbreaks are barriers that are widely used to reduce wind speed and aeolian erosion. Most windbreak studies have been done in wind tunnels and generally used rigid objects rather than live plants and most of these studies report on the modification of the flow field and not on the effectiveness at reducing sediment transport. A series of experiments were conducted to monitor the effectiveness of a fourteen-rows Tamarix windbreak in the field and in particular to measure the reduction in sediment erosion and transport. Over the course of six dust storm events, with mean wind speed ranging from 9.4 to 18.2 ms, sediment flux and wind speed were measured at seven heights (z/h = 0.05, 0.1, 0.2, 0.4, 0.8, 1.4 and 1.8 where h is the mean height of the windbreak) at five locations upwind (x=-100 m), within (x = 100 and 256 m) and downwind (x = 448 and 560 m) of the windbreak. Largest reduction of sediment flux (a reduction of 50%) was observed at the end of the windbreak (x = 256 m). The decrease in silt and clay component is quite uniform but the relative concentration of sand (>100 μ) generally decreases within the windbreak and remained lower downwind of the windbreak compared to the upwind value in two of the three events for which sediment size data are available. The windbreak is effective in aeolian erosion control under a variety of dusty conditions and, in general, the potential of the windbreak is optimum due to its optimal porosity (39%) and structure (multiple-row design). Because Tamarix withstand harsh conditions, it is optimal to use it as a windbreak for wind and blown-sediment control in arid regions.
防风林是一种广泛用于降低风速和风沙侵蚀的障碍物。大多数防风林研究都是在风洞中进行的，通常使用刚性物体而不是活体植物，而且这些研究大多报告的是流场的变化，而不是减少输沙的效果。进行了一系列实验来监测十四行柽柳防风林在现场的效果，特别是测量减少风沙侵蚀和输移的效果。在六次沙尘暴事件中，平均风速范围为 9.4 至 18.2 米/秒，在防风林五个位置（上风侧 x=-100 米、场内 x=100 米和 256 米、下风侧 x=448 米和 560 米）的七个高度（z/h=0.05、0.1、0.2、0.4、0.8、1.4 和 1.8，其中 h 是防风林的平均高度）测量了泥沙通量和风速。在防风林的末端（x=256 米）观察到泥沙通量的最大减少（减少 50%）。粉砂和粘土成分的减少相当均匀，但在防风林内，沙粒（>100 μ）的相对浓度一般会降低，而且在三个有泥沙粒度数据的事件中，有两个事件的下风侧的浓度比上风侧的值要低。防风林在各种扬尘条件下对风沙侵蚀控制都很有效，而且，一般来说，由于其最优的孔隙率（39%）和结构（多行设计），防风林的潜力是最佳的。由于柽柳能耐受恶劣的条件，因此它是干旱地区防风固沙的最佳选择。
