Department of Watershed and Range Management, Faculty of Water and Soil, University of Zabol, Zabol, Iran.
Department of Watershed and Range Management, Faculty of Water and Soil, University of Zabol, Zabol, Iran.
Environ Res. 2023 Jan 1;216(Pt 3):114606. doi: 10.1016/j.envres.2022.114606. Epub 2022 Oct 26.
Dry playa surfaces can be extremely vulnerable to disturbance which breaks their surface crusts resulting in increased aeolian sand and dust emissions. Trampling by livestock and motor vehicles is an important source of this disturbance. The Hamoun Lakes in the Sistan region of Iran are a major source area of dust storms which are causing damage to infrastructure and communities. This study performed portable wind tunnel tests of controlled surface disturbance by animals (cow, sheep) and motor vehicles (automobile, motorcycle) on a silty playa surface of Hamoun Saberi lake. The aim of this study was to assess the effect of different levels of trampling and disturbed surfaces by both vehicles and livestock on dust emission at wind speeds of 6 and 12 m s. A significant increase of sediment emission was found with increased number of passes of vehicles and livestock and the degree of surface disturbance, more so at the high wind speed (12 m s). No significant differences were observed between a 10-20% disturbance level and an undisturbed surface, but statistically significant differences became apparent when disturbances reached 50-60% to 90-100% compared to undisturbed surfaces. Greater emission rates were reached by disturbances provided by automobile and cow compared to motorcycle and sheep, indicating greater trampling effects of automobile and cow likely related to greater weight and larger footprint. The automobile was the most surface-destructive of the four anthropogenic disturbances, providing emission in a lower number of passes compared to the motorcycle, cow and sheep. Better management of vehicle and livestock allocation on playas subject to disturbance, such as the Hamoun Lakes, will be a useful strategy to reduce disturbance and the frequency and intensity of dust storms.
干盐湖表面极其容易受到干扰而破裂，导致风沙和尘埃排放增加。牲畜和机动车的踩踏是这种干扰的重要来源。伊朗锡斯坦地区的哈姆恩湖是沙尘暴的主要源区，这些沙尘暴正在对基础设施和社区造成破坏。本研究在哈姆恩萨比尔湖的粉质干盐湖表面上，对动物（牛、羊）和机动车（汽车、摩托车）的受控表面干扰进行了便携式风洞测试。本研究的目的是评估不同程度的踩踏以及车辆和牲畜对表面的干扰对 6 和 12 m/s 风速下尘埃排放的影响。研究发现，随着车辆和牲畜通行次数的增加以及表面干扰程度的增加，沉积物排放显著增加，在高风速（12 m/s）下更为明显。在 10-20%的干扰水平和未受干扰的表面之间没有观察到显著差异，但当干扰达到 50-60%至 90-100%与未受干扰的表面相比时，统计上的显著差异变得明显。与摩托车和绵羊相比，汽车和牛提供的干扰达到了更高的排放率，这表明汽车和牛的踩踏效应更大，可能与更大的重量和更大的足迹有关。在四种人为干扰中，汽车是对表面最具破坏性的，与摩托车、牛和羊相比，汽车在较少的通行次数下就能提供排放。更好地管理干盐湖上的车辆和牲畜的分配，例如哈姆恩湖，将是减少干扰以及沙尘暴的频率和强度的有效策略。
