The size of sand particles also affects the distance of dust flight. For example, the components of Horqin sandy land are mainly medium and fine sand and silty sand. Ordos and other places contain 80% fine sand and silt. The loose sedimentary environment and suitable circulation conditions make these areas the high incidence area and source area of sandstorm. It is also one of the causes of the formation of the vast and flat landform in the dust producing area.
荒漠化扩大了沙尘源,增加了沙尘暴天气的发生,近年来气候干暖化和人为活动强度加大,造成荒漠化速度加快。荒漠化与经济活动强度及人口数量增加成正相关。人口的增加加大了对土地资源和水资源的压力,低素质的人群中便出现乱砍滥伐、过牧和水资源利用不当的现象,从而加速了荒漠化的蔓延,形成恶性循环。
In recent years, the intensity of dry and warm climate and human activities has increased, resulting in the acceleration of desertification. Desertification is positively related to the intensity of economic activities and the increase of population. The increase of population has increased the pressure on land resources and water resources, and the phenomenon of deforestation, overgrazing and improper use of water resources has appeared among the low-quality population, thus accelerating the spread of desertification and forming a vicious circle.
沙漠以外地区的沙尘源也是一个不容忽视的因素。我国北方春季气候干燥,风力较强,土壤墒情差,植被疏矮,每遇大风天气,表层干燥土壤容易被风刮起,形成扬尘。而城郊地带由于破土施工、建材堆积、垃圾堆放不合理等也是扬沙的来源之一。
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