Dust storms
Nature
During wind erosion, the finer soil particles, when set in motion by the wind, are quickly carried upward, sometimes to great heights, by turbulent air currents, and are transported in suspension as a powdery dust. Under suitable conditions this may result in a dust storm, which may travel long distances. There are two essential requirements for the initiation of a dust storm. Wind speed at the ground must exceed a certain critical speed, ranging between 13 and 30 mph depending on the shape, size, specific gravity, dampness and temperature of the ground particles.
Incidence
Dust storms are, at the least, disagreeable, but may also cause considerable damage. People in villages, towns, and cities as well as rural inhabitants undergo inconveniences and sometimes serious illness or suffocation. Fences, ditches, and channels are blocked or buried and farmsteads are rendered uninhabitable. Grass, trees, shrubs, and hedges may be smothered or buried. Insects and weed seeds are often carried to clean fields. Railways and roads are sometimes blocked by dust. Covering of established crops or pasturage by drifting dust may result in crop damage. Dust storms have other serious consequences in obstructing vision and in causing soil erosion, electrostatic discharges and radio static.