Characterised by sandy soils with long drought periods, these areas can get to be very extensive. The insulators are mainly affected by wind-borne contamination and face unique challenges. Natural cleaning may occur during frequent periods of rain or by “sandblasting” in high wind conditions. Infrequent rainfall, combined with the slowly dissolving salts in this type of pollution, makes natural cleaning less effective.
Critical wetting, which poses a risk to insulator contouring, can occur relatively frequently in the form of dew on insulators. The dry and dusty conditions can cause the accumulation of fine sand or dust particles on the surface of the insulators, compromising the insulating properties and creating conductive paths, what leads to flashovers.