ИСТИНА

The most frequent among natural-technological accidents occurring in Russia are breakdowns in electric power supply systems that lead to so-called “blackouts” (accidental power outages). They are mainly caused by strong winds, snowstorms, deposition of ice, sleet, and snow, rainfalls, floods, and hailstones. Among other triggers earthquakes, hard frost, fierce heat, thunderstorms, landslides, snow avalanches, and debris flows should be mentioned. The great part of transmission facilities in Russia falls on overhead lines that are especially vulnerable to natural impacts. In general, natural triggers are responsible for more than 70 percent of all accidents in power supply systems. They occur more often in Far East, in the Southern and North-Western federal districts, and in some regions of the Central Russia, which are prone to hurricanes, cyclones, snowstorms, and heavy rainfalls accompanying by hailstones, icing, and sleet. A distinctive feature of these events is their synergistic nature, as power outages can cause a chain of other accidents at heat- and water supply, industrial plants, transport and communication facilities, producing so-called “domino effect”. A modernization of facilities, replacement of overhead lines by underground cables and protection from falling trees can reduce the problem.