Hydro-meteorological hazards and accidents at overhead power lines

The electric power industry is a key branch of the Russian economy, providing production, transmission, distribution, and consumption of electrical energy, thereby creating the basic conditions for the functioning of the entire economy of the country and the life support of its population. Overhead power lines are mostly exposed to the impacts of various natural hazards and phenomena, especially those of hydro-meteorological genesis. Accidents and emergency situations with power outages triggered by natural hazards and adverse phenomena account for more than a half in the total number of natural-technological accidents registered in the author’s database. The vulnerability of power transmission networks is caused by their large length, covering the entire economically developed territory of the Russian Federation. Throughout their course, power lines inevitably fall into the area of activation of hazardous natural processes and phenomena. The paper aims to reveal regional differences in the accident occurrences due to hazardous natural impacts on power transmission lines, identify principal hydrometeorological factors of these accidents, and find out regions most at risk. The methods used are the geographic and statistical analysis of the information collected by the author in an electronic database on technological and natural-technological accidents and emergency situations. The majority of natural-technological accidents with a power failure are caused by wind loads, which are especially dangerous in combination with other hydro-meteorological factors such as rain, snow, ice and frost deposit, thunderstorm, and hail.