Repetition the drought types of weather in Kharkiv region

The state of the atmosphere with a long period without rain, associated with high temperatures, low humidity, high winds is a characteristic feature of the temperate climate, which creates unfavourable conditions for various spheres of human activity. Atmospheric and soil drought, hot dry winds, dust storms cause damage to agriculture, energy, transport and other sectors of the economy, as well as population. The drought phenomenon analysis of the space-time structure in Kharkiv region and definition of dry type distribution of eather complex are examined. Having analyzed the statistical data of hydro-meteorological conditions in Kharkiv region in 1975-2014 years, it has been shown that the longest of the drought types of weather complex are observed every three years, catastrophic types are observed every 10 years. The temporal distribution of the drought weather complex types and placement of hierarchical levels has been studied with methods of mathematical statistics and, in particular, cluster analysis. Using cluster analysis, the objects were placed on hierarchical levels with three groups of clusters, separated in groups of years, which corresponds to most types of dry weather complex. Analysis of aridity categories distribution in Kharkiv region has showed that the average frequency of weak drought phenomenon occurrence is 40-45%, middle 30%, intense 15%, very intense 10%. The analysis method of the arid phenomena space-time structure unifies meteorological characteristics of these years and can be used to perform specific tasks in various industries.