Assessment of Climate Favorability for the Grain Cultivation Based on the Frequency of Severe Droughts

V. N. Pavlova, A. Yu. Bogdanovich, and S. M. Semenov

Using climate monitoring data from 96 Russian weather stations, the years of severe droughts are identified. For this purpose, the following criterion was used: a value of the Selyaninov hydrothermal coefficient for May–August is less than 0.6. Climate of a time period, i.e., a set of consecutive years, is considered unfavorable for the cultivation of grain crops if the frequency of severe droughts p (the Bernoulli distribution parameter) exceeds 0.5. This parameter is estimated from data of the considered weather stations separately for the time periods of 1976–1997 and 1998–2019 based on the number of the identified severe droughts. The probability that p > 0.5 is estimated, and the corresponding schematic maps are constructed for both time periods. The highest probability is obtained for the stations located in the Astrakhan, Volgograd, Saratov, and Orenburg oblasts, the Republic of Kalmykia, and the Republic of Crimea. At the same time, a noticeable increase in this probability in the second period relative to the first one is found for the Volgograd and Saratov oblasts.