V.P. Evstigneev 1, 2, V.A. Naumova1, M.P. Evstigneev2
1 Institute of Natural and Technical Systems, RF, Sevastopol, Lenin St., 28
2 Sevastopol State University, RF, Sevastopol, Universitetskaya St., 33
The article focuses on frequency of dangerous meteorological events in Sevastopol region with special emphasis on heavy precipitation events. The analysis of the frequency of occurrence of dangerous meteorological events, intra-annual distribution and occurrence of their types was performed using the data of two stations (“Sevastopol” and “Chersoneses lighthouse”) on the territory of Sevastopol during the period 1976-2018. The study of statistical properties of extreme precipitation distribution by block maxima approach was carried out and frequency distribution functions of annual maximum rainfall amounts were obtained. For this purpose, a sample of annual maximum rainfall amount at two stations for 1936-2018 was formed.
In addition, a study of heavy rainfall profiles was carried out. The “rain profile” refers to the relative change in precipitation intensity during rainfall. In order to get profiles, 115 individual rain events with the amount of precipitation above 10 mm were identified from pluviograph records at “Sevastopol” station (1994-2018). A set of profiles was typified by precipitation intensity distribution using the k-medoid clustering algorithm, which is a robust analogue of more common k-means clustering. As a result, three types of rain intensity distribution (i.e. “profiles”) were obtained.
The final part of the article describes a case of heavy rainfall on the 7th of June 2019 resulted in registration of the record-breaking daily precipitation amount at one of the two stations of the region. In particular, it describes the synoptic situation of the rainfall as well as the damage caused to the population and economic sectors on the territory of the Republic of Crimea and Sevastopol during the evolution of the atmospheric process.
Keywords: dangerous meteorological events, precipitation, extreme value distribution, rainfall profile, Sevastopol region, climate change.
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