Influence of weather conditions on the spread of fires in the forest fund of Zhytomyr Polissia

Fires are one of the critical factors in the weakening of forests. Given the high share of pine forests in the Zhytomyr Oblast, the conditions for fires are very favourable. Especially intense fires occurred in 2020, when rapid warming occurred in the spring, which in the absence of snow cover and the presence of intense winds in the February-March 2020 increased the fire danger in forests. The purpose of this study is to identify the features of the dynamics of the spread of fires in the forest stands of the Zhytomyr Oblast Department of Forestry and Hunting and assess the meteorological indicators that may affect their spread. Research methods: statistical – when analysing data on meteorological indicators and materials for accounting for forest fires. The study identified the specific features of the dynamics of fire spread in forest stands of Zhytomyr Oblast in 2014-2021. According to the analysis, there was a considerable increase in the number and area of fires in 2020 compared to the average figures for 2014-2019 and 2021 combined. During 2014-2021, 951 fires occurred on a forested area of 43,807.65 hectares. It was revealed that only 448 fires occurred in 2014-2019 and 2021, and 503 fires were recorded in 2020 on an area of 43,229 hectares. Among others, crown fires were recorded on an area of 6,389 hectares in the same 2020 year and on an area of 35.7 hectares in 2019 alone. The largest areas of crown fires were recorded on the territory of the State Enterprise “Ovrutske SF”, State Enterprise “Luhynske forestry”, State Enterprise “Ovrutske forestry” and State Enterprise “Slovechanske forestry”. The indicators of temperature, precipitation, and hydrothermal coefficient for 2014-2021 are analysed. The values of air temperature and precipitation were determined during the growing season, and the hydrothermal coefficient was calculated according to G.T. Selyaninov. The study established that the sum of air temperatures during the growing season was 3,127.6°C on average for 2014-2021. The highest temperature values were recorded during the growing season of 2018. According to the analysis of the amount of precipitation for the growing season 2014-2021, the indicators were set at 323.8 mm. The lowest precipitation rates were recorded in 2015. According to the ratio of temperature and precipitation indicators, the value of G.T. Selyaninov’s hydrothermal coefficient for the growing seasons of 2014-2021 was obtained, the average value of which was 1.04 units