005. Факультет природничих наук

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Assessing Climate Aridity Trends in Southern Ukraine during 1991-2020
(2023) Boychenko, Svitlana; Kuchma, Tetyana; Maidanovych, Nadiia; Myronova, T.
Assessment of Climate Aridity Trends in the Southern Region of Ukraine was conducted using data meteostations for the period 1991-2020. The analysis of climate aridization trends over the past 30 years in the study region has revealed a notable intensification of this process, especially in recent years. The hottest summer months occurred in 1992, 1999, 2001-2003, 2007, 2010, 2012, and 2017-2019. These periods were marked by anomaly high temperatures, dry winds, extended non-rainfall periods, and low air humidity, often reaching as low as 30%. Over the past 30 years, from March to October, the Southern Region experienced an average of 203±6 non-rainfall days, with a trend indicating an increase by an average of 0.4±0.1 days per 10 years. Conversely, the number of days with relative humidity up to 30% on the March–October time scale averaged 41±16 days, with a tendency to increase by 1.2±0.7 days per 10 years. The highest occurrence of days with relative humidity up to 30%, on average in the region, is typically observed in July and August (7 and 10 days per month, respectively). To assess climate aridity and calculate drought severity for vegetation were used a satellite-derived Vegetation Health Index (VHI). Drought indices derived from the summed VHI values in August for the years 2007, 2018, and 2020 in the Southern Region of Ukraine are presented.
Change in the Water Surface Area of Reservoir of the Crimean Peninsula According to Radar Satellite data Sentinel-1 for the Period from October 2014 to August 2022
(2022) Kuchma, Tetyana; Boychenko, Svitlana
According to Sentinel–1 radar satellite data, there is a tendency to reduce the area of the water mirror in all reservoirs of the Crimean Peninsula, analyzed in this study, compared to their water surface area in 2015. On average, the area of the water mirror decreased by 34% in 2021. In three reservoirs, the area of the water mirror decreased by more than 60% compared to 2015: Frontove, Taiganske, and Mizhhirske reservoirs. The tendency to reduce the water surface area begins to manifest clearly in mid–2019 and continues until 2021. Also, a retrospective analysis of satellite images for 2015–2021 showed that the Simferopol reservoir of water surface area had been reduced on average by ~ 20% compared to 2015. Changes in the Water Surface Area of Simferopol and Feodosiya Reservoir for the Period from October 2014 to August 2022 were presented. A retrospective analysis of satellite images for the period from March 2015 to August 2022 showed that the Simferopol and Feodosiya Reservoirs of water surface area had been reduced on average by ~20% and ~30% (according) compared to 2015.
Climate change and fires in the Ukrainian Polissia region
(2023) Karamushka, Victor; Kuchma, Tetyana; Boychenko, Svitlana; Nazarova, Olga
Climate change accompanied by anomalously high temperatures and a decrease in precipitation during the warm season can have serious consequences for Ukrainian Polissia, including an increased risk of forest and peat fires, deterioration of ecosystem integrity, changes of biodiversity patterns, etc. An average temperature increase of 0.60°C per decade was observed in the Ukrainian Polissia region along with an annual precipitation decrease ranging from 2 to 4% over the period from 1990 to 2021. The prevailing weather conditions in 2020 included snowless warm winter, warm arid spring (in particular, in March and April), and certain accompanying synoptic conditions (e.g., high wind speeds up to 15–20 m/s). Such conditions contributed to the forest fires and a powerful dust storms in most regions of the Ukrainian Polissia. During the spring 2020, more than half of the territory of Ukrainian Polissia was exposed to fires. The climatic conditions of spring 2022 were not as dry as in 2020, however, due to the war, fires engulfed a significant part of the territory of Kyiv and Chernihiv Polissia. Analysis of the spatial distribution of the fire frequency in the regions of Ukrainian Polissia in 2020 and 2022 (based on the satellite data) points out the dominance of different fire-promoting factors: in 2020, it was weather anomalies, in 2022 - human activities (armed hostilities).
Climatic risks and forest ecosystems: the interaction between deforestation and climate change
(2024) Raichuk, Liudmyla; Shvydenko, Iryna; Kuchma, Tetyana
The article provides a comprehensive analysis of the interaction between deforestation and climate change, with particular emphasis on the impact of military actions on the reduction of forest ecosystems. The research utilized general scientific methods (data analysis and synthesis), retrospective and comparative analysis, analytical-synthetic methods (study of scientific and statistical data, archival materials, etc.), and remote sensing techniques. The aim of the study was to identify the main causes of the reduction in forested areas in Ukraine and their role in the context of global climate change, as well as their significance for the socio-economic development of the country during wartime and the post-war period. The role of forest ecosystems as a source of a wide range of ecosystem services and as a significant component of the socio-economic status of the Ukrainian Polissya region is analyzed. Special attention is given to the interaction between the reduction of forest-covered areas and the intensification of climate change. The main factors contributing to the reduction of Ukraine’s forest ecosystems are presented, with a particular focus on forest fires, including those caused by military actions. It was established that from April 2023 to April 2024, the highest number of forest fires occurred in the eastern and southern parts of the country, where active military actions are ongoing. An automated methodology for decoding satellite images to detect areas of Scots pine dieback due to infestation by the pine shoot beetle was developed, resulting in a map of the study area showing the boundaries of forestry districts, the grid of forest compartments, the contours of damaged forest areas, and new dieback hotspots. The study demonstrates that forest ecosystems are essential for mitigating climate change and ensuring sustainable regional development. This is particularly true for the Ukrainian Polissya region, especially Zhytomyr Oblast, which has the highest forest cover in the country but also leads in the loss of forest-covered areas.
Impact of climate changes on agroresources of Ukrainian Polissia based on geospatial data
(2024) Tarariko, Oleksandr; Cruse, Richard; Ilienko, Tetyana; Kuchma, Tetyana; Kozlova, Anna; Andreiev, Artem; Yatsiuk, Mykhailo; Velychko, Volodymyr
Aim. To determine the patterns of the climate change impact on the transformation of agricultural production and the ecosystem of Ukrainian Polissia in terms of time and space. Methods. Satellite and statistical data for the last 40 years (1982–2022) were used. The mean temperature for the vegetation period was defined by the sum of radiation temperatures of the terrestrial surface, calculated using the data of the infrared range (10.3–11.3; 11.4–12.4 μm) of the high-precision AVHRR radiometer of artificial meteorological Earth's satellites, NOAA, and the precipitation dynamics – using the data of ERA5 ECMWF/Copernicus Climate Change Service. The impact of climate change on the vegetation state and phenological parameters, including the beginning, end, and duration of the vegetation season, was determined by the normalized difference vegetation index (NDVI), obtained using the data of the infrared (0.72–1.1 μm) and red (0.58–0.68 μm) ranges of the AVHRR radiometer on the website of STAR NESDIS NOAA. Crop yields and the dynamics of sown areas were determined by the data from the State Statistics Service of Ukraine. The information about the dynamics of the forest cover was obtained using the Global Forest Watch satellite data. To evaluate the impact of climate change on Ukraine's forests, the investigation was conducted on burnt forest areas, using the MCD64A1 6.1 index, developed on the basis of the MODIS satellite data. Results. According to the satellite data, the radiation temperature of the terrestrial surface during the growing period increased by 2.2 ºС on average in the territory of Ukrainian Polissia over the last 40 years. There is a regional difference in the temperature regime observed in the direction from west to east. In the territory of western Polissia, the increase in the temperature of the terrestrial surface in recent decades was within the range of 1.2–1.6, and in the central and eastern parts – within 2.3–2.9 ºС. Due to the warming, the duration of the growing period was extended by 21–35 days, mostly because of earlier spring onset. There is a descending trend in the average annual precipitation amount down to 20–30 mm, which is especially notable for central and eastern Polissia. The warming was the reason for the introduction of the crops, new for this region, into the structure of sown areas, especially corn and sunflower, which had a generally positive effect on the vegetation state by the NDVI index, which increased from 0.30 in 1982–1992 to 0.36 in 2012–2022 on average. The crop yield increased accordingly, and according to the statistical data for the recent years, amounted to: corn – 7.0–9.5 t/ha, winter wheat – 4.5–5.0, and sunflower – 1.5–2.0 t/ha, which is close to the level of their yield on chornozem. At the same time, due to climate change and the transformation of agricultural activity, there has been a higher risk of deterioration in the ecological state of typical Polissia landscapes, droughts, and soil degradation. According to the results of the analysis of twenty-two years of the dynamics in forest fires, the largest areas of burnt forests were registered in 2012 (694.30 sq.km), 2015 (1,078.81 sq.km), and 2020 (776.27 sq.km), which demonstrated the increase in fires during the recent decade along with the tendency towards longer fire hazard period. Conclusions. The increase in the temperature of the terrestrial surface of the Ukrainian Polissia during the growing period and the lengthening of the growing period created the conditions for corn and sunflower to be introduced into the arable areas, which had a positive impact on the vegetation state index, NDVI. As a result of these transformations both in the sown area of these crops and their yield, Polissia is becoming a new grain-oil belt of Ukraine. Concurrently, there are higher risks associated with maintaining high performance of agroecosystems and the increase in the risks for soil degradation processes, the deterioration of the ecological state of wetlands and forests, as well as drying-out of small rivers and lakes. Balancing the high yield of modern agroecosystems and safe nature management requires systemic measures in adapting the agricultural activity and nature management to new climatic conditions, which requires implementing the management of soil, water, and bio-resources, achieving optimal parameters of fertility for mineral and peaty-swampy soils. Reconstructing current land reclamation systems to optimize water regimes for the agricultural lands and protect typical Polissia ecosystem is needed.
Wildfires and Climate Change in the Ukrainian Polissia During 2001–2023
(2025) Boychenko, Svitlana; Kuchma, Tetyana; Karamushka, Victor; Maidanovych, Nadiia; Kozak, Olena
Climate change, accompanied by anomalously high temperatures and a decrease in precipitation during the warm season, can have serious consequences for the ecosystems and sustainability of the Ukrainian Polissia. In particular, there are increased risks of forest and peat fires, as well as an overall deterioration of the region’s ecological condition. Between 1990 and 2021, the Ukrainian Polissia region recorded an average temperature increase of 0.60 °C per decade, along with a 3–5% decrease in annual precipitation. An analysis of the spatial distribution of wildfire incident density based on satellite data (FIRMS) in the regions of the Ukrainian Polissia from 2001 to 2023 highlighted several periods of sharp increases in fires: 2002, 2007–2009, 2014–2015, and 2019–2020. The Spring Fire Season and the Late Summer–Autumn Fire Season coincide with periods of reduced precipitation, which in some years reached 40–60% below the climatic norm. Although the climatic conditions of spring 2022 were not as warm and dry as those in 2020, significant parts of Kyiv Polissia and Chernihiv Polissia suffered from large-scale wildfires due to ongoing military actions. The spatial distribution of fire frequency in 2020 and 2022 highlights different contributing factors: in 2020, weather anomalies were the primary cause, while in 2022, armed hostilities played a key role. Military conflicts not only increase the risk of fires but also complicate firefighting efforts, making the region even more vulnerable to large-scale forest fires, and thereby threatening its sustainability. These findings underscore the urgent need for integrated fire management strategies that take into account climate change, land-use policies, and geopolitical factors to mitigate the escalating wildfire threat in the region and ensure long-term sustainability.

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