The impact of military operations in 2022 on the wind-erosion hazard of the Ukrainian right bank

Abstract

Wind erosion is caused by strong winds blowing continuously in one direction over unprotected vegetation or plant debris on the soil surface. It can be controlled by plant barriers such as forest belts. The military actions in 2022 as a result of Russian aggression dramatically changed the state of the existing network of forest belts. It was in the forest belts that the defense lines were built, which were subjected to the most intense artillery and rocket attacks and were the target of assault operations. Remote sensing methods, in particular Sentinel-2 satellite images for 2021 and 2022, were used to analyze changes in the condition of forest belts during hostilities in two research sites in Kherson and Mykolaiv regions. The Enhanced Vegetation Index (EVI) was used to determine the degree of forest degradation. The EVI index, in addition to the chlorophyll content of leaves, also responds to structural variations in the tree canopy, tree crown shape, and leaf area index. The index also takes into account the transmission of light through the tree canopy and the effect of atmospheric aerosols on brightness in the red region of the spectrum. In other words, the EVI index is very informative in terms of assessing the condition of forest belts as erosion control vegetation barriers. Studies have shown that most of the artificial forest plantations resulting from the hostilities in the spring and summer of 2022 can either perform their soil protection functions to a limited extent or are not able to counteract potential wind erosion at all. The loss of anti-erosion properties of forest belts as a result of military degradation leads to a significant increase in wind and erosion hazards. Calculations based on the WEQ methodology show that the potential volume of soil losses due to wind erosion from fields already unprotected by forest belts, plowed and without vegetation cover, increases from 3.9–4.7 t/ha per year to 7.0–8.4 t/ha per year, which often exceeds the permissible erosion rates and can lead to soil degradation and a decrease in soil fertility in the future. Post-war reforestation will take a long time, and therefore it is necessary to use fairly simple agrotechnical measures against wind erosion, in particular “conservation” tillage technologies, including no-till, which can stabilize the situation with wind-erosion soil degradation and fertility for a certain period of time.