No abstract

The intensive use of water resources and the transformation of natural landscapes under the influence of human economic activity have led to changes in the natural water balance of river drainage basins. The negative processes thereof are intensified by climatic changes that have significantly disturbed the hydrological regime, determined by changes in water content and river flow dynamics. The retrospective study and prediction of the flow of the Dnieper River was carried out using multivariate statistics and adaptive methods of nonlinear time series analysis. The anomalous features were identified and the main periods of changes in the water regime of the river for 190 years (1818-2008) were determined using the standard root-mean-square deviation and wavelet analysis. As a result of non-linear prediction, it was determined that if the tendency of anthropogenic and climatic formation of the water regime of the Dnieper River sustains, there is a 90% probability of insignificant but steady trend and cyclical reduction of the average annual flow by 1.6 m 3 /s per year to 1120 ± 270 m 3 /s by 2040. The results of the detailed retrospective analysis for 190 years and the prediction of the probability of changes in the flow of the Dnieper river confirm the previous conclusions of many scientists regarding the significant transformation of the ecosystem of the transboundary river and provide new knowledge regarding the main stages of formation of the water regime and the probability of further regulation of the flow of the Dnieper river if the current conditions of the negative impact of economic activities are maintained in the transboundary basin.

To increase the level of management efficiency in the agricultural sector of the economy, it is necessary to substantiate environmental protection measures for the restoration and rational use of natural resources, to ensure the implementation of the sustainable environmental management principles, considering the spatio-temporal patterns of changes in climate and bioclimatic potential of the territory. Using the methods of multivariate statistics and time series forecasting, regularities of changes in climatic conditions in the Steppe zone of Ukraine for 1945-2019 were established, and a forecast of changes in the bioclimatic potential of the region until 2030 was made. It was established that during the research period the average annual air temperature increased by 3.5 °C. The amount of annual atmospheric precipitation varied within 186-778 mm with a variation level of 27.2%, in the last 20 years it was determined to decrease by 40% -to 500-300 mm. It has been proven that the inertial probability of repeating hot years is estimated at 0.58, and the possibility of repeating wet years at 0.46. As a result of forecasting, it was determined that if the trend of climatic conditions is maintained, there will be a stable trend-cyclic increase in the average annual air temperature by 0.06 °C per year and a decrease in the amount of annual precipitation by 62.0 mm per year. This resulted in an 18.7% increase in solar radiation on the soil surface and a 26.0% decrease in climatic losses on soil formation, which reduced the rate of the natural ability to reproduce soil fertility. In particular, the bioproductivity of plants decreased by 62.0%, and the probability of its further decrease by 20% is predicted. Over the past 20 years, the coefficient of natural humidification has decreased by 66.4%, and it is predicted to decrease by 20%. The obtained results confirm significant climatic changes and their negative manifestations on the reduction of bioclimatic potential in the Steppe zone of Ukraine, the deterioration of agricultural production conditions, the reduction of harvests, the self-regenerating and self-regulating function of steppe soils.

The decrease in the agricultural efficiency is associated with the influence of wind erosion, the consequence of which is a decrease in the soil fertility. Significant effects of wind erosion are typical of the arid and semi arid zones with a small amount of precipitation, high air temperature and degree of evaporation, reinforced by strong winds and low differentiation of plant protection. It has been proven that the intensity of the effects of deflation processes depends on the physical and geographical conditions of the distribution of agricultural land, systematic soil protection activities and the availability of vegetation. It has been established that the acceleration of the deflation processes occurs in the territories with increased anthropogenic pressure, which leads to ecological disturbance of the natural balance characterizing territorial ecosystems. In the course of the studies it was found that the natural processes of wind erosion are significantly enhanced by the absence of a scientifically-based and ecological land development system of agriculture, which leads to destruction of the soil cover, reduction of soil fertility, damage to the agricultural crops and, thus, the economic damage. As a result of application of the GIS and ERS technologies, the empirical-statistical model of the possible soil loss due to wind erosion in the territory of the Steppe zone of Ukraine, it has been found that in the course of the deflation processes in the territory taken by naked fallow upon the absence of the conditions for the deflation resistance activities, the value of soil loss at the epicenter of dust storms can reach about 600 t / ha. Studies proved the importance of the deflation resistant action of the vegetation cover, which tends to an increase in the erosion dangerous (favorable) areas of agricultural land by 1.7 times, which reduces the soil loss by 5.62 times. In accordance with the intensity of the effects of the deflation processes and the increase of the soil losses, the contour and land development deflation resistance activities with elements of soil protection agriculture were proposed.

Background: The directed climate change is one of the most important global challenges of the XXIst century, which is beyond the scope of scientific research and makes a complex interdisciplinary problem. Methods: The object of study is the long-term changes of climatic conditions in the southern subzone of the East European Plain steppe. The subject of research is the temporal regularities of climatic parameters development (air temperature, total amount of precipitation). Results:The results of processing and forecasting changes for long-term climatic indexes parameters (ambient temperature and precipitation) that reflect the age-long rhythm of the of steppe ecosystem development of the East European Plain southern part. Using the multivariate statistics the regularities of long-term climate dynamics are obtained. The main rhythms are specified, the abnormal manifestations, the main time period changes and the functions of climate indicator provision are determined. The probabilities of annual inertia and periodic climatic changes using Markov networks are calculated. Conclusion: The highly accurate prediction of climate change is implemented on the basis of nonlinear multilayer artificial neural networks.