Problem. Global climate changes, which are observed over the last decades, influencing the formation of modern hydrological regime of the Kuyalnik Liman. In the paper for the detection of major trends of these changes the natural climatic factors (temperature, precipitation) are evaluated. The purpose of investigation is assessment of changes in major climatic factors of flow formation, namely precipitation and air temperature for the year, warm and cold periods on the basis of meteorological stations data within the catchment the Kuyalnik Liman and adjacent areas during the period 1900-2012. Research methods are methods of statistical processing of the initial information. Analysis of changes in climatic factors was occurred on the base of comparing data before and after year 1989 (beginning of observations - 1988, 1989-2012). Main results. The average annual temperature for the period 1989-2012 on the all the weather stations are increased from 0,8°C (Rozdelnaya) to 1,1°C (Odessa, Lyubashevka) compared with the previous observational period (1951-1988). During the warm season - from April to October – on all the weather stations average temperature are increased on 0,7°C, on the station Odessa - on 1,0°C. In the period 1989-2012 from November to March on all the weather stations the average temperature are increased on 1,0 - 2,0°C (relative to the previous estimated range). On chronological graphs of average year temperatures, in the warm and cold seasons upward trend in air temperatures are marked. In the cold period transition in average temperatures from negative to positive means are eventuated. Data review on all the meteorological stations revealed that temperature trends for the year, warm and cold periods are characterized by statistically significant correlation coefficients. For the average annual precipitation for the period 1989-2012 statistically significant trends are not found. In the cold period reducing of the amounts of precipitation are dominated, in the warm period growth tendencies are observed. Conclusions. Trends in changes of climatic factors on the watershed the Kuyalnik Liman indicate the unfavorable conditions of the flow formation. Rising of air temperatures of cold season promote the thaws formation and reduce the discharge and volume of spring floods. Increasing of air temperatures of warm period led to growth of evaporation from the land surface, especially from water surface of reservoirs. These losses are not recompense by the increasing of precipitation. So, on the catchment the Kuyalnik Liman climatic conditions that reduce the water resources are formed.

The analysis of current scientific work on the use of statistical methods in hydrochemical research has shown that this approach is sufficiently substantial, both in Ukraine and abroad. The purpose of this work is to determine the main statistical parameters and to research the possibility of applying theoretical laws of distribution to the time series of water mineralization.This research presents the results of the application of standard statistical methods of hydrometeorological information processing for data on water mineralization at 28 gauges of the Dnipro basin (within Ukraine) for the period from 1990 to 2015. The dynamics of the obtained statistical parameters (long-term annual average, coefficients of variation, asymmetry and autocorrelation) within the Dnipro basin in Ukraine has been analyzed. The average annual values of mineralization vary substantially within the studied part of the Dnipro basin - in the northern part the maximum value of the annual average mineralization is 447 mg/l, as it moves to the south, the mineralization increases and in the sub-basin of the Middle Dnipro it reaches a maximum of 971 mg/l; the highest values are observed in the south (sub-basin of the Lower Dnipro), where they can reach extremely high values for particular small rivers (the Solon River - Novopavlivka village, 3356 mg / l). The long-term variability of mineralization in the rivers of the studied area is insignificant, and the autocorrelation coefficients of the mineralization series are quite high, in most cases they are significant and tend to decrease from the sub-basin of the Prypyat’ river in the north to the sub-basin of the Lower Dnipro river in the south. Within the framework of the presented research, the possibility of using theoretical distribution curves known in hydrology to describe the series of river mineralization, using the example of the Dnipro basin, has also been analyzed. Using Pearson’s fitting criterion, the Pearson type III distributions and the three-parameter distributions by S.M.Krytsky and M.F.Menkel have been verified on their correspondence with the empirical series of mineralization. As a result, it was found that in 85% of cases the Pearson type III distribution can be used, and the three-parameter by S.M.Krytsky and M.F.Menkel can be used in 60% of cases.