Main tendencies of climate factors changes within Kuyalnik Liman drainage basin

Abstract

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.