North Atlantic Oscillation Effect on the Water Levels of the Turkish Lakeland with Regard to Meteorological Indicators

Abstract

The impact of the global climate change and the North Atlantic Oscillation (NAO) on water resources in the geography of Turkey have been revealed as a result of the investigations in recent years. Big climate events have not only a direct effect on the temperature and rainfall but also have an indirect effect on the evaporation, runoff, underground storage, and sea-lake level changes depending on these meteorological parameters. In this study, it has been investigated how the level variations of the three biggest Turkish lakes (Egirdir, Beysehir and Burdur in Turkish Lakeland) are effected from the global climate change and NAO. This process will be evaluated not only with climate indicators but also with the time variations of the meteorological data. According to the results it is revealed that the meteorological parameters of Turkish Lakeland are not affected strongly from North Atlantic Oscillation. However it is found that the lake levels are affected inversely from North Atlantic Oscillation and evaporation data. Turning points were also determined by using paired t test in the early 1990s for lake level data sets. By analyzing the dimensionless data it is found that lake levels and precipitations start to decrease after the year 1985.