Variations in the precipitation and stream flow depending on North Atlantic oscillation at GAP region

Yetmen, Hurşit, Variations In The Precipitation And Stream Flow DependingOn North Atlantic Oscillation At GAP Region, Master?s Thesis, Advisor: Assoc.Prof. hsan Çiçek, 62 p.ABSTRACTIn this study, the relationships between the North Atlantic Oscillation(NAO) and precipitation and stream flow in GAP region, have beeninvestigated. Recording period of meteorology stations, that used in this study,changes between 47 and 76 years. Monthly total precipitation data is obtainedfrom Turkish State Meteorological Service and flow data is obtained fromGeneral Directorate Of State Hydraulic Works. Multiple linear regressionmethod was used to determine which one of the 0, -1, -2 or -3 months is themost related with monthly variations in the precipitation and stream flow datain the period of November-April months. As a result, in the GAP region, anegative relation was obtained between precipitation and the winter NAO indexmapped for each months. This negative effect is closely related with the positiveNAO index in the considered period of this study. As the variations inprecipitation, that in stream flow tend to be decreasing.In this study, it is determined that generally there exists a negativerelation between precipitation and stream flow with winter NAO index. Thisrelation is also more apparent in March and April with respect to the othermonths.