Temperature-precipitation and drought analysis in Tigris basin

Increases of carbon dioxide and other gases in atmosphere due to industrial activities have caused global warming. Global warming has caused increases in extreme events such as flood and drought as well as climate changes. In recent years as a result of changes in climate, in some of countries flood disasters have occurred and in some of them increases in temperature, decreases in precipitation and drought have been seen. Drought has became one of the most important natural disaster in Southeast Anatolia Region that is devoid of vegetation. From the researches have been done, it is determined that, major part of loss in agricultural products occurred in arid and semi-arid regions during the season were because of the water deficiency. In this study that has been done as ?Analysis of precipitation-temperature and drought in Tigris Basin.? , monthly mean temperature data for long time period concerning 13 selected meteorological stations and monthly mean precipitation data concerning 18 selected stations were obtained from permanent measurement results of State Meteorological Works. In first section of this study that consisted of two sections , Thornthwaite drought indexes have been calculated and drought risk for the region has been determined according to changes in precipitation , temperature and potential evapotranspiration values that obtained from definite stations in Tigris Basin for arid term. In the second section, Enhanced Fournier Precipitation indexes and Bagnouls-Gaussen drought indexes have been determined and according to calculated index values Abrasive Power indexes that caused by precipitation have been determined for each station. In this study due to Thornthwaite drought index classification it has been determined that the place that has minimal drought risk is Bitlis and places that have maximal drought risk are Diyarbakır, Batman and Cizre. By using Fournier and Bagnouls-Gaussen methods together it is deduced that arid periods have been occurred five months June-October in one station (Cizre), four months June-September at nine stations and three months June-August at three stations. KEY WORDS : Tigris Basin, Temperature, Precipitation Index, Drought Index, Thornthwaite Method, Fournier Method, Bagnouls-Gaussen Method.