Drought is one of the physical hazards, that since time has caused serious changes in the human life. Drought is divided into three types: Climatic, Hydrologic and agricultural. the aim of this paper is recognition and finding of relationship between climatic and hydrologic drought. According to above mentioned research methods the recognition of severity drought and relation between both climatic and hydrologic drought have been done by using data set of climatic and hydrometric stations in the Qazvin plain. In this Study at first drought indices are briefly discussed and then by using of deciles method, severity and duration of drought in both climatic and hydrologic conditions have been obtained .The results of research show that number of droughts are more than number of wet years, or, negative anomalies of precipitation, water table and discharge are more than positive anomalies .In recent years-drought years- human activities are main factor in decrease store of water table and hydrologic droughts have a lag time related to climatic droughts.
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