Evaluation of drought situation and its process in Kermanshah region on the basis of drought statistical indexes

Drought is one of the natural disasters that inflict serious damages of human life and natural ecosystems. It has the gradual effect during a relatively long- term periods, impossibility of determining its exact beginning and end, and the geographic extent of its impact. In the other hand, the lack of an exact and acceptable universal definition of drought has mad this phenomenon complicated. precipitation is the most important parameter that is used for defining drought and its lack or deficit implies the threshold of drought. In this paper, considering 24 year of rainfall data from 5 stations (1988- 2011), drought in Kermanshah region has been evaluated on yearly basis. At first the homogeneity of data was evaluated using run test method. Then drought was explained on the basis of fallowing indexes, percent of normal index and standardized precipitation index. The both of indexes, the most intensity drought and wet were seen order to years 2008 and 1994. However extremely and severely drought periods were not so much in study region

کلیدواژه ها:

drought ، percent of normal precipitation index ، Standardized Precipitation Index ، Kermanshah province