Compare Standard Precipitation Index and TOPSIS ranking method to assess the drought adventure Condition in Khouzestan province

The drought status studies as a natural hazard in different areas in order to develop plans to deal with drought and risk management is very important. They are lots of indices for drought assessment which based on climatic effective quantities. Check simultaneously occurrence situation of drought indices categories can be a useful framework for conformity assessment profiles. The aim of this study was to compare two methods, TOPSIS ranking method and standardized precipitation index (SPI) for drought condition in Khouzestan province and their performance in this review. In another part of the study, the sensitivity of TOPSIS method to determine that which of four climatic parameters are affecting climate drought or wet has been done and provided as tables. In this study it is found that these two methods to determine the intensity and condition of drought, are good and have similar performance but for measure the intensity of wet, standard index (SPI) isn’t useful. In fact, This method just determine that, the target year is wet or not. For example, the lowest value for this index was -3.04 which is related to Abadan station at 1390 and this number indicates severe drought, also the highest value was 1.33 which is related to Ahwaz station so it located in normal (wet) category. TOPSIS ranking method in addition to determine the intensity of the drought, also can present the condition of wet years numerically. According to calculations, 1390 was the driest year between all stations and 1371 was the wettest year for all stations. Also, To determining The sensitivity of TOPSIS method, it was found that the most sensitive parameter among the climatic parameters, related to the number of rainy days and low sensitivity is for relative humidity between all the parameters.