عنوان مقاله [English]
نویسندگان [English]چکیده [English]
In the present study severity, duration and frequency of droughts were analyzed using monthly rain data in Lorestan province. At first, the rainfall data was normalized and then rain time series Z score was created. Dry months and periods were separated by applying run theory and by determining critical. Threshold Then, the severity, duration and frequency (SDF) curves of the droughts were plotted. By applying Markov chain, transition probability matrix and region’s static probability matrix were extracted and the number of dry years and duration of the droughts in the region was forcasted for the next 15 years. . .