Part of #Drought and determining its period and its relationship to development# :
Publishing year : 2015
Conference : The 2nd National Conference on Water Ways in Iran and the Middle East
Number of pages : 4
Abstract: Due to the importance of drought and its effects on all aspects of life and various sections of society, specially thechanges of natural environment, in this paper for the city's rivers we have selected multi-variables models, time series of first grade auto regressive model and then according to that, a population of hundreds of series of five hundred years is established. Inconsidering this population and also the 20, 50, 100, 200, 500 periods for artificial populations made the drought period arespecifiedcriterion is the Yevjevich model which infact is the same as the classic analysis of deficiencies. But in second methodFerick .et .al which is the same as the first one, but it has only one additional condition for the end point of the dry period. Itmeans that the average in the final year and also the average calculated after three years should be more than the average calculated as total average. Moreover, with the help of these periods, and also considering three parameters – the length of the shortage period, the volume of shortage and the rate of deficiency – and also with the help of the dryness for thirty five periods, the results are presented.