تحليل فراواني غلظت متوسط آلاينده هاي رواناب شهري

Probability Density Function Analysis using Event Mean

Urban runoff has a large rate of various pollutants and destroys acceptor water resources and also damage environment . The management strategies for urban runoff pollutants controlling depend on identifying and analyzing these pollutants , In this study the procedure for fitting , selecting and appropriate probability distribution function (PDF) for a runoff quality constituent concentration in Isfahan was investigated. The best fitted probable distribution of pollutants concentration was determined and it was used for estimation of concentrations with different return periods. The gtimated pollutant concentration with different return periods is using Selected PDF. The results showed BOD5 and COD can be modeled by Gamma distribution , and TSS, No3, TP, Pb are statistically fitted with 2 lognormal distribution. Also, pollutant concentrations were increased with return period.