Frequency Analysis of Minimum Flow Rate and Maximum 24-hour Precipitation By Gambel and Log Pearson Type 3 Methods in the Kamal Chai River (Southern slopes of Sabalan)

Frequency analysis of events is a set of methods that, using probability rules, investigate the probability of a phenomenon’s repeat over time. The purpose of these analyses is to obtain the period of return of measured events and to estimate the value of an event for a specified return period, which is outside of the scope of registered events and is used to design the projects. Gombel (1) and Log Pearson (3) methods are among these analyses. In this paper, using these two methods, we investigate the probability of occurrence of minimum of volume flux and maximum of daily rainfall in the Kamal Chai Basin in the south of the city of Sabalan. In addition, the Maxus formula (3) has been used to secure data adequacy. According to these surveys, the precipitation less than 44 mm in 24 hours is of a probability of 96%. And likewise, the volume flux will be higher than 1.12 cubic meters per second by 95%.