چکیده:
Estimation of the magnitude and frequency of maximum instantaneous discharges and hydrographs
are used for a variety of purposes, such as the design of bridges, culverts, flood-control structures; and the
management and regulation of floodplains. Fuller (1914), developed a flood-frequency formula based on
analysis of flood peaks in hundred of streams to provide simple methods of estimating maximum instantaneous
discharges, and sought to link maximum instantaneous discharges having various average return periods to
the mean of the maximum annual discharges with a factor calibrated for different catchments. The aim of this
study is the evaluation of the mentioned method in order to estimate maximum instantaneous discharge and
calibrating its considered coefficients in Kaal Shour Sabzevar region. Therefore, the collected data from 10
hydrometric stations in the region were used in analysis and regional coefficient was obtained 0.041 and
regional inundation coefficient is from 0.88 to 2.23 in 5 to 200-year return periods. The results showed that the
discharge calculated by Fuller’s empirical formula is less than values calculated by statistical distributions.
خلاصه ماشینی:
DETERMINING OF REGIONAL COEFFICIENTS OF FULLER'S EMPIRICAL FORMULA TO ESTIMATE MAXIMUM INSTANTANEOUS DISCHARGES IN DASHT KAVIR BASIN, KALSHOUR SABZEVAR, IRAN A Salajegheh1, J Dastorani2 1- Assistant Professor, faculty of Natural resources, University of Tehran, 2- Senior expert of watershed Management Abstract Estimation of the magnitude and frequency of maximum instantaneous discharges and hydrographs are used for a variety of purposes, such as the design of bridges, culverts, flood-control structures; and the management and regulation of floodplains.
Fuller (1914), developed a flood-frequency formula based on analysis of flood peaks in hundred of streams to provide simple methods of estimating maximum instantaneous discharges, and sought to link maximum instantaneous discharges having various average return periods to the mean of the maximum annual discharges with a factor calibrated for different catchments.
Numerous applications of this method have been done in Iran and gained results have showed that Fuller formula provides more flood peaks at different return periods (Najmaee, 1990).
Arab Khedri tested the quantity of maximum observational and estimated instantaneous discharge by Fuller formula in 21 sub basins of North Alborz watershed.
Table 2: Basin coefficient (C) and regional inundation frequency coefficient (ß) in stations of region {مراجعه شود به فایل جدول الحاقی} 57 The comparison of maximum instantaneous discharge values estimated by two methods including statistical distributions and Fuller in different return periods shows that the obtained results of maximum instantaneous discharge using Fuller empirical method is less than statistical distributions method (Table 3).
In the other hand, different results obtained for maximum instantaneous discharge estimation by the method and Fuller coefficient.