Saman Javanroodi; Mohammad Mahdavi; Baharak Motamedvaziri
Abstract
In order to determine the role of hydrological statistic data periods on flood forecasting in Sefidrood Watershed, maximum daily flows were collected from hydrometric stations, thus seventeen valid stations with long-term statistical data period was chosen and in some cases which data were corrupted, ...
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In order to determine the role of hydrological statistic data periods on flood forecasting in Sefidrood Watershed, maximum daily flows were collected from hydrometric stations, thus seventeen valid stations with long-term statistical data period was chosen and in some cases which data were corrupted, data has been reproduced by considering common time base.. At the second step, maximum daily flow data have been divided in to statistic series with 10, 15, 20, 25, 30 and more than 30 years data periods. Fitting statistic distribution of Normal, Normal log, Normal log 2 parameters, Normal log 3 parameters, Pearson log 2, Pearson log 3 and Gamble were determined by “Smada” software, also flood with two, three, five, 10, 25, 50, 100 and 200 return periods were calculated either. Statistic distribution for all of seventeen hydrometric stations were determined separately with RMSE method in Excel and SPSS for maximum daily flow.. Regarding zero-error in forecasted floods for long statistic data period (more than 30 years) in related return periods, compared with short statistic data period (10, 15, 20, 25 and 30 years), flood’s estimated error was calculated for all stations. In general, results indicated that increasing of statistic period, will enhance the accuracy of forecasting in hydrometric stations, and applying short-term data period will result in high levels of error.
Hiwa Osmani; Baharak Motamedvaziri; Abolfazl Moeni
Abstract
The purpose of this study is to test the efficiency of the Soil and Water Assessment Test (SWAT) and its applicability as a flow simulator, and using SWAT-Cup software and the SUFI2 algorithm as a means to calibrate and validate Tehran’s Latyan Dam upstream area. In order to test the efficiency ...
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The purpose of this study is to test the efficiency of the Soil and Water Assessment Test (SWAT) and its applicability as a flow simulator, and using SWAT-Cup software and the SUFI2 algorithm as a means to calibrate and validate Tehran’s Latyan Dam upstream area. In order to test the efficiency of this model in simulating output discharge, by comparing Roodak hydrometric station simulation values situated at the exit of the area during an 11-year period (1997-2007), it was specified that the model did not perform well in simulating Bik discharges. Further on, at first, 21 effective flow parameters were entered into the SWAT-Cup software, which after analyzing sensitivity, 14 parameters were used for calibration and validation. Calibration was carried out for years 1997 to 2003, and validation was conducted for years 2007 to 2007. Different assessment indexes were employed to measure performance of the model in SWAT-Cup software and the SUFI2 algorithm, which indexes R2, NS, P-Factor, and R-Factor for the calibration period were 0.91, 0.88, 0.96, 1.79, and values for the validation period 0.92, 0.92, 0.9, and 1.54, respectively. Moreover, the Alpha coefficient for underground water, surface water delay coefficient, and soil outward density were recognized as the most sensitive parameters in output discharge.
