Rahim Kazemi; Amir Safari; Amir Karam; Jahangir Porhemat
Abstract
Estimation of Base Flow Index (BFI), has always been one of the most important issues in hydrology. Base flow separation process, often is done using daily stream flow data. Lack of full coverage of daily data for the whole country, may lead to some errors for estimating the base flow and its index. ...
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Estimation of Base Flow Index (BFI), has always been one of the most important issues in hydrology. Base flow separation process, often is done using daily stream flow data. Lack of full coverage of daily data for the whole country, may lead to some errors for estimating the base flow and its index. In this research, base flow index in some catchments of Karkhe basin based on daily and monthly stream flow data and using six algorithms were extracted. Three based on recursive digital filter (One-parameter, two parameter and Lynie & Hollick algorithms), and the others on simple smoothing including, Local minimum, Fixed interval and sliding interval methods. Results were analyzed using different statistical methods such as standard deviation, mean absolute error, relative error and other descriptive methods. The results showed that minimum relative error of monthly data compared to daily data was related to two parameter algorithm with 2.45% and the maximum was related to Lynie & Hollick algorithm with 84.19 percent .In overall conclusion, two parameter algorithms because of low relative error, minimum Mean Absolute and Root Mean Square Error was recognized as a suitable method for the extraction of base flow using monthly data in the absence of appropriate data daily.
Alireza Habibi; Amir Safari; Amir Karam
Abstract
Process erosion is one of the most important degradation process, particularly in semi-arid climate. Identify the sediment of the issues is important for watershed managers and planners. The main purpose of evaluating and comparing the potential contribution of this research has been deposition of marl ...
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Process erosion is one of the most important degradation process, particularly in semi-arid climate. Identify the sediment of the issues is important for watershed managers and planners. The main purpose of evaluating and comparing the potential contribution of this research has been deposition of marl formations. This study was conducted in hablerood basin and in the northern city of garmsar. for this reason, constructive map lithological was prepared as a unit in geographic information systems.then, the potential value erosion on sediment collected simulators rain comforts' with intensity4mm and continuing 10 minutes in the category marl and none marl has been determined. the results showed that in hablerood basins contribution marl and none marl land respectively59.4 and 40.6 percent. While in terms of lands area. marl and none marl land respectively 21.4 and78.6 percent.particularly sedimentation marl lands was 2.38 ton in hectares, that twice none marl land.this study showed that the use of simulators rain in order to determine the contribution of sediment formations suitable method for watershed planners, to estimate the erosion rate is correct.