TY - JOUR JF - JSTNAR JO - jwss VL - 15 IS - 57 PY - 2011 Y1 - 2011/10/01 TI - Comparison of Baseflow Index in Hydrograph Separation with Different Methods in Some Rivers of West Azarbaijan Province TT - مقایسه شاخص جریان پایه در روش‌های مختلف تجزیه هیدروگراف جریان در تعدادی از رودخانه‌های استان آذربایجان غربی N2 - Baseflow separation has long been an important topic in hydrology and has a crucial role in water resources management in arid and semi arid regions like Iran. In this paper, a comparison among commonly used automated techniques for hydrograph separation including theoretical method of local minimum and digital filter of one parameter with different filtering parameters of 0.9 to 0.975 and two parameter methods was done to estimate baseflow using baseflow index. For this purpose, daily flow data in some stream gauging stations in west Azarbaijan province were used. For comparison, in addition to baseflow index the graphical method based on the observed daily flow data and correlation coefficient among them was utilized. The main aim of this research is distinguishing the most suitable method in hydrograph separation and estimating the baseflow. Results showed that in different methods baseflow largely contributes to streamflow and also has high fluctuations. However, the results of the digital filter with two parameters appear to be hydrologically more plausible than those of the other methods, but the results of digital filter with proper parameter - in this region one parameter method with filter of 0.925- has proper estimation accuracy. Also, the baseflow index based on method of two parameter digital filtering varies from 0.54 to 0.78 in this study area. SP - 219 EP - 228 AU - M. Teimouri, AU - M.R. Ghanbarpour, AU - M. Bashirgonbad, AU - M. Zolfaghari, AU - S. Kazemikia, AD - KW - Baseflow KW - Hydrograph separation KW - Baseflow index KW - Recursive digital filter KW - West Azarbaijan Province UR - http://jstnar.iut.ac.ir/article-1-1871-en.html ER -