Scrutiny of Base Flow Separation Using Natural Monthly Discharge

In hydrology studies, natural river regimes are considered while this assumption is not correct because the water of the river is using for developing agriculture, industry, and other needs, particularly in the middle basins. The requirement for river base flow separation is having access to natural river regime on a daily scale, which regarding the limitations of naturalization, natural river regime can be calculated in the annual or monthly scale. Because of this issue, the estimation of base flow has been faced with some difficulties. On the other side, due to the complex relation of surface water with groundwater, the estimation of base flow is too hard. Therefore, in this study, the removal process method was used for naturalizing monthly discharge of Belbar basin, and Eckhart RDF algorithm, because of considering aquifer characteristics for calculating base flow and ability to optimizing its parameters, was used. The parameters of return constant and the maximum base flow index for monthly natural river discharge in hydrometric stations of Belbar dam was optimized. Then, the monthly base flow was calculated and the results showed that the monthly natural river discharge can be used like the daily natural river discharge with the same accuracy.