Annual Baseflow Estimation by Combining Hydrological Models and Graphic Hydrograph Methods

Abstract

Streamflow consists of runoff, interflow and baseflow which is reflected / illustrated in the river flow hydrograph. Predicting the interflow and baseflow in a catchment is important for the water resource management, specifically to find out the relationship between groundwater with surface water and ground water potential. Although, baseflow analysis according to some researchers produces uncertainty, due to difficulties in measuring baseflow. In the hydrological cycle, the relationship between precipitation, evapotranspiration, runoff, recharge, interflow, percolation, groundwater storage changes, baseflow and streamflow is described in hydrological model. In this study, a simulation of the hydrological model above, evapotranspiration and runoff was analysed by the tank method, the recharge was analysed by using equations from previous researches, using precipitation data in 2011-2015. In addition, the analysis of interflow and baseflow was performed by using graphic hydrograph comparative method from the years 2011-2015 discharge data on catchment in Katulampa, Bogor, Indonesia. The results showed that streamflow is the same as baseflow at the end of the dry season in August or September or October. The annual flow of the model is smaller than the baseflow with the UKIH , HYSEP and PART hydrograph separation methods. The interflow value is 7 % and the baseflow is 53% from the precipitation in a year.