TITLE:
Automated Baseflow Separation and Estimation of Groundwater Recharge Using Master Recession Curve Technique in the Sissili Basin
AUTHORS:
Kouakou Valentin Koffi, Emmanuel Obuobie, Donissongou Dimitri Soro, Stefan Wohnlich
KEYWORDS:
Baseflow Separation, Digital Filter, Automated Master Recession Curve, Flashiness Index, Groundwater Recharge, Sissili Basin
JOURNAL NAME:
Open Journal of Modern Hydrology,
Vol.16 No.2,
March
13,
2026
ABSTRACT: The accurate estimation of baseflow and groundwater recharge is key to effective groundwater resources management. Both groundwater recharge and baseflow have been widely used in calibrating hydrological and groundwater models. This study aimed to estimate groundwater recharge and baseflow in the Sissili River basin, a subcatchment of the White Volta Basin in Ghana, using the recession curve analysis method and digital baseflow separation filters. Six different digital filters or methods from four tools were used to estimate the baseflow. An attempt was made to test the performance of the baseflow filters during the dry seasons and recession periods, while recharge estimation was based on the hydrograph recession method. The recession curve analysis yielded recharge rates ranging from 29 mm to 68 mm, accounting for 3% and 9% of the annual rainfall in 2004 (971 mm) and 2005 (761 mm), respectively. The estimated average recharge was 47.3 mm for the period 2003-2008, representing 5% of the average annual rainfall of the period, which was 949.6 mm. The estimated yearly baseflow, based on the six methods, ranged from 19.1 to 69.8 mm, or from 2% to 7% of the annual rainfall.