Groundwater recharge estimation using empirical methods from rainfall and streamflow records

Abstract

Study region: Gumara and Ribb watersheds, Abbay Basin, Ethiopia. Study focus: In this paper, an attempt was made to estimate groundwater recharge from streamflow and rainfall records. The groundwater recharge was estimated by different empirical methods, including the water balance method. The Ribb and Gumara rivers streamflow data were collected from the Ministry of Water, Irrigation, and Electricity of Ethiopia for estimating groundwater recharge by using baseflow separation techniques. The climate data was obtained from the Amhara National Meteorology Agency for estimating rainfall recharge and water balance components. New hydrological insights for the region: Groundwater resource development needs the determination of groundwater recharge volume. The annual areal rainfall, reference evapotranspiration, and recharge from rainfall of the study area were estimated as 1399.8 mm, 1300.21 mm, and 253.70 mm, respectively. The evapotranspiration was determined using the Penman-Monteith method. The baseflow separation techniques of RORA, PART, WHAT, and RECESS were employed during this study. The recharge coefficient estimated from rainfall and streamflow data were found at 0.18 and 0.20 respectively, which indicated that the study area has high groundwater recharge volume which could be used for different groundwater development projects. This study provides evidence for the groundwater potential areas identified by using geospatial methods and groundwater development projects that can be practiced in the area.

Keywords

• Baseflow separation
• Ethiopia
• Groundwater recharge
• Rib and gumara rivers