Author(s): Alan P. Mamani-Ramos, Roberto Alfaro

Linked Author(s): Roberto Alfaro-Alejo

Keywords: Base flow; Groundwater balance; Recharge; Groundwater;

Abstract: The present research work was carried out to estimate the base flow of the Chumpe River by means of surface and underground water balance. The study area is located in the province of Yauli, department of Junin, Peru, Latitude 11 ° 41.802'S, Longitude 76 ° 4.280'W and 4520 m. The water balance was calculated by adding the inputs and outputs in the sub-basin (precipitation, evapotranspiration, recharge, surface runoff and storage change), and evapotranspiration was calculated using the Thornthwaite method. The underground water balance was determined by numerical modeling of underground flow with the Modflow Software. The recharge assigned to the numerical model was determined by the method of fluctuation of piezometric levels observed (Water Table Fluctuation "WTF") in the piezometers quarterly during the hydrological year (2013 - 2014). The hydrogeological parameters of the aquitard (hydraulic conductivity and storage coefficient) were determined by means of permeability tests using the Lefranc and Lugueon methods performed during the drilling of 33 hydrogeological piezometers. The base flow calculated by means of surface and underground water balance was validated with the calculated recharge and also compared with flow rates observed and calculated by Lutz Scholz deterministic rainfall-runoff model. The base flow of the Chumpe River was determined between 20 and 40 l.s-1, equivalent to 6 to 12% of the annual rainfall, evaluated for the hydrological year (2013 - 2014).

DOI: https://doi.org/10.3850/38WC092019-0874

Year: 2019