Prediction of Flow in a Karstic Aquifer, Case Yumagual, Cajamarca, Peru

The study describes the variables to establish the conceptual hydrogeological model and define the hydrogeological units, the recharge zones, the discharge zones, the direction of flow, the piezometric behavior, among others. The hydrogeological numerical model was developed in steady state (natural conditions) and transitory regime. The error percentage in the modeling is 6%, which is considered acceptable when dealing with such heterogeneous media. The permeability data were obtained from the permeability and pumping tests carried out in the area, obtaining the following ranges: Agglomerates of Volcanic Tuffs of 5.00•10^-9 to 9.40•10^-6 m/s, Diorites of 2.40•10^-10 to 2.36•10^-6 m/s, fault breccia of 8.10•10^-10 to 2.02•10^-6 m/s, Limestones from 3.50•10^-10 to 1.02•10^-5 m/s, Dioritic porphyries from 1.60•10^-10 to 3.36•10^-5 m/s, Rhyolites from 3.40•10^-9 to 1.20•10^-6 m/s, Rhyolitic breccias of 5.00•10^-9 to 5.70•10^-7 m/s, Rhyolitic tuffs of 3.10•10^-9 to 1.76•10^-6 m/s, Sands and gravels of 2.61•10^{- 5} to 9.83•10^-5 m/s and Soils: 1.00•10^-6 m/s. With the numerical model in transitory regime, a simulation was carried out to establish the total drainage flow, which ensures that the water table is 10 m below the ground level, according to the mining plan of pit 01. The flow was estimated of drainage of the pit and the drainage of the pit was simulated under three scenarios based on the pumping flow rates of the existing pumping wells.