Modeling the response of a karstic spring at Arteta aquifer in Spain

A linear response model based on daily spring discharges has been applied in simulating the response of the karstic aquifer feeding the Arteta spring in Navarra (Spain), which is used for the water supply of the city of Pamptona. The model is derived from the eigenvalue solution of the ground-water flow partial differential equation, a method that provides a continuously in time solution of this equation for finite-difference or finite-element space discretization. The modeling approach explains the recession curves composed by several decreasing exponentials observed in many karstic aquifers and differs from the classic assumption where the recession coefficients of these exponentials are identified with different flow regimes in conduit zones. Recharge-discharge transfer has been simulated using a limited number of parameters without having to resort to methods where the impulse-response function of the system is obtained by deconvolution.