MODELING THE RESPONSE OF A KARSTIC SPRING AT ARTETA AQUIFER IN SPAIN

A linear response model based on daily spring discharges has been appl ied in simulating the response of the karstic aquifer feeding the Arte ta spring in Navarra (Spain), which is used for the water supply of th e 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-d ifference or finite-element space discretization. The modeling approac h explains the recession curves composed by several decreasing exponen tials observed in many karstic aquifers and differs from the classic a ssumption where the recession coefficients of these exponentials are i dentified with different flow regimes in conduit zones. Recharge-disch arge transfer has been simulated using a limited number of parameters without having to resort to methods where the impulse-response functio n of the system is obtained by deconvolution.