Analysis of the Hydrogeological and Hydrochemical Characteristics of an Immature Karst Aquifer System

This study intends, using classic and new techniques (e.g., Time Series Analysis, TSA), and hydrogeological data for the period February 2008 - May 2011, to improve the existing knowledge on the hydrogeology of the immature karst Philippi aquifer system (PHAS), Northeast Greece, in order to introduce the sustainable integrated water management of this system. The PHAS catchment consists of Mesozoic fissured and slightly karstified marbles, and covers an area of 121.7 km2. It discharges through the perennial, fault-controlled, overflow Voirani spring, which serves the needs of 85,000 inhabitants. Source of recharge is direct diffuse infiltration of precipitation. The Voirani spring mean discharge rate is 1.48 m3/s and ranges from 1 to 2.1 m3/s. Its variability index ranges from 1.73 to 2.07 m3/s. Auto- and cross-correlation and spectral analyses were used in combination with PHAS hydrogeological characteristics to study the interrelationship of daily spring discharge and rainfall, and provided useful information about the PHAS memory effect. PHAS baseflow prevailed greatly and had a behavior similar to a porous aquifer. The catchment area recharges and stores deep circulating water, while its karstification is poorly developed with high storages. The Voirani spring water is of Ca-HCO3 chemical type, of high quality, and oversaturated with respect to calcite. Examination of hydrograph and chemograph data revealed that PHAS is dominated by diffuse flow of stable hydrochemical composition. The application of TSA combined with classic hydrogeological techniques can be used in order to achieve a sustainable integrated water management of this system. © 2017, Springer International Publishing AG.