Main hydrological features and recharge analysis of the caposele spring catchment, southern Italy

Francesco Fiorillo, Libera Esposito, Mauro Pagnozzi, Zoran Stevanović & Gerardo Ventafridda: Main hydrological features and recharge analysis of the Caposele Spring catchment, southern Italy The Caposele spring supplies with water the Puglia region (southern Italy) since the beginning of the twentieth century by a wide and long (about 400 km) gravity-aqueduct system. Systematic spring discharge measurements exist since 1920. The annual mean discharge of spring is about 4 m 3 /sec, the spring catchment of the of Mt. Cervialto karst massif is estimated on more than 100 km 2 . The spring regime is characterised by absence of abrupt peaks in the hydrographs; the flood period occurs in spring-summer time, and the minimum during the autumn-winter time. Thus, the regime is almost opposite that of rainfall which allows a convenient management of the source. The historical data have shown that spring discharge depends also on the hydrological conditions of the previous year because the ‘‘memory effect” of aquifer. The recharge processes have been evaluated using a daily scale recharge model, calibrated on long term annual scale. The results allow to estimate the inertial behaviour of the aquifer, by the difference of recharged and discharged water volume during a hydrological year: after a wet year, an amount of water volume is retained into the aquifer and constitutes the surplus volume stored; after a dry year, the aquifer discharges a water volume higher than the recharged volume (a deficit in storage).