A series of springs located in southern Piedmont (Northern Italy) fed by carbonate aquifers with extremely different hydrogeological characteristics, have been monitored continuously for their flowrate, temperature and electric conductivity. The acquired data have been confronted in order to evidence the different hydrodynamic and hydrochemical responses of these aquifers to infiltration inputs. The spring hydrographs can be distinguished in three different types: • Replacement, characterised by very fast increases in flowrate and a lowering of mineralisation values; this behavior is typical of highly karstified aquifers without a traditional phreatic zone (dominant conduit system); • Piston flow, with fast variations of flowrate accompanied by both mineralisation and temperature increases, evidencing the arrival at the spring of waters that resided in the phreatic zone of a quite well developed karstic aquifer. In this situation evident decreases in electric conductivity related to the arrival of freshly infiltrated water are not registered (interconnected conduit system); • Homogenization, characterised by very subdued and delayed increases in flowrate, accompanied by moderate variations of geochemical parameters, typical of a fractured aquifer (dispersed circulation system).
Study of springs and karst aquifers by monitoring and geochemical analysis
DE WAELE, JO HILAIRE AGNES;
2011
Abstract
A series of springs located in southern Piedmont (Northern Italy) fed by carbonate aquifers with extremely different hydrogeological characteristics, have been monitored continuously for their flowrate, temperature and electric conductivity. The acquired data have been confronted in order to evidence the different hydrodynamic and hydrochemical responses of these aquifers to infiltration inputs. The spring hydrographs can be distinguished in three different types: • Replacement, characterised by very fast increases in flowrate and a lowering of mineralisation values; this behavior is typical of highly karstified aquifers without a traditional phreatic zone (dominant conduit system); • Piston flow, with fast variations of flowrate accompanied by both mineralisation and temperature increases, evidencing the arrival at the spring of waters that resided in the phreatic zone of a quite well developed karstic aquifer. In this situation evident decreases in electric conductivity related to the arrival of freshly infiltrated water are not registered (interconnected conduit system); • Homogenization, characterised by very subdued and delayed increases in flowrate, accompanied by moderate variations of geochemical parameters, typical of a fractured aquifer (dispersed circulation system).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.