Geophysical Research Abstracts Vol. 12, EGU2010-2634-1, 2010 EGU General Assembly 2010 © Author(s) 2010 Inﬂuence of the heterogeneity on the hydraulic conductivity of a real aquifer Fallico Carmine, Ferrante Aldo Pedro, Vita Maria Chiara, and De Bartolo Samuele Department of Soil Conservation, University of Calabria, Rende, Italy (fallico@dds.unical.it/+39984494050) Abstract Many factors inﬂuence the ﬂux in the porous media therefore the values of the representative parameters of the aquifer such as the hydraulic conductivity (k). A lot of studies have shown that this parameter increases with the portion of the aquifer tested. The main cause of this behaviour is the heterogeneity in the aquifer (Sànchez-Vila et al., 1996). It was also veriﬁed that the scale dependence of hydraulic conductivity does not depend on the speciﬁc method of measurement (Schulze-Makuch and Cherkauer, 1998). An experimental approach to study this phenomenon is based on sets of measurements carried out at different scales. However, one should consider that for the lower scale values k can be determined by direct measurements, performed in the laboratory using samples of different dimensions; whyle, for the large scales the measurement of the hydraulic conductivity requires indirect methods (Johnson and Sen, 1988; Katz and Thompson, 1986; Bernabé and Revil, 1995). In this study the conﬁned aquifer of Montalto Uffugo test ﬁeld was examined. This aquifer has the geological characteristics of a recently formed valley, with conglomeratic and sandy alluvial deposits; speciﬁcally the layer of sands and conglomerates, with a signiﬁcant percentage of silt at various levels, lies about 55-60 m below the ground surface, where there is a heavy clay formation. Moreover in the test ﬁeld, for the considered conﬁned aquifer, there are one completely penetrating well, ﬁve partially penetrating wells and two completely penetrating piezometers. Along two vertical lines a series of cylindrical samples (6.4 cm of diameter and 15 cm of head) were extracted and for each one of them the k value was measured in laboratory by direct methods, based on the use of ﬂux cells. Also indirect methods were used; in fact, a series of slug tests was carried out, determining the corresponding k values and the radius of inﬂuence (R). Moreover another series of pumping tests was carried out determining again the corresponding k values and the radius of inﬂuence; in fact, changing the pumping rate, varies also R. For the different sets of k values, obtained by different measurement methods, a statistical analysis was performed, determining the meaningful statistical parameters. All the obtained k values were examined, furnishing a scaling law of k for the considered aquifer. The equation describing this experimental trend is a power law, according to Schulze-Makuch and Cherkauer (1998). These results, obtained for the Montalto Uffugo test ﬁeld, show that the hydraulic conductivity grows with the radius of inﬂuence, id est with the volume of the aquifer involved in the measurement. Moreover, the threshold value, to which k tends with the growing of R, was determined. References Bernabé, Y. and Revil, A. 1995. Pore-scale heterogeneity, energy dissipation and the transport properties of rocks. Geophys. Res. Lett. 22: 1529-1532. Johnson, D.L. and Sen, P.N. 1988. Dependence of the conductivity of a porous medium on electrolytic conductiv- ity. Phys. Rev. B Condens. matter. 37: 3502-3510. Katz, A.J. and Thompson, A.H. 1986. Quantitative prediction of permeability in porous rock. Phys. Rev. B Condens. Matter. 34: 8179-8181. Sanchez-Villa X, Carrera J, Girardi JP (1996). Scale effects in transmissivity. J Hydrol 183:1–22. Schulze-Makuch D, Cherkauer DS (1998). Variations in hydraulic conductivity with scale of measurement during aquifer tests in heterogeneous, porous, carbonate rocks. Hydrogeol J. 6:204–215.