engleski

Laboratory determination of longitudinal dispersivity in Fluvisol

The subject of this research is longitudinal dispersivity in Fluvisol. The aim is to determine the parameters of flow (hydraulic conductivity) and transport of contaminants (longitudinal dispersivity) on the soil column in the laboratory. The longitudinal dispersivity experiment was conducted using a conservative tracer calcium chloride (CaCl2) on samples taken from two different soil horizons at the Kosnica site above Zagreb aquifer system. Based on the experiment, saturated hydraulic conductivity (Ks) and longitudinal dispersivity (λ) were inversely modeled using HYDRUS 1-D software. For the sample of silty loam soil taken from the AC-C horizon, the value obtained for the saturated hydraulic conductivity was 0.01 cm/min, while the value obtained for the longitudinal dispersivity was 1.02 cm. For the sample of sandy loam soil taken from 2C/C1 horizon, the value obtained for the saturated hydraulic conductivity was 0.04 cm/min, while the value obtained for the longitudinal dispersivity was 1.72 cm. The correlation coefficient of the measured and simulated values of tracer concentration is 0.41 and 0.74 for AC-C horizon and 2C/C1 horizon, respectively. It can be concluded that the values of longitudinal disperivity for soil samples taken from the site Kosnica are in the limits of normal values for these types of soil, and the simulation parameter is acceptable. The results of the laboratory experiment can be used as the basis for assessment of contamination risk for groundwater.

Fluvisol; longitudinal dispersivity; contaminant transport; modeling

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