Local-scale Solute Transport In Variously Structured Soils Under Continuous Flood Irrigation
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A. Comegna, A. Coppola, A. Sommella & G. Severino
This paper reports the results of research carried out to establish the possibility of using Time Domain Reflectometry (TDR) technology in measuring breakthrough curves of anion tracers such as chloride and bromide. The test conditions adopted refer to the case of undisturbed porous media with bimodal porosity under saturated-unsaturated conditions and to a liquid phase of assigned chemical characteristics. The BTCs were measured with vertically installed TDR probes. Interpretation of signal impedance was carried out in a similar fashion to Kachanosky et al. so as to obtain estimates of the minimum impedance load Z0. The measured BTCs were interpreted to estimate transport parameters by using a two-parameter convective-dispersive model. Finally, a sensitivity analysis of the hydrodynamic dispersion parameter as related both to the average pore water velocity v, and TDR measurement errors were performed. Keywords: solute transport models, chloride breakthrough curve, TDR calibration. 1 Introduction Contamination of groundwater has received considerable attention in recent years because of concerns about degradation of this important source of fresh water, with possible toxicological consequences. Contamination has often been associated with point sources such as disposal sites or illegal dumping of chemical and industrial wastes. More recently, non-point pollution has become the center of increased attention by the research community, both in urban and
solute transport models, chloride breakthrough curve, TDR calibration.