title: CCD camera image analysis for mapping solute concentrations in saturated porous media.
abstract: This paper presents an optical approach, based on the use of a low-cost charge-coupled device (CCD) camera, for the quantitative determination of solute concentrations in saturated porous media. The method is applied to evaluate tracer experiments carried out in a laboratory model tank. The CCD photos deliver RGB values which are transferred into concentrations for the evaluation of vertical concentration profiles over the whole tank area. A specially developed evaluation procedure, including internal referencing for noise reduction, considers the colour of the adjacencies of the evaluated spots and scattering effects. The CCD data evaluation technique is accompanied by conventional sampling and absorption measurements and by numerical flow and transport simulations. This non-invasive technique allows a direct mapping of the concentration distribution without any disturbance of the solute plume. Therefore, it turns out to be an important tool for a detailed investigation of fundamental processes (e.g. transverse dispersion) determining the solute (e.g. contaminant) transport in porous media.
authors: Institute of Physical and Theoretical Chemistry, University of Tuebingen, Auf der Morgenstelle 18, 72076, Tuebingen, Germany. stefanie.jaeger@ipc.uni-tuebingen.de
authors: Stefanie
authors: S
authors: Jaeger
authors: Markus
authors: M
authors: Ehni
authors: Christina
authors: C
authors: Eberhardt
authors: Massimo
authors: M
authors: Rolle
authors: Peter
authors: P
authors: Grathwohl
authors: Guenter
authors: G
authors: Gauglitz