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The saturation aspects of a large aperture (0.3 m) scintillometer operating over a 10-km path were investigated. Measurements were made over mainly forested, hilly terrain with typical maximum sensible heat fluxes of 300-400 W m(-2), and over flat terrain with mainly grass, and typical maximum heat fluxes of 100-150 W m(-2). Scintillometer-based fluxes were compared with eddy-correlation observations. Two different schemes for calculating the reduction of scintillation caused by saturation were applied: one based on the work of Hill and Clifford, the other based on Frehlich and Ochs. Without saturation correction, the scintillation fluxes were lower than the eddy-correlation fluxes; the saturation correction according to Frehlich and Ochs increased the scintillometer fluxes to an unrealistic level. Correcting the fluxes after the theory of the Hill and Clifford gave satisfying results.

Denitrification is a complex process. In literature, this process is mostly described by a simplified process model. From a literature review, the consensus model describes the actual denitrification rate as being equal to some potential denitrification rate subsequently reduced by soil environmental conditions. Typically, potential denitrification is reduced by nitrate content, degree of saturation (water content) as a measure for anaerobic conditions, soil temperature, and possibly soil pH. There is, however, much less consensus about the actual shape of the reduction functions. This indicates that these reduction functions are site (soil) specific. From a sensitivity analysis it follows that this model is most sensitive to the water content reduction function. Available data sets were used to determine if these can be used to parameterize the reduction functions. It appears that this is rather difficult, since mostly the measured actual denitrification rate is much less than the potential denitrification rate. Therefore, the reduction functions need to be determined independently.

Denitrification is a complex process. In literature, this process is mostly described by a simplified process model. From a literature review, the consensus model describes the actual denitrification rate as being equal to some potential denitrification rate subsequently reduced by soil environmental conditions. Typically, potential denitrification is reduced by nitrate content, degree of saturation (water content) as a measure for anaerobic conditions, soil temperature, and possibly soil pH. There is, however, much less consensus about the actual shape of the reduction functions. This indicates that these reduction functions are site (soil) specific. From a sensitivity analysis it follows that this model is most sensitive to the water content reduction function. Available data sets were used to determine if these can be used to parameterize the reduction functions. It appears that this is rather difficult, since mostly the measured actual denitrification rate is much less than the potential denitrification rate. Therefore, the reduction functions need to be determined independently.