Modelling the inorganic nitrogen behaviour in a small Mediterranean forested catchment, Fuirosos (Catalonia)

The aim of this work was to couple a nitrogen (N) sub-model to already existent hydrological lumped (LU4-N) and semi-distributed (LU4-R-N and SD4-R-N) conceptual models, to improve our understanding of the factors and processes controlling nitrogen cycling and losses in Mediterranean catchments. The N model adopted provides a simplified conceptualization of the soil nitrogen cycle considering mineralization, nitrification, immobilization, denitrification, plant uptake, and ammonium adsorption/desorption. It also includes nitrification and denitrification in the shallow perched aquifer. We included a soil moisture threshold for all the considered soil biological processes. The results suggested that all the nitrogen processes were highly influenced by the rain episodes and that soil microbial processes occurred in pulses stimulated by soil moisture increasing after rain. Our simulation highlighted the riparian zone as a possible source of nitrate, especially after the summer drought period, but it can also act as an important sink of nitrate due to denitrification, in particular during the wettest period of the year. The riparian zone was a key element to simulate the catchment nitrate behaviour. The lumped LU4-N model (which does not include the riparian zone) could not be validated, while both the semi-distributed LU4-R-N and SD4-R-N model (which include the riparian zone) gave satisfactory results for the calibration process and acceptable results for the temporal validation process.

L'environnement auditif au travail

À haute intensité, les deux principales sources d'inconfort physique au travail sont la chaleur et le bruit (Pellerin & Candas, 2003). Même à des intensités modérées et faibles, le bruit affecte les performances cognitives, y compris dans les tâches de bureau courantes, mais il le fait de plusieurs manières différentes selon la nature du bruit (par exemple, discours vs. non-discours, intensité sonore, variabilité et prévisibilité etc.) et le type de tâche dans laquelle l'individu ou le groupe est engagé. Il est un peu surprenant, donc, que les individus expriment souvent une préférence pour travailler dans des conditions de bruit modérées (Schlittmeier & Hellbrück, 2009). Les multiples formes de perturbation auditive nuisant aux performances cognitives sont examinées et comparées avec leurs avantages potentiels dans le cadre du travail, résultant du traitement du bruit de fond en termes de sens du lieu, d'apprentissage fortuit des régularités dans le monde auditif, et de commutation intelligente de l'attention.