Search results for "polluants organiques"
showing 2 items of 2 documents
Démarche statistique pour la sélection des indicateurs par Random Forests pour la surveillance de la qualité des sols
2013
The volume of data, and the large number of biological variables to be tested (one hundred), require analytical techniques, such asRandom Forests, which can overcome the problem of multi-colinearity for the selection of indicators, sensitive to various factors.Random Forests methodology is appropriate for the selection of the most discriminant variables. So, we searched for the best wayto select them, by bringing together all biological variables, representing the Microflora and Fauna. This approach focuses on impactindicators from the Bio2 program, indicators of flora and indicators of accumulation (snails) were not included.This work has been implemented on the three factors of discrimina…
Shared effects of organic microcontaminants and environmental stressors on biofilms and invertebrates in impaired rivers
2016
Land use type, physical and chemical stressors, and organic microcontaminants were investigated for their effects on the biological communities (biofilms and invertebrates) in several Mediterranean rivers. The diversity of invertebrates, and the scores of the first principal component of a PCA performed with the diatom communities were the best descriptors of the distribution patterns of the biological communities against the river stressors. These two metrics decreased according to the progressive site impairment (associated to higher area of agricultural and urban-industrial, high water conductivity, higher dissolved organic carbon and dissolved inorganic nitrogen concentrations, and high…