David A., Tournoud M. G., Perrin Jean-Louis, Rosain D., Rodier C., Salles C., Bancon-Montigny C., Picot B. (2013). Spatial and temporal trends in water quality in a Mediterranean temporary river impacted by sewage effluents. Environmental Monitoring and Assessment, 185 (3), p. 2517-2534. ISSN 0167-6369.
Titre du document
Spatial and temporal trends in water quality in a Mediterranean temporary river impacted by sewage effluents
David A., Tournoud M. G., Perrin Jean-Louis, Rosain D., Rodier C., Salles C., Bancon-Montigny C., Picot B.
Source
Environmental Monitoring and Assessment, 2013,
185 (3), p. 2517-2534 ISSN 0167-6369
This paper analyzes how changes in hydrological conditions can affect the water quality of a temporary river that receives direct inputs of sewage effluents. Data from 12 spatial surveys of the VSne river were examined. Physico-chemical parameters, major ion, and nutrient concentrations were measured. Analyses of variance (ANOVA) and multivariate analyses were performed. ANOVA revealed significant spatial differences for conductivity and major ion but no significant spatial differences for nutrient concentrations even if higher average concentrations were observed at stations located downstream from sewage effluent discharge points. Significant temporal differences were observed among all the parameters. Karstic springs had a marked dilution effect on the direct disposal of sewage effluents. During high-flow periods, nutrient concentrations were high to moderate whereas nutrient concentrations ranged from moderate to bad at stations located downstream from the direct inputs of sewage effluents during low-flow periods. Principal component analysis showed that water quality parameters that explained the water quality of the VSne river were highly dependent on hydrological conditions. Cluster analysis showed that when the karstic springs were flowing, water quality was homogeneous all along the river, whereas when karstic springs were dry, water quality at the monitoring stations was more fragmented. These results underline the importance of considering hydrological conditions when monitoring the water quality of temporary rivers. In view of the pollution observed in the VSne river, "good water chemical status" can probably only be achieved by improving the management of sewage effluents during low-flow periods.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020]
;
Hydrologie [062]
