LASIR CNRS UMR 8516, University of Lille, 59 655 Villeneuve d'Ascq Cedex, France.
Artois-Picardy Water Agency, 200 rue Marceline, 59 500 Douai, France.
Sci Total Environ. 2019 Feb 20;652:289-299. doi: 10.1016/j.scitotenv.2018.10.246. Epub 2018 Oct 18.
The aim of this paper is to better understand the functioning of the River Selle (northern France) during dry weather and storm events, to assess the impact of a town on the surface water quality and to suggest qualitative assumptions on the vulnerability of water quality to weather conditions. Two high-frequency monitoring stations covering the Cateau-Cambrésis town were deployed during 4 months in 2016. River flow, water temperature, pH, dissolved oxygen, turbidity, conductivity, total organic carbon, nitrates and phosphates were monitored every 10 min. The water supply of the River Selle is mainly dominated by groundwater as shown by the behaviour of the river flow, the water temperature and the nitrate concentrations in both surface water and groundwater. The reference station located at the upstream of the river (Saint Souplet) exhibits low anthropogenic pressure during dry weather but is significantly impacted during storm events. At the downstream of the Cateau-Cambrésis town, the water quality is severely impacted by phosphates during dry weather mainly due to wastewater inputs into the river. An additional load of pollution is highlighted during storm events. According to our results, the water quality of the River Selle would degrade if actions to reduce dry-weather and storm events pollution sources are not undertaken rapidly. Moreover, nutrients, particularly phosphates, are clearly in excess in this system. Efforts to combat soil leaching and the revision of sewage systems and urban wastewater treatment in the catchment are two key points to tackle. Finally, this study shows the importance of understanding the current behaviour of a given river towards dry weather and storm events before suggesting local scenarios of the impact of climate change on surface water quality.
本文旨在更好地了解法国北部塞勒河在干旱天气和风暴事件期间的运行情况，评估城镇对地表水水质的影响，并对水质对天气条件的脆弱性提出定性假设。在 2016 年的 4 个月中，在卡托-康布雷兹镇部署了两个高频监测站。在 2016 年的 4 个月中，在卡托-康布雷兹镇部署了两个高频监测站，每 10 分钟监测一次流量、水温、pH 值、溶解氧、浊度、电导率、总有机碳、硝酸盐和磷酸盐。河水流量、水温和地表水和地下水中的硝酸盐浓度表明，河水的补给主要来自地下水。位于河流上游的参考站（圣苏普莱）在干旱天气下表现出较低的人为压力，但在风暴事件中受到显著影响。在卡托-康布雷兹镇的下游，由于污水排入河流，干旱天气期间磷酸盐严重影响水质。在风暴事件期间，还突出了额外的污染负荷。根据我们的结果，如果不迅速采取行动减少干旱天气和风暴事件污染源，塞勒河的水质将恶化。此外，该系统中磷等营养物明显过剩。减少集水区土壤淋溶的努力以及污水系统和城市污水处理的修订是需要解决的两个关键点。最后，本研究表明，在提出气候变化对地表水质量影响的当地情景之前，了解给定河流在干旱天气和风暴事件下当前行为的重要性。
