Understanding the origin of flood water in a urban karst spring using a high-frequency physico-chemical monitoring
Résumé
Through the analysis of high frequency physico-chemical time series at the Fontaine de Nîmes spring (South of France), we aim to improve our understanding of the hydrogeological responses and water origins in an urban karst catchment. Based on the study of 28 major flood events we shed light on relationships between solutes (electrical conductivity), particles (turbidity), or wastewater leaching from urban areas (natural fluorescence). We find that a seasonal flood typology helps explain the observed physico-chemical variability. Overall, this paper highlights the benefit of a multi-parameter monitoring at high resolution in order to better characterize water origin, depending on the seasonality for Mediterranean karst urban systems.