Seasonal and event-based concentration-discharge relationships to identify catchment controls on nutrient export regimes

Autor: Pierre-Alain Danis, Vincent Roubeix, Chantal Gascuel-Odoux, Rémi Dupas, Florentina Moatar, Camille Minaudo
Přispěvatelé: Physics of Aquatic Systems Laboratory [Lausanne], Ecole Polytechnique Fédérale de Lausanne (EPFL), GéoHydrosystèmes COntinentaux (GéHCO EA6293), Université de Tours, Sol Agro et hydrosystème Spatialisation (SAS), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Risques, Ecosystèmes, Vulnérabilité, Environnement, Résilience (RECOVER), Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Pôle d'Etudes et Recherches AFB-Irstea Hydroécologie des Plans d'eau (France), Agence Française pour la Biodiversité - AFB (FRANCE), RiverLy (UR Riverly), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Université de Tours (UT), Agence Française pour la Biodiversité (AFB), AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de la Recherche Agronomique (INRA), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Aix Marseille Université (AMU)
Rok vydání: 2019
Předmět:
Zdroj: Advances in Water Resources
Advances in Water Resources, Elsevier, 2019, 131, pp.103379. ⟨10.1016/j.advwatres.2019.103379⟩
Advances in Water Resources, 2019, 131, pp.103379. ⟨10.1016/j.advwatres.2019.103379⟩
ISSN: 0309-1708
DOI: 10.1016/j.advwatres.2019.103379
Popis: [Departement_IRSTEA]Eaux [ADD1_IRSTEA]Hydrosystèmes et risques naturels [ADD2_IRSTEA]Dynamique et fonctionnement des écosystèmes [ADD2_IRSTEA]Systèmes aquatiques soumis à des pressions multiples; International audience; The analysis of concentration-discharge (C-Q) relationships provides useful information on the processes controlling the mobilization and delivery of chemical elements into streams as well as biogeochemical transformations in river networks. Previous metrics developed to characterize export regimes seldom considered the possibility for the C response to Q dynamics to differ between short-term Q variations during storm events and seasonal Q variations during baseflow periods. Here, we present the “C-Qquick-slow” model, which considers the possibility for C-Q relationships to vary across temporal scales. This model was applied in 219 French catchments with various sizes (11–2500 km2), land use and hydrological contexts. We evidenced contrasting export regimes for nitrate (NO3 −), total phosphorus (TP) and soluble reactive phosphorus (SRP), and surprisingly consistent C-Q patterns at the seasonal scale for each parameter. For instance, NO3 −-Q relationships were positive at the seasonal scale in 75% cases and relationships during storms showed either a dilution pattern (24% cases), a non-significant pattern (50%), or a mobilization pattern (12%). TP and SRP relationships with Q at the seasonal scale were almostsystematically negative (95%), and patterns during storm events were in most cases mobilization for TP (77%) or non-significant for SRP (69%). We linked the different C-Q relationships with catchment descriptors and found that indicators of diffuse source loading determined NO3 − seasonal amplitudes, and hydrological drivers could explain the behavior during storms. By contrast, point sources determined P seasonal amplitudes, and diffuse sources controlled P dynamics during storms. The C-Qquick-slow model has the potential to improve nutrient loadestimations because of the good predictability of appropriate C-Q archetypes and the possibility to interpolate low frequency concentration data to a daily frequency
Databáze: OpenAIRE
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