Quantification des flux et des stocks solides holocènes dans le bassin de la Loire (France)

Quantification of Holocene sediment flux and stocks in the Loire catchment (France)

UPRES EA 2100, Laboratoire de Géologie des Environnements Aquatiques Continentaux, GéEAC, Université de Tours Faculté des Sciences et Techniques, Parc de Grandmont, 37200 Tours

Auteur de correspondance : macaire@univ-tours.fr

Abstract

Quantity of solid matter yielded and stored during the Holocene period in the whole Loire catchment was calculated from two little catchments located in the Massif Central and in the Parisian Basin. The Massif Central produced tenfold more solid matter than the Parisian Basin (56.10⁹ t versus 5,5.10⁹ t) and fourfold less dissolved matter (6,9.10⁹ t versus 28,2.10⁹ t). Solid matter yielded by the Massif Central was evacuated downward to the main rivers where it was mainly stored. Solid matter yielded by the Parisian Basin was mainly stored in the small catchments and a small part only reached the main rivers. Anthropic increase of sediment yield during the last 1000 years quickly increased sediment flux in the river of the Massif Central while it appears to be differed, because solid matter was stored as colluvium on slopes, in the Parisian Basin.