Suspended Sediment Transfer in Seine River Watershed, France: a Strategy Using Fingerprinting From Trace Elements.

Publication TypeConference Proceedings
Year of Conference2002
AuthorsTessier, L, Bonté, P
Conference NameScience for Water Policy: the implications of the Water Framework Directive
Date Published02/09/2002
Conference LocationNorwich
In recent years there has been increasing recognition of the need to include sediment control strategies within basin management plans. In some situations, information on the source of the sediments transported by rivers is difficult to obtain using traditional tracers (majors elements, metals, Sr ratio…). The global purpose of this study is to use complex elemental pattern approach to determine the nature and landscape origin of suspended sediments in surface waters of the Seine basin, France. In the present paper, we focused our attention on the natural signature of suspended sediments revealed by the behaviour of the lithophile elements. Therefore, Sc, Co, Rb, Fe, Cs, Th, Ta, and Rare Earth Element (REE) have been determined in suspended sediment samples using Instrumental Neutron Activation Analysis (INAA). In order to take into account spatial and temporal variability, (i) study area covers the whole Seine basin from the headwaters to estuarial ones and (ii) sampling was performed over a three year period beginning in 1999. The survey revealed three specific points. First, Sc, Fe, Co and Rb have similar behaviour on the whole basin and their abundance is a function of clay proportion in suspended sediments. Second, the Cs/Sc ratio provides a clear proxy to control the evolution of suspended sediment derived from the crystalline rocks.