5 results on '"Cerdan, Olivier"'
Search Results
2. Investigating the temporal dynamics of suspended sediment during flood events with 7Be and 210Pbxs measurements in a drained lowland catchment
- Author
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Le Gall, Marion, Evrard, O., Foucher, Anthony, Laceby, J. Patrick, Salvador-Blanes, Sébastien, Manière, Louis, Lefevre, Irène, Cerdan, Olivier, Ayrault, Sophie, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Géochimie Des Impacts (GEDI), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), GéoHydrosystèmes COntinentaux (GéHCO EA6293), Université de Tours (UT), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), This work received financial support from the Loire-Brittany Water Agency (in the framework of the Tracksed and Drastic research projects)., AELB, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), and Université de Tours
- Subjects
GéoHydrosystèmes Continentaux (GéHCO) ,[SDU.STU]Sciences of the Universe [physics]/Earth Sciences ,[SDV.SA.SDS]Life Sciences [q-bio]/Agricultural sciences/Soil study ,Gif-sur-Yvette (France) 2 EA 6293 ,Panoply ,Article ,Tours (France) 3 Département Risques et Prévention ,Faculté des Sciences et Techniques ,Bureau de Recherches Géologiques et Minières ,[SDE]Environmental Sciences ,du CNRS ,[SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology ,[SDU.STU.HY]Sciences of the Universe [physics]/Earth Sciences/Hydrology ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment ,Université F Rabelais de Tours ,Orléans (France) - Abstract
International audience; Soil erosion is recognized as one of the main processes of land degradation in agricultural areas. High suspended sediment loads, often generated from eroding agricultural landscapes, are known to degrade downstream environments. Accordingly, there is a need to understand soil erosion dynamics during flood events. Suspended sediment was therefore sampled in the river network and at tile drain outlets during five flood events in a lowland drained catchment in France. Source and sediment fallout radionuclide concentrations (Be-7, Pb-210(xs)) were measured to quantify both the fraction of recently eroded particles transported during flood events and their residence time. Results indicate that the mean fraction of recently eroded sediment, estimated for the entire Louroux catchment, increased from 45 +/- 20% to 80 +/- 20% between December 2013 and February 2014, and from 65 +/- 20% to 80 +/- 20% in January 2016. These results demonstrate an initial flush of sediment previously accumulated in the river channel before the increasing supply of sediment recently eroded from the hillslopes during subsequent events. This research highlights the utility of coupling continuous river monitoring and fallout radionuclide measurements to increase our understanding of sediment dynamics and improve the management of soil and water resources in agricultural catchments.
- Published
- 2017
3. Renewed soil erosion and remobilisation of radioactive sediment in Fukushima coastal rivers after the 2013 typhoons.
- Author
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Evrard, Olivier, Chartin, Caroline, Yuichi Onda, Lepage, Hugo, Cerdan, Olivier, Lefèvre, Irène, and Ayrault, Sophie
- Subjects
SOIL erosion ,RADIOACTIVE pollution ,TYPHOONS ,FUKUSHIMA Nuclear Accident, Fukushima, Japan, 2011 ,COASTAL plains ,DECONTAMINATION (From gases, chemicals, etc.) ,RIVERS - Abstract
Summer typhoons and spring snowmelt led to the riverine spread of continental Fukushima fallout to the coastal plains of Northeastern Japan and the Pacific Ocean. Four fieldwork campaigns based on measurement of radioactive dose rates in fine riverine sediment that has recently deposited on channel bed-sand were conducted between November 2011 and May 2013 to document the spread of fallout by rivers. After a progressive decrease in the fresh riverine sediment doses rates between 2011 and early spring in 2013, a fifth campaign conducted in November 2013 showed that they started to increase again after the occurrence of violent typhoons. We show that this increase in dose rates was mostly due to remobilization of contaminated material that was temporarily stored in river channels or, more importantly, in dam reservoirs of the region during the typhoons. In addition, supply of particles from freshly eroded soils in autumn 2013 was the most important in areas where decontamination works are under progress. Our results underline the need to monitor the impact of decontamination works and dam releases in the region, as they may provide a continuous source of radioactive contamination to the coastal plains and the Pacific Ocean during the coming years. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
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4. Investigating the temporal dynamics of suspended sediment during flood events with 7Be and 210Pbxs measurements in a drained lowland catchment.
- Author
-
Le Gall, Marion, Evrard, Olivier, Foucher, Anthony, Laceby, J. Patrick, Salvador-Blanes, Sébastien, Manière, Louis, Lefèvre, Irène, Cerdan, Olivier, and Ayrault, Sophie
- Abstract
Soil erosion is recognized as one of the main processes of land degradation in agricultural areas. High suspended sediment loads, often generated from eroding agricultural landscapes, are known to degrade downstream environments. Accordingly, there is a need to understand soil erosion dynamics during flood events. Suspended sediment was therefore sampled in the river network and at tile drain outlets during five flood events in a lowland drained catchment in France. Source and sediment fallout radionuclide concentrations (
7 Be,210 Pbxs ) were measured to quantify both the fraction of recently eroded particles transported during flood events and their residence time. Results indicate that the mean fraction of recently eroded sediment, estimated for the entire Louroux catchment, increased from 45 ± 20% to 80 ± 20% between December 2013 and February 2014, and from 65 ± 20% to 80 ± 20% in January 2016. These results demonstrate an initial flush of sediment previously accumulated in the river channel before the increasing supply of sediment recently eroded from the hillslopes during subsequent events. This research highlights the utility of coupling continuous river monitoring and fallout radionuclide measurements to increase our understanding of sediment dynamics and improve the management of soil and water resources in agricultural catchments. [ABSTRACT FROM AUTHOR]- Published
- 2017
- Full Text
- View/download PDF
5. Investigating the temporal dynamics of suspended sediment during flood events with 7 Be and 210 Pb xs measurements in a drained lowland catchment.
- Author
-
Le Gall M, Evrard O, Foucher A, Laceby JP, Salvador-Blanes S, Manière L, Lefèvre I, Cerdan O, and Ayrault S
- Abstract
Soil erosion is recognized as one of the main processes of land degradation in agricultural areas. High suspended sediment loads, often generated from eroding agricultural landscapes, are known to degrade downstream environments. Accordingly, there is a need to understand soil erosion dynamics during flood events. Suspended sediment was therefore sampled in the river network and at tile drain outlets during five flood events in a lowland drained catchment in France. Source and sediment fallout radionuclide concentrations (
7 Be,210 Pbxs ) were measured to quantify both the fraction of recently eroded particles transported during flood events and their residence time. Results indicate that the mean fraction of recently eroded sediment, estimated for the entire Louroux catchment, increased from 45 ± 20% to 80 ± 20% between December 2013 and February 2014, and from 65 ± 20% to 80 ± 20% in January 2016. These results demonstrate an initial flush of sediment previously accumulated in the river channel before the increasing supply of sediment recently eroded from the hillslopes during subsequent events. This research highlights the utility of coupling continuous river monitoring and fallout radionuclide measurements to increase our understanding of sediment dynamics and improve the management of soil and water resources in agricultural catchments., Competing Interests: The authors declare no competing financial interests.- Published
- 2017
- Full Text
- View/download PDF
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