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Bertrand G, Ponçot A, Pohl B, Lhosmot A, Steinmann M, Johannet A, Pinel S, Caldirak H, Artigue G, Binet P, Bertrand C, Collin L, Magnon G, Gilbert D, Laggoun-Deffarge F, Toussaint ML. Statistical hydrology for evaluating peatland water table sensitivity to simple environmental variables and climate changes application to the mid-latitude/altitude Frasne peatland (Jura Mountains, France). Sci Total Environ 2021; 754:141931. [PMID: 33254862 DOI: 10.1016/j.scitotenv.2020.141931] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 07/30/2020] [Accepted: 08/22/2020] [Indexed: 06/12/2023]
Abstract
Peatlands are habitats for a range of fragile flora and fauna species. Their eco-physicochemical characteristics make them as outstanding global carbon and water storage systems. These ecosystems occupy 3% of the worldwide emerged land surface but represent 30% of the global organic soil carbon and 10% of the global fresh water volumes. In such systems, carbon speciation depends to a large extent on specific redox conditions which are mainly governed by the depth of the water table. Hence, understanding their hydrological variability, that conditions both their ecological and biogeochemical functions, is crucial for their management, especially when anticipating their future evolution under climate change. This study illustrates how long-term monitoring of basic hydro-meteorological parameters combined with statistical modeling can be used as a tool to evaluate i) the horizontal (type of peat), ii) vertical (acrotelm/catotelm continuum) and iii) future hydrological variability. Using cross-correlations between meteorological data (precipitation, potential evapotranspiration) and water table depth (WTD), we primarily highlight the spatial heterogeneity of hydrological reactivity across the Sphagnum-dominated Frasne peatland (French Jura Mountain). Then, a multiple linear regression model allows performing hydrological projections until 2100, according to regionalized IPCC RCP4.5 and 8.5 scenarios. Although WTD remains stable during the first half of 21th century, seasonal trends beyond 2050 show lower WTD in winter and markedly greater WTD in summer. In particular, after 2050, more frequent droughts in summer and autumn should occur, increasing WTD. These projections are completed with risk evaluations for peatland droughts until 2100 that appear to be increasing especially for transition seasons, i.e. May-June and September-October. Comparing these trends with previous evaluations of phenol concentrations in water throughout the vegetative period, considered as a proxy of plant functioning intensity, highlights that these hydrological modifications during transitional seasons could be a great ecological perturbation, especially by affecting Sphagnum metabolism.
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Affiliation(s)
- Guillaume Bertrand
- University of Bourgogne Franche-Comté, UMR UFC CNRS 6249 Chrono-Environnement, 1- route de Gray 25000 Besançon, 4 place Tharradin, 25200 Montbéliard, France.
| | - Alex Ponçot
- University of Bourgogne Franche-Comté, UMR UFC CNRS 6249 Chrono-Environnement, 1- route de Gray 25000 Besançon, 4 place Tharradin, 25200 Montbéliard, France.
| | - Benjamin Pohl
- Biogéosciences, UMR6282 CNRS, University of Bourgogne Franche-Comté, 6 boulevard Gabriel, F-21000 Dijon, France
| | - Alexandre Lhosmot
- University of Bourgogne Franche-Comté, UMR UFC CNRS 6249 Chrono-Environnement, 1- route de Gray 25000 Besançon, 4 place Tharradin, 25200 Montbéliard, France
| | - Marc Steinmann
- University of Bourgogne Franche-Comté, UMR UFC CNRS 6249 Chrono-Environnement, 1- route de Gray 25000 Besançon, 4 place Tharradin, 25200 Montbéliard, France
| | - Anne Johannet
- IMT Mines Ales, 8, rue Jules Renard, 30319 Alès cedex, France
| | - Sébastien Pinel
- IMT Mines Ales, 8, rue Jules Renard, 30319 Alès cedex, France
| | | | | | - Philippe Binet
- University of Bourgogne Franche-Comté, UMR UFC CNRS 6249 Chrono-Environnement, 1- route de Gray 25000 Besançon, 4 place Tharradin, 25200 Montbéliard, France
| | - Catherine Bertrand
- University of Bourgogne Franche-Comté, UMR UFC CNRS 6249 Chrono-Environnement, 1- route de Gray 25000 Besançon, 4 place Tharradin, 25200 Montbéliard, France
| | - Louis Collin
- EPAGE Syndicat Mixte Haut-Doubs Haute-Loue, 3 rue de la gare, 25560 Frasne, France
| | - Geneviève Magnon
- EPAGE Syndicat Mixte Haut-Doubs Haute-Loue, 3 rue de la gare, 25560 Frasne, France
| | - Daniel Gilbert
- University of Bourgogne Franche-Comté, UMR UFC CNRS 6249 Chrono-Environnement, 1- route de Gray 25000 Besançon, 4 place Tharradin, 25200 Montbéliard, France
| | | | - Marie-Laure Toussaint
- University of Bourgogne Franche-Comté, UMR UFC CNRS 6249 Chrono-Environnement, 1- route de Gray 25000 Besançon, 4 place Tharradin, 25200 Montbéliard, France
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Marmonier P, Creuzé des Châtelliers M, Dole-Olivier MJ, Radakovitch O, Mayer A, Chapuis H, Graillot D, Re-Bahuaud J, Johannet A, Cadilhac L. Are surface water characteristics efficient to locate hyporheic biodiversity hotspots? Sci Total Environ 2020; 738:139930. [PMID: 32531611 DOI: 10.1016/j.scitotenv.2020.139930] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/01/2020] [Accepted: 06/01/2020] [Indexed: 06/11/2023]
Abstract
Location of river-groundwater exchange zones and biodiversity hotspot is essential for a river management plan, especially for Mediterranean karstic rivers. This location is often difficult and time-consuming when long river sectors are considered. We studied a 13 km-long sector of the Cèze River (Southern France) located in a karstic canyon. We compared five indicators of river-groundwater exchanges: longitudinal profiles of temperature, electrical conductivity and 222Rn concentrations in the surface water of the river, chemical characteristics of the hyporheic water and hyporheic biodiversity. Upwelling zones occurred downstream of geomorphological heterogeneities (here at the tail of gravel bars). Surface water chemistry, especially electrical conductivity and 222Rn concentrations, clearly traces large scale gaining sections, which were not associated to valley narrowing but with lateral springs, suggesting a crucial role of the geological structuration of the karstic plateau of Méjanne-le-Clap. Hyporheic water chemistry fits with the large-scale hydrological pattern, but with a high variability corresponding to local heterogeneities. The stygobite fauna (obligate groundwater organisms) and benthic EPTC (Ephemeroptera, Plecoptera, Trichoptera and Coleoptera) occurred preferentially in the gaining sections fed by groundwater, likely because of oligotrophic water and cooler temperature. The spatial distribution of river-groundwater exchange zone and hyporheic biodiversity may be thus predicted using changes in surface water chemistry, especially for electrical conductivity and 222Rn concentrations.
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Affiliation(s)
- P Marmonier
- Univ. Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNA, 43 boulevard du 11 Novembre 1918, 69622 Villeurbanne, France.
| | - M Creuzé des Châtelliers
- Univ. Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNA, 43 boulevard du 11 Novembre 1918, 69622 Villeurbanne, France
| | - M J Dole-Olivier
- Univ. Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNA, 43 boulevard du 11 Novembre 1918, 69622 Villeurbanne, France
| | - O Radakovitch
- Aix Marseille Univ, CNRS, IRD, INRA, Coll France, CEREGE, Aix-en-Provence, France; Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-SRTE-LRTA, CADARACHE, France
| | - A Mayer
- Université d'Avignon - EMMAH, UFR-ip Sciences, Technologies, Santé - Campus Jean-Henri Fabre, 301 rue Baruch de Spinoza, BP 21239, 84916 AVIGNON Cedex 9, France
| | - H Chapuis
- École Nationale des Mines de Saint-Étienne, UMR-CNRS 5600 EVS, 158 cours Fauriel, 42023 Saint-Étienne, France
| | - D Graillot
- École Nationale des Mines de Saint-Étienne, UMR-CNRS 5600 EVS, 158 cours Fauriel, 42023 Saint-Étienne, France
| | - J Re-Bahuaud
- IMT Mines Alès, Université de Montpellier, 6 avenue de Clavières, 30319 Alès, France
| | - A Johannet
- IMT Mines Alès, Université de Montpellier, 6 avenue de Clavières, 30319 Alès, France
| | - L Cadilhac
- Agence de l'Eau Rhône Méditerranée et Corse, 2 allée de Lodz, 69007 Lyon, France
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Johannet A, Personnaz L, Dreyfus G, Gascuel JD, Weinfeld M. Specification and implementation of a digital Hopfield-type associative memory with on-chip training. IEEE Trans Neural Netw 1992; 3:529-39. [PMID: 18276455 DOI: 10.1109/72.143369] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The definition of the requirements for the design of a neural network associative memory, with on-chip training, in standard digital CMOS technology is addressed. Various learning rules that can be integrated in silicon and the associative memory properties of the resulting networks are investigated. The relationships between the architecture of the circuit and the learning rule are studied in order to minimize the extra circuitry required for the implementation of training. A 64-neuron associative memory with on-chip training has been manufactured, and its future extensions are outlined. Beyond the application to the specific circuit described, the general methodology for determining the accuracy requirements can be applied to other circuits and to other autoassociative memory architectures.
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Affiliation(s)
- A Johannet
- Lab. d'Electron., Ecole Superieure de Phys. et de Chimie Ind. de la Ville de Paris
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