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Jean-Luc PEIRY

Professeur à l’université Blaise Pascal, université Clermont Auvergne, actuellement en détachement au CNRS en tant que directeur de recherche (1er septembre 2016 au 31 août 2019) avec affectation à l’UMI « Environnement, Santé, Société » à Dakar, Sénégal.

Équipe
« Dynamiques géoenvironnementales actuelles »

Contact : j-luc.peiry@uca.fr
Tél (SN) : +221 78 458 60 46
Tél (F) : +33 625 97 64 93





Thématiques de recherche/Research topics

  • Hydrogéomorphologie fluviale
  • Evaluation des impacts dans les hydrosystèmes fluviaux anthropisés
  • Gestion et restauration des rivières

Terrains de recherche/Study areas

  • Sénégal
  • Rivières du Massif Central, rivière Allier
  • Rivières des Alpes du Nord

Programmes de recherche/Research programs

  • Contrat de Projet Etat/Région Auvergne, volet Environnement, action de recherche « Fonctionnement, dynamique et gestion des milieux aquatiques : Fonctionnement géomorphologique et écologique des paléochenaux et annexes hydrauliques de la rivière Allier : implications de gestion et restauration » (2008-13). Responsable de l’action J-L PEIRY.
  • Programme GALE&T « Eau et Territoires » (2008-12) du MEDDAT, de l’INEE-CNRS et du CEMAGREF. Responsable du programme J. STEIGER.

Direction de Thèses en cours ou soutenues/PhD supervision

  • MAYORAL PASCUAL, Alfredo : Analyse de sensibilité aux forçages anthropo-climatiques des paysages protohistoriques et antiques du plateau volcanique de Corent (Auvergne) et de ses marges par une approche géoarchéologique pluri-indicateurs. Codirection : Jean-Luc PEIRY (UBP) et Jean-François BERGER (CNRS, Lyon) (première inscription février 2014).
  • HORTOBÁGYI, Borbála : Réponses et effets de la végétation sur la dynamique fluviale : processus fondamentaux et gestion environnementale. Codirection : Jean-Luc PEIRY et Dov CORENBLIT (première inscription octobre 2013).
  • CASADO, A.-L. (2013) : Human impacts and fluvial metamorphosis : the effects of flow regulation on the hydrology, morphology and water temperature of the Sauce Grande River, Argentina. Thèse de Géographie en cotutelle franco-argentine de l’Université Blaise Pascal – Clermont-Ferrand 2 et de l’Universidad Nacional del Sur (Bahia Blanca, Argentina), 375 p. (codirecteur, 80%, soutenance le 18 juin 2013).
  • POIRAUD, A. (2012) : Les glissements de terrain dans le bassin tertiaire volcanisé du Puy en Velay (Massif central, France) : caractérisation, facteurs de contrôle et cartographie de l’aléa. Thèse de Géographie de l’Université Blaise Pascal – Clermont-Ferrand 2, 563 p. (codirecteur 50%, soutenance le 28 septembre2012)
  • ETTINGER, S. (2012) : Geomorphological impact of lahars on the southwestern flank of Cotopaxi Volcano, Ecuador : drainage system and alluvial fan. Thèse de Géographie de l’Université Blaise Pascal – Clermont-Ferrand 2, 511 p (codirecteur 50%, soutenance le 27 septembre2012)
  • ROUSSEL, E. (2011) : Réponses des glaciers et sandurs sud-islandais au réchauffement climatique post-Petit Âge glaciaire. Modalités et rythmes d’ajustement du continuum glacio-fluvial. Thèse de Géographie de l’Université Blaise Pascal – Clermont-Ferrand 2, 280 p. (codirecteur 50%, soutenance le 5 juillet 2011)

Publications

ACL - Articles dans des revues à comité de lecture

2017


  • Mayoral Pascual Alfredo, TOUMAZET Jean-Pierre, François-Xavier Simon, Vautier Franck et Peiry Jean-Luc« The Highest Gradient Model: A New Method for Analytical Assessment of the Efficiency of LiDAR-Derived Visualization Techniques for Landform Detection and Mapping », Remote Sensing, 9 (2), p. 120. DOI : 10.3390/rs9020120. https://hal.archives-ouvertes.fr/hal-01464694.
    Résumé : ALS-derived raster visualization techniques have become common in recent years, opening up new possibilities for subtle landform detection in earth sciences and archaeology, but they have also introduced confusion for users. As a consequence, the choice between these visualization techniques is still mostly supported by empirical knowledge. Some attempts have been made to compare these techniques, but there is still a lack of analytical data. This work proposes a new method, based on gradient modelling and spatial statistics, to analytically assess the efficacy of these visualization techniques. A selected panel of outstanding visualization techniques was assessed first by a classic non-analytical approach, and secondly by the proposed new analytical approach. The comparison of results showed that the latter provided more detailed and objective data, not always consistent with previous empirical knowledge. These data allowed us to characterize with precision the terrain for which each visualization technique performs best. A combination of visualization techniques based on DEM manipulation (Slope and Local Relief Model) appeared to be the best choice for normal terrain morphometry, occasionally supported by illumination techniques such as Sky-View Factor or Negative Openness as a function of terrain characteristics.
    Mots-clés : highest gradient model, landforms detection, Lidar, microtopography, spatial statistics, visualization techniques.
2016


  • Casado Ana, Peiry Jean-Luc et Campo Alicia M.« Geomorphic and vegetation changes in a meandering dryland river regulated by alarge dam, Sauce Grande River, Argentina », Geomorphology. DOI : 10.1016/j.geomorph.2016.05.036. https://hal.archives-ouvertes.fr/hal-01332432.
    Résumé : This paper investigates post-dam geomorphic and vegetation changes in the Sauce Grande River, a meandering dryland river impounded by a large water-conservation dam. As the dam impounds a river section with scarce influence of tributaries , sources for fresh water and sediment downstream are limited. Changes were inspected based on (i) analysis of historical photographs/imagery spanning pre-(1961) and post-dam (1981, 2004) channel conditions for two river segments located above and below the dam, and (ii) field survey of present channel conditions for a set of eight reference reaches along the river segments. Whilst the unregulated river exhibited active lateral migration with consequent adjustments of the channel shape and size, the river section below the dam was characterized by (i) marked planform stability (93 to 97%), and by (ii) vegetation encroachment leading to alternating yet localized contraction of the channel width (up to 30%). The present river displays a moribund, stable channel where (i) redistribution of sediment along the river course no longer occurs and (ii) channel forms constitute a remnant of a fluvial environment created before closing the dam, under conditions of higher energy. In addition to providing new information on the complex geomorphic response of dry-land rivers to impoundment, this paper represents the very first geomorphic assessment of the regulated Sauce Grande and therefore provides an important platform to underpin further research assessing the geomorphic state of this highly regulated dryland river.
    Mots-clés : Dryland rivers, Flow regulation, Geomorphic changes, Paso de las Piedras Dam, Sauce Grande River, Vegetation changes.


  • Casado Ana, Peiry Jean-Luc et Campo Alicia M.« Geomorphic and vegetation changes in a meandering dryland river regulated by alarge dam, Sauce Grande River, Argentina », Geomorphology. DOI : 10.1016/j.geomorph.2016.05.036. https://hal.archives-ouvertes.fr/hal-01332432.
    Résumé : This paper investigates post-dam geomorphic and vegetation changes in the Sauce Grande River, a meandering dryland river impounded by a large water-conservation dam. As the dam impounds a river section with scarce influence of tributaries , sources for fresh water and sediment downstream are limited. Changes were inspected based on (i) analysis of historical photographs/imagery spanning pre-(1961) and post-dam (1981, 2004) channel conditions for two river segments located above and below the dam, and (ii) field survey of present channel conditions for a set of eight reference reaches along the river segments. Whilst the unregulated river exhibited active lateral migration with consequent adjustments of the channel shape and size, the river section below the dam was characterized by (i) marked planform stability (93 to 97%), and by (ii) vegetation encroachment leading to alternating yet localized contraction of the channel width (up to 30%). The present river displays a moribund, stable channel where (i) redistribution of sediment along the river course no longer occurs and (ii) channel forms constitute a remnant of a fluvial environment created before closing the dam, under conditions of higher energy. In addition to providing new information on the complex geomorphic response of dry-land rivers to impoundment, this paper represents the very first geomorphic assessment of the regulated Sauce Grande and therefore provides an important platform to underpin further research assessing the geomorphic state of this highly regulated dryland river.
    Mots-clés : Dryland rivers, Flow regulation, Geomorphic changes, Paso de las Piedras Dam, Sauce Grande River, Vegetation changes.


  • Hortobágyi Borbála, Corenblit Dov Jean-François, Vautier Franck, Steiger Johannes, Roussel Erwan, Burkart Andreas et Peiry Jean-Luc« A multi-scale approach of fluvial biogeomorphic dynamics using photogrammetry », Journal of Environmental Management. DOI : 10.1016/j.jenvman.2016.08.069. https://hal.archives-ouvertes.fr/hal-01426679.
    Résumé : Over the last twenty years, significant technical advances turned photogrammetry into a relevant tool for the integrated analysis of biogeomorphic cross-scale interactions within vegetated fluvial corridors, which will largely contribute to the development and improvement of self-sustainable river restoration efforts. Here, we propose a cost-effective, easily reproducible approach based on stereophotogrammetry and Structure from Motion (SfM) technique to study feedbacks between fluvial geomorphology and riparian vegetation at different nested spatiotemporal scales. We combined different photogrammetric methods and thus were able to investigate biogeomorphic feedbacks at all three spatial scales (i.e., corridor, alluvial bar and micro-site) and at three different temporal scales, i.e., present, recent past and long term evolution on a diversified riparian landscape mosaic. We evaluate the performance and the limits of photogrammetric methods by targeting a set of fundamental parameters necessary to study biogeomorphic feedbacks at each of the three nested spatial scales and, when possible, propose appropriate solutions. The RMSE varies between 0.01 and 2 m depending on spatial scale and photogrammetric methods. Despite some remaining difficulties to properly apply them with current technologies under all circumstances in fluvial biogeomorphic studies, e.g. the detection of vegetation density or landform topography under a dense vegetation canopy, we suggest that photogrammetry is a promising instrument for the quantification of biogeomorphic feedbacks at nested spatial scales within river systems and for developing appropriate river management tools and strategies.
    Mots-clés : Fluvial biogeomorphologic feedbacks, Fluvial landforms, Multi-scale analysis, Riparian vegetation, Stereophotogrammetry, Structure from motion.
2015


  • Beauger Aude, Delcoigne Arnaud, Voldoire Olivier, Serieyssol Karen K. et Peiry Jean-Luc« Distribution of diatom, macrophyte and benthic macroinvertebrate communities related to spatial and environmental characteristics: the example of a cut-off meander of the River Allier (France) », Cryptogamie, Algologie, 36 (3), p. 1-33. DOI : 10.7872/crya/v36.iss3.2015.1. https://hal.archives-ouvertes.fr/hal-01170337.
    Résumé : Currently, a consensus has been reached to protect and restore cut-off meanders. Therefore, it is important to understand how these wetlands function. To our knowledge, the spatial and temporal distribution of both benthic diatoms and macroinvertebrates, associated with macrophytes communities, linked to the geomorphology, has not been studied extensively. In the upstream and intermediate zones, the low water temperature and the high conductivity revealed a connection with the groundwater. Moreover, the geomorphological riffle characterizing the intermediate zone created the same downwelling and upwelling processes as in running water, with a groundwater/hyporheic/surface water ecotone and produced physico-chemical differences between the upstream and the downstream zones and thereby modify the diatom, macroinvertebrate and macrophyte distribution. Downstream, water input from the main channel of the Allier River allowed the development of taxa observed in the River. All these hydrological connections and the sedimentation modified the physical, chemical and geomorphological characteristics, thereby, creating a gradient of water quality, influencing the distribution of the biotic communities.
    Mots-clés : /, cut-off, diatoms, geomorphology, Macroinvertebrates, macrophytes, meander, water.
2014

  • Beauger Aude, Peiry Jean-Luc, Lair Nicole et Voldoire Olivier« Ecological characterization of natural and impacted meander cut-offs of the River Allier using benthic macroinvertebrates », Ephemera, 14 (2), p. 83-106. https://hal.archives-ouvertes.fr/hal-01077881.
    Résumé : Today, the hydrological function and biodiversity of riverine secondary channels are generally recognized and managers tend to protect and restore them. In this study we focused on different parapotamal meander cut-offs. Six sites were examined, two of them being impacted by gravel extraction or deepened for halieutic activity. In order to test whether systematic differences in communities occurred upstream and downstream of the different sites, temperature and dissolved oxygen concentration were continuously monitored, other physical and chemical data were monthly measured and benthic macroinvertebrates were sampled in two seasons. Related to the abiotic data, in each site, water exchanges occurred between the river and / or the groundwater. In the unmodified sites, those few silted up displayed the greatest biodiversity with numerous EPT (Ephemeroptera, Plecoptera and Trichoptera) while in those largely silted, the habitat homogeneity induced a low biodiversity. In the two impacted sites, the upstream modification enhanced natural silting and few EPT were present while in the site largely open to the river, water quality, diversity and EPT richness remained high.
    Mots-clés : between-class Correspondence Analysis (bCA), habitats, physical and chemical monitoring.


  • Beauger Aude, Serieyssol Karen et Peiry Jean-Luc« Diatom distribution in natural and impacted cut-off meanders of the Allier River, France », Diatom Research, 29 (2), p. 119-145. DOI : 10.1080/0269249X.2013.863224. https://hal.archives-ouvertes.fr/hal-01077852.
    Résumé : basalt and downstream – sedimentary), differ in their degrees of infill or depth. In each region, three cut-off meanders were examined; one in each region was impacted by gravel extraction (upstream deepening) and halieutic improvement (downstream deepening), whereas the others were left in their natural state having different silt accumulations either almost cut-off from the river or less silted-up and more open to the river. The sites were monitored for one year for physical and chemical characteristics. Diatom samples collected in summer 2009 were examined along with their associated biocenosis. The two catchments, differing in geology, land-use and water quality, sheltered different diatom communities. Physical and chemical differences were recorded between up- and downstream zones of each cut-off meander due to both the influence of the groundwater (buffering the water temperature among others) and the periodic inflow from the main channel (increased oxygen saturation concentration in downstream end of the cut-off meanders, except for the impacted upstream zone which contained a lot of macrophytes). In the upstream reach (except for one site), the connection with the groundwater from the surrounding catchment, which acts as a hydro-geological reservoir, might explain the highest mineralization and water hardness recorded mainly in the upstream zone of the cut-off meander, and the presence of Pseudostaurosira subsalina (Hustedt) Morales and Thalassiosira weissflogii (Grunow) Fryxell & Hasle. For the downstream reach, in addition to up- and downstream differences, other factors came into play giving rise to different communities, for example, cattle trampling in the cut-off meander leading to the presence of hypereutrophic and polysaprobic taxa or the potential local re-emergence of mineral springs associated with brackish taxa. Moreover, the up- or downstream deepening also induced differences: the extraction of sediment nearer to the river created a system in which water input from the main channel flows in through a larger opening, inducing allochthonous processes. This increased the river’s influence, creating a renewal of earlier morphological and ecological conditions, whereas the gravel extraction that modified the upstream zone increased the influence of groundwater from the surrounding catchment on this area of the site and led to water conditions independent of the main channel. Furthermore, this study has provided an important picture of the environmental variables, mechanisms and processes that drive the distribution of diatoms within the cut-off meanders along the Allier River, which can can be applied in future paleo-environmental studies.
    Mots-clés : cut-off meanders, ecology, multivariate analyses, taxa distribution, water chemistry.
2013


  • Casado Ana, Hannah David, Peiry Jean-Luc et Campo Alicia« Influence of dam-induced hydrological regulation on summer water temperature: Sauce Grande River, Argentina. », Ecohydrology, 2013 (6), p. 523–535. DOI : 10.1002/eco.1375. https://hal.archives-ouvertes.fr/hal-01129395.
    Résumé : This study quantifies for the first time the influence of flow regulation on the river thermal behaviour of an ungauged basin located in central-eastern Argentina. A 30-day data set of continuous summer hourly data was assembled for eight water temperature gauging sites deployed along the main channel upstream and downstream from the impoundment. Analysis methods include descriptive statistics of daily temperature data, classification of diurnal regimes by relative differences in the ‘shape’ and the ‘magnitude’ of the thermographs (RSMC), and quantification of the climatic sensitivity of water temperature regimes using a sensitivity index. Results revealed that temporal fluctuations in water temperatures were linked to meteorological drivers; however, spatial variability in the shape and the magnitude of the thermographs revealed the effects of the dam in regulating river thermal behaviour downstream. Water temperatures immediately below the dam were reduced notably; diurnal cycles were reduced in magnitude, delayed in timing, and revealed overall climatic insensitivity and high temporal stability in regime shape. Dam effects persisted along the 15-km stretch monitored, although declined in the downstream direction. These findings provide new scientific understanding about the river water quality and inform river management about potential shifts in summer water temperature with great implications for the diversity and lifecycles of Neotropical river fauna. The use of the RSMC and sensitivity index approaches in water temperature assessment is novel and has wider applicability for quantifying river thermal regimes and their sensitivity to drivers of change over a range of temporal and spatial scales.
    Mots-clés : Flow regulation, regime shape and magnitude classification (RSMC), river water temperature, sensitivity index (SI), thermographes, ungauged basins.

C-ACT - Communications avec publication dans des actes

2015

  • Beauger Aude, Peiry Jean-Luc, Garreau Alexandre et Voldoire Olivier« Benthic diatom and macroinvertebrate communities from the impacted bypass channel of Poutès, upper Allier River (France): preliminary results before the dam removal. », in I.S. Rivers 2015, Lyon, France. https://hal.archives-ouvertes.fr/hal-01170126.
    Résumé : For the first time in France a dam is being removed in order to restore ecological and sediment continuity and to allow salmon migration. This modification of the dam of Poutès configuration allows the establishment of a long-term study. The first step is the evaluation of the geomorphological, sedimentary and ecological characteristics before the works in a reach of 21km including the bypassed section. This analysis is based on the study of diatoms and benthic macroinvertebrates collected upstream of the dam, in the bypassed section, and downstream of the penstock pipe release. The results show the impact of the dam on communities arising from a change in the water quality, but also habitats including the presence of very long and deep pools in the bypassed section, which alternate with rapids, which change the river dynamics of watercourse.
    Mots-clés : Benthic macroinvertebrates, bypass channel, Dam impacts, diatoms, longitudinal reach.

  • Peiry Jean-Luc, Voldoire Olivier et Sakho M« Ressources et qualité de l'eau sur le territoire de recherche de l'OHMi Tessékéré, Nord du Sénégal », in 3ème séminaire annuel du Labex DRIIHM, Aix en Provence, France : communication orale. (Labex DRIIHM). https://hal.archives-ouvertes.fr/hal-01245116.
    Résumé : Cette présentation fait le point des recherches en cours sur la ressource en eau et sa qualité physicochimique et microbienne sur le territoire de la Grande Muraille Verte sénégalaise. Sont examinées successivement les ressources en eau permanentes (forages profonds dans la nappe maastrichtienne) et les ressources intermittentes présentes dans les mares d'hivernage.
    Mots-clés : Grande Muraille Verte, ressource en eau, Sahel, Sénégal.
2014

  • Mayoral Pascual Alfredo, Peiry Jean-Luc, Berger Jean-François, Poux Matthieu, Milcent Pierre-Yves, Vautier Franck et Miras Yannick« An integrated geoarchaeological approach to assess human forcing on landscape: evolution of an Iron Age oppidum (Auvergne, France) » (présenté à XVII World UISPP congress, session 46 "Iron Age communities in western-central Europe: new approaches to landscape and identity), in Poster, September 1-6, Burgos, Spain : poster. https://hal.archives-ouvertes.fr/hal-01112300.
2012
2011

  • Casado Ana, Hannah David M., Peiry Jean-Luc et Campo Alicia M.« Effects of the Paso de las Piedras Dam on the thermal regime of the Sauce Grande River, Argentina » (présenté à Euromech Colloquium 523), in Ecohydraulics: linkages between hydraulics, morphodynamics and ecological processes in rivers, éd. par Claude Chomette et Johaness Steiger, Clermont-Ferrand, France : PUBP, p. 239-244. ISBN : 978-2-84516-529-8.

  • Ejarque Ana, Miras Yannick, Steiger Johannes, Beauger Aude, Voldoire Olivier, Peiry Jean-Luc, Vautier Franck et K. Serieyssol Karen« 2000 ans de paléodynamique fluviale et d’histoire du paysage dans la plaine alluviale de l’Allier révélés par l’analyse multi-proxy de 2 paléochenaux (Auvergne, France) » (présenté à Palynologie et diversités: marqueurs, milieux, méthodes, modèles, applications), in Poster, september 19-22, Meudon, France : poster. https://hal.archives-ouvertes.fr/hal-01112312.

C-COM - Communications orales dans une conférence nationale ou internationale

2017

  • Niang khoudia, Delay Etienne, Peiry Jean-Luc et Goffner Deborah D.« Perception de l'arbre en contexte Sahélien » (Communication orale), présenté à Séminaire LabEX DRIIHM, Aveiro, Portugal. (LabEX DRIIHM). https://halshs.archives-ouvertes.fr/halshs-01521743.
    Résumé : Dans le cadre de l’OHMi – Téssékéré et de l’ANR « Future Sahel », une recherche est conduite sur les usages des arbres en tant que pourvoyeur de ressources et vecteurs de services écosystémiques pour les acteurs locaux. En fonction du degré d’enclavement des zones concernées par l’étude, mais aussi des espèces botaniques accessibles et des pratiques culturelles et culturales locales qui leur sont associées, l’arbre sera utilisé (ou non) dans son intégralité (et peut-être différemment) par les hommes ou leurs troupeaux. Cette dépendance critique met l’ensemble des services écosystémiques liés aux arbres en tension et mieux comprendre la place qu’occupe l’arbre dans l’espace perçu et l’espace vécu des populations sahéliennes devient un facteur clef la gestion des ressources naturelles et plus particulièrement pour les stratégies de reboisement lancé dans le cadre de la grande muraille verte au Sénégal. Cette meilleure compréhension constitue également un des éléments clés de l’accroissement de résilience socio-environnementale dans une zone où cette végétation est fortement dégradée par le surpâturage et où la ressource végétale bien exploitée et valorisée pourrait beaucoup mieux pouvoir qu’actuellement au bien-être des populations et à leur résilience économique. Pour comprendre et explorer la manière dont les acteurs perçoivent les ressources liées aux arbres et la manière dont ils les mobilisent individuellement ou collectivement, un travail de recherche en cours. Réalisé par Khoudia Niang, ethnobotaniste et écologue, et animé par Deborah Goffner, il vise à mettre en évidence les relations et les types d’utilisation que les acteurs ont avec les arbres dans des systèmes socio-ecologiques contrastés situés sur le tracé de la Grande Muraille Verte (GMV). Ce travail prend la forme d’une enquête par questionnaires complétée d’entretiens en focus-groups. Il conduira à l’élaboration et à la formalisation d’une cartographie des « éco-socio-patches » basée sur les techniques de l’écologie du paysage et réalisée avec le concours de Jean-Luc Peiry, et à l’élaboration d’un modèle informatique individus-centrés, réalisé par Etienne Delay. Ces formalisations (spatiales et comportementales) au sein d’un modèle spatialement explicite permettront d’alimenter des ateliers participatifs avec les acteurs locaux durant lesquels le modèle sera confronté, validé, ou infirmé par les acteurs dans une approche itérative visant à traduire de manière acceptable les dynamiques spatio-temporelles qui sont à l’œuvre sur le tracé de la GMV. L’exploration du système, menée conjointement par entretiens et questionnaires et combinée avec un formalisme à base d’agents dans une approche participative, nous permettra d’explorer deux facettes de la perception des arbres en milieux sahéliens : i) identifier la manière dont les populations locales perçoivent les changements dans leur environnement et les répercussions que cela a sur leurs pratiques ii) projeter dans le temps ces changements de pratiques pour évaluer leurs impacts sur le système sahélien. Dans ce travail nous nous inscrivons dans une approche conceptuelle où l’événement social est le produit, du comportement d’un agrégat d’individus (individualisme méthodologique) et nous aurons abondamment recours aux sciences de la complexité (analyse des émergences, modélisation individu-centré).
    Mots-clés : arbres, ateliers participatif, modelisation.
2015

  • Hortobágyi Borbála, Burkart Andreas, Corenblit Dov, Peiry Jean-Luc, Steiger Johannes et Vautier Franck« 3D diachronic survey of riparian vegetation dynamics by photogrammetric methods: application of UAV and small airplane photographs » (Communication orale), présenté à EUGEO Budapest 2015, Budapest, Hungary. https://hal.archives-ouvertes.fr/hal-01201626.
    Mots-clés : 3D diachronic survey, Aerial Photographs, photogrammery, riparian vegetation dynamics, UAV.
2014

  • Casado Ana et Peiry Jean-Luc« The thermal regime of abandoned channels: a preliminary analysis towards a water temperature model for the Allier River, France » (communication orale), présenté à EGU General Assembly Conference Abstracts, Vienne, Autriche. http://adsabs.harvard.edu/abs/2014EGUGA.1612603C.
    Résumé : The growing recognition of the ecological and water quality significance of river water temperature led to a large number of studies assessing thermal processes in streams and rivers. Yet, thermal processes in abandoned channels, which play an important role in maintaining water quality and biological diversity in fluvial corridors, have received minor attention. This study evaluates water temperature regimes in three abandoned channels of the Allier River, France, and quantifies the regime sensitivity to climatic (air temperature) and hydrological (surface and subsurface flow) influence. Analysis was conducted at annual and daily scales, and at two distinct sections of each abandoned channel: (i) the downstream section, which is well connected to the main stream channel, and (ii) the upstream section, which is poorly connected to the main stream channel and hence subject to greater influence of subsurface flow. Annual and daily water temperature regimes for all channels and sections were classified based on relative differences in the 'shape' (timing) and the 'magnitude' (size) of the thermographs. The climatic and hydrological sensitivity of water temperature regimes was quantified using a Sensitivity Index. Analysis at the annual scale revealed relative similarity in patterns of thermal response over time, with clear differentiation between upstream and downstream channel sections in all sites. Water temperature regimes in the upstream channel sections were strongly linked to subsurface water temperature in terms of both timing and size of the annual thermograph; water temperature regimes in the downstream channel sections were more sensitive to air and river water temperature, especially regarding the timing of the annual regimes. Although annual regimes of water temperature exhibited distinct patterns that were similar across sites and over time, analysis of daily water temperature regimes revealed broad differences within and between sites. Day-to-day sequencing of similar classes of diurnal regime varied over the year, and between consecutive years. Furthermore, the direction and strength of climatic and hydrological sensitivity of daily water temperature regimes varied over time, and between sites. Temporal and spatial variability of diurnal regime class sequencing and sensitivity indicates complex climatic and hydrologic influence on water temperature variability, strongly related to the morphology of each site. Identifying thresholds of climatic and hydrologic influence, as well as temporal and spatial variations in the strength of climatic and hydrologic influence, is the key to further development of predictive models of water temperature in the abandoned channels of the Allier River.
2013
2012
2011
2010

CH - Chapitres d'ouvrage

2010

AP - Autres publications

2013
2010