Copyright 2020 - copyright UMR ESPACE-DEV - 2017

Nos dernières publications - Mars 2020

icone documentation publicationAlexandre Cyprien, Johary R., Catry ThibaultMouquet Pascal, Revillion C., Rakotondraompiana S., Pennober G. A Sentinel-1 based processing chain for detection of cyclonic flood impacts. Remote Sensing, 2020, 12 (2), p. art. 252 [18 p.] .

https://doi.org/10.3390/rs12020252

In the future, climate change will induce even more severe hurricanes. Not only should these be better understood, but there is also a necessity to improve the assessment of their impacts. Flooding is one of the most common powerful impacts of these storms. Analyzing the impacts of floods is essential in order to delineate damaged areas and study the economic cost of hurricane-related floods. This paper presents an automated processing chain for Sentinel-1 synthetic aperture radar (SAR) data. This processing chain is based on the S1-Tiling algorithm and the normalized difference ratio (NDR). It is able to download and clip S1 images on Sentinel-2 tiles footprints, perform multi-temporal filtering, and threshold NDR images to produce a mask of flooded areas. Applied to two different study zones, subject to hurricanes and cyclones, this chain is reliable and simple to implement. With the rapid mapping product of EMS Copernicus (Emergency Management Service) as reference, the method confers up to 95% accuracy and a Kappa value of 0.75.

hurricane ; cyclone ; flood ; Sentinel 1 time series ; change detection ; NDR ; SAR

Affiliation IRD : UMR 228 (ESPACE-DEV)

Lien permanent : https://www.documentation.ird.fr/hor/fdi:010077971

 

Satge FrédéricDefrance DimitriSultan BenjaminBonnet Marie-PauleSeyler FrédériqueRouché Nathalie, Pierron F., Paturel Jean-Emmanuel. Evaluation of 23 gridded precipitation datasets across West Africa. Journal of Hydrology, 2020, 581, p. art. 124412 [19 p.].

https://doi.org/10.1016/j.jhydrol.2019.124412

This study aims reporting on 23 gridded precipitation datasets (P-datasets) reliability across West Africa through direct comparisons with rain gauges measurement at the daily and monthly time scales over a 4 years period (2000-2003). All P-datasets reliability vary in space and time. The most efficient P-dataset in term of Kling-Gupta Efficiency (KGE) changes at the local scale and the P-dataset performance is sensitive to seasonal effects. Satellite-based P-datasets performed better during the wet than the dry season whereas the opposite is observed for reanalysis P-datasets. The best overall performance was obtained for MSWEP v.2.2 and CHIRPS v.2 for daily and monthly time-step, respectively. Part of the differences in P-dataset performance at daily and monthly time step comes from the time step used to proceed the gauges adjustment (Le day or month) and from a mismatch between gauge and satellite reporting times. In comparison to the others P-datasets, TMPA-Adj v.7 reliability is stable and reach the second highest KGE value at both daily and monthly time step. Reanalysis P-datasets (WFDEI, MERRA-2, JRA-55, ERA-Interim) present among the lowest statistical scores at the daily time step, which drastically increased at the monthly time step for WFDEI and MERRA-2. The non-adjusted P-datasets were the less efficient, but, their near-real time availability should be helpful for risk forecast studies (i.e. GSMaP-RT v.6). The results of this study give important elements to select the most adapted P-dataset for specific application across West Africa.

Precipitation datasets ; Reliability ; West Africa

Affiliation IRD : UMR 228 (ESPACE-DEV) ; UMR 050 (HSM)

Descr. géo. : AFRIQUE DE L'OUEST

Lien permanent : https://www.documentation.ird.fr/hor/fdi:010077958

 

Prolongation des appels à communication - International MangSES symposium

MANGSES

La date limite de soumission des résumés est prolongée jusqu'au 11 mai 2020 !
👉
Plus d'informations sur : https://mangses.sciencesconf.org/

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L'UMR Espace-Dev (Mayotte) co-organise une conférence internationale sur les mangroves. Cette conférence sur les systèmes socio-écologiques des mangroves (MangSES) mettra l'accent sur des présentations et des discussions interdisciplinaires. Une journée sur le terrain permettra de découvrir les enjeux et problématiques de certaines mangroves de Mayotte.

Date limite de l'appel à communications : 17 mai 2020

👉 Plus d'informations sur : https://mangses.sciencesconf.org/

Une serie de séminaires du groupe de recherche Ladiva à Mayotte

Des séminaires se sont déroulés au Centre universitaire de Mayotte et à la Réunion dans le cadre du groupe de recherche Ladiva, Littoraux, îles et Archipels – Diversité, VulnérabIlité/ Viabilité, Adaptabilité de l'UMR Espace-Dev. 
 
Mercredi 19 février : trois présentations ont été faites autour des concepts de perceptions, représentations sociales et attachement aux milieux/écosystèmes/paysages :

  • Angélique Bègue, doctorante à La Réunion : Perception et représentation sociale du paysage : intérêt et limites conceptuels et méthodologiques
  • Miranaharivola Rakotondrahanta, stagiaire M2 à Mayotte : Le concept d'attachement au lieu appliqué aux écosystèmes : dimensionnalités, intérêts et limites
  • Catherine Sabinot, chercheuse IRD en Nouvelle-Calédonie : Rendre compte des valeurs accordées au territoire marin via les espèces marines emblématiques : méthodes et outils

Jeudi 20 février, trois présentations autour du concept des savoirs (écologiques) locaux/traditionnels :

  • Clara Curmi, stagiaire M2 à Mayotte : Érosion, maintien et recomposition des savoirs écologiques locaux dans un contexte mondialisé
  • Matthieu Le Duff, maître de conférences à Mayotte : Connaissances, savoirs et pratiques autour des risques naturels en Nouvelle-Calédonie
  • Anliati Ahmed Abdallah, doctorante à Mayotte : Comment cartographier les savoirs écologiques locaux ?

Jeudi 27 févier  : 2 présentations

  • Esmeralda Longépée : ARESMA :Agirsur la resilience des systemes socio-écologiques de mangrove de Mayotte afin de favoriser leur préservation
  • Gilbert David  : Perceptions (locales versus global) et de comment les perceptions peuvent "driver" l'acceptabilité des MPA

seminaire Ladiva

Nos dernières publications - Février 2020

icone documentation publication

  1. Dimbour W. Pseudo S-asymptotically omega-periodic solution for a differential equation with piecewise constant argument in a Banach space. Journal of Difference Equations and Applications.

    http://dx.doi.org/10.1080/10236198.2019.1709179

    WOS:000507661200001

    In this paper, we give sufficient conditions for the existence and uniqueness of Pseudo S-Asymptotically omega-periodic solutions for a differential equation with piecewise constant argument in a Banach space. This result is obtained using the Pseudo S-asymptotically omega-periodic sequences.

    Affiliation IRD : UMR 228 (ESPACE-DEV)

  2. Gomes L. F., Vieira L. C. G., de Souza C. A., Bonnet Marie-Paule, de Almeida A. N. (2020). Environmental controls on zooplankton during hydrological periods of flooding and flushing in an Amazonian floodplain lake. Limnetica, 39 (1), 35-48.

    http://dx.doi.org/10.23818/limn.39.03

    WOS:000509685900004

    The hydrological regime exerts a strong control on environmental and biological variables in floodplains. To better understand this process, the present study evaluates the influence of environmental variables on zooplankton community structure, focusing on the hydrological variation of the flood pulse. For this purpose, we address the following questions: (i) What is the effect of hydrologic period on environmental characteristics and the structure of zooplankton community? (ii) Do environmental and biological similarities between sampling sites in a lacustrine ecosystem differ within flooding and flushing periods? (iii) How do zooplanktonic organisms respond to environmental gradients? To achieve this work, environmental and biological samples were collected in 20 sampling sites along the Lago 010077871 in March (flooding period) and September (flushing period) of 2013. While some zooplankton taxa showed relationship with some environmental variables, we estimate that the hydrological variation had a higher control over the taxonomic composition of Lago Grande do Curuai. Therefore, the strong flow that promotes connectivity between the habitats in the floodplain lake may also justify the similar pattern of heterogeneity between sampling sites for the zooplankton community in both periods, despite their environmental differences.

    Affiliation IRD : UMR 228 (ESPACE-DEV) ; (sans mention d'UMR)

    Copublication Sud avec : Brésil

    Lien Horizon FDI : http://www.documentation.ird.fr/hor/fdi:010077871

    Descr. géo. Horizon : BRESIL ; AMAZONE BASSIN ; LAGO GRANDE DO CURUAI

  3. Lejars C., Bouard S., Sabinot Catherine, Nekiridi C. (2019). Quand « l’eau, c’est le lien » : suivre l’évolution des réseaux d’eau pour éclairer les pratiques et les transformations sociales dans les tribus kanak = When "water is a link" : following water networks evolution to analyze social transformations in the . Developpement Durable et Territoires, 10 (3).

    http://dx.doi.org/10.4000/developpementdurable.15704

    WOS:000507392800009

    In New Caledonia, in the Kanak communities, "water is the link" ; the link between Heaven and Earth, between the Mountain and the Sea, but also between men and between clans. This article aims to show how the evolution of water networks management, from the "traditional" irrigation canals to the drinking water supply network, has transformed and still transforms uses of water in tribes and how these changes modify the links between men and tribe social organization. In the specific context of New Caledonian negotiated decolonization, focusing on techniques and technical changes around access and uses of the water show the impact of colonization and mining development on the management of the resource and on customary rules.

    Affiliation IRD : UMR 183 (G-EAU) ; UMR 228 (ESPACE-DEV)

    Lien Horizon FDI : http://www.documentation.ird.fr/hor/fdi:010077795

    Descr. géo. Horizon : NOUVELLE CALEDONIE

  4. Pontie M., Jaspard E., Friant C., Kilani J., Fix-Tailler A., Innocent C., Chery D., Mbokou S. F., Somrani A., Cagnon B., Pontalier P. Y. (2019). A sustainable fungal microbial fuel cell (FMFC) for the bioremediation of acetaminophen (APAP) and its main by-product (PAP) and energy production from biomass. Biocatalysis and Agricultural Biotechnology, 22.

    http://dx.doi.org/10.1016/j.bcab.2019.101376

    WOS:000509762700011

    A fungal biofilm of Scedosporium dehoogii was successfully elaborated and used as a bio anode in a microbial fuel cell device. The cathode was a carbon felt electrochemically modified by electrodeposition of a film of poly-Ni(II) tetrasulphonated phthalocyanine (poly-NiTSPc). The elaborated biofilm, formed by electrodeposition of a suspension of Scedosporium dehoogii worked to catalyze acetaminophen (APAP) oxidation in the anode. The optimal potential during the electrodeposition process was found to be 0.8 V vs. saturated calomel electrode (SCE) with a thickness of 3.5 +/- 0.2 mu m. The fabricated fungal microbial fuel cell (FMFC) proved to be an efficient fuel in acetaminophen with highly stable output performances offering a power density of 50 mW m(-2) under an electromotive force of +550 mV in physiological conditions. The biodegradation of PAP, the main APAP by-product from bacterial biodegradation, was also studied and the optimal resistance from the usual polarization curves was 3.000 Ohm. Finally, the biodegradation of ligno-cellulosic materials such as bagasse, rapeseed, cellulose and lignin by Scedosporium dehoogii was successfully tested in Petri dishes. The growth of the fungus using these biomaterials as substrates followed the order: bagasse > rapeseed > cellulose > lignin. The FMFC was tested in the presence of natural lignin from sugarcane bagasse and complete degradation of the lignin by S. dehoogii biofilm was achieved with a power density of 16 mW m(-2).

    Affiliation IRD : UMR 228 (ESPACE-DEV)

    Copublication Sud avec : Cameroun ; Arabie Saoudite

  5. Tamarin O., Rube M., Lachaud J. L., Raimbault V., Rebiere D., Dejous C. (2020). Mobile Acoustic Wave Platform Deployment in the Amazon River: Impact of the Water Sample on the Love Wave Sensor Response. Sensors, 20 (1).

    http://dx.doi.org/10.3390/s20010072

    WOS:000510493100072

    This paper presents an experimental platform allowing in situ measurement in an aqueous medium using an acoustic Love wave sensor. The aim of this platform, which includes the sensor, a test cell for electrical connections, a microfluidic chip, and a readout electronic circuit, is to realize a first estimation of water quality without transportation of water samples from the field to the laboratory as a medium-term objective. In the first step, to validate the ability of such a platform to operate in the field and in Amazonian water, an isolated and difficult-to-access location, namely, the floodplain Logo Do Curuai in the Brazilian Amazon, was chosen. The ability of such a platform to be transported, installed on site, and used is discussed in terms of user friendliness and versatility. The response of the Love wave sensor to in situ water samples is estimated according to the physical parameters of Amazonian water. Finally, the very good quality of the acoustic response is established, potential further improvements are discussed, and the paper is concluded.

    Affiliation IRD : UMR 228 (ESPACE-DEV)

 

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