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Probabilistic cellular automata are extended stochastic systems, widely used for modelling phenomena in many disciplines. The possibility of controlling their behaviour is therefore an important topic. We shall present here an approach to the problem of controlling such systems by acting only on the boundary of a target region. In particular we are interested in optimal control, which is rather demanding in computational terms, so we present also a less demanding suboptimal method. Finally, we present an example of optimal control with avoidance.

Affiliation IRD : UMR 228 (ESPACE-DEV) - Copublication Sud avec : Mexique

The article analyses urban projects and governance of urban planning in a fast growingurban community (Grand Narbonne, Aude, France), focusing on the approach of the local stakeholders, between interest and distrust, about landscape considered as a dimension of the urban project and as a tool for collective thinking about urban planning. Trying to overcome what appears to be a sort of consensus about the importance of the landscape dimension due to the European Landscape Convention and to the evolution of the French legislative framework, the paper tries to highlight the processes of emergence and diffusion of a collective "culture of landscape" applied to urban planning. The part played in these processes by the regional natural park of the "Narbonnaise en Mediterranee" is thoroughly analysed, as well as the limits of its actions. The study also takes into account the strengthening of the intercommunal institutions, which broadens the local system of governance.

Affiliation IRD : UMR 228 (ESPACE-DEV) - Lien Horizon FDI
Descr. géo. Horizon : MEDITERRANEE ; NARBONNAISE PARC

Amazonian floodplains form complex hydrological networks that play relevant roles in global biogeochemical cycles, and bacterial degradation of the organic matter in these systems is key for regional carbon budget. The Amazon undergoes extreme seasonal variations in water level, which produces changes in landscape and diversifies sources of organic inputs into floodplain systems. Although these changes should affect bacterioplankton community composition (BCC), little is known about which factors drive spatial and temporal patterns of bacterioplankton in these Amazonian floodplains. We used high-throughput sequencing (Illumina MiSeq) of the V3-V4 region of the 16S rRNA gene to investigate spatial and temporal patterns of BCC of two size fractions, and their correlation with environmental variables in an Amazon floodplain lake (Lago Grande do Curuai). We found a high degree of novelty in bacterioplankton, as more than half of operational taxonomic units (OTUs) could not be classified at genus level. Spatial habitat heterogeneity and the flood pulse were the main factors shaping free-living (FL) BCC. The gradient of organic matter from transition zone lake -Amazon River was the main driver for particle-attached (PA) BCC. The BCC reflected the complexity of the system, with more variation in space than in time, although both factors were important drivers of the BCC in this Amazon floodplain system.

Affiliation IRD : UMR 228 (ESPACE-DEV) ; (sans mention d'UMR) - Copublication Sud avec : Brésil - Lien Horizon FDI
Descr. géo. Horizon : BRESIL ; AMAZONE ; GRANDE DO CURUAI LAC

Five case studies are presented, all located in highland regions of South Asia and inhabited by ethnic minorities (India, Nepal, China, Laos, Vietnam), in order to analyze the consequences of narratives, actions and transformations of governance via the landscape. How does the landscape become, through tourism, a "way of seeing" territories, how does it foster renewed governance of these territories? After having shown how the use of landscape resources leads to the development of a landscape culture via tourism, we will see that the landscape occupies various places in the processes of territorial governance. A final typology will be based on three criteria : consciousness of the landscape, governance process, and tourism expansion.

Affiliation IRD : UMR 228 (ESPACE-DEV) ; UMR 215 (Prodig) - Copublication Sud avec : Inde - Lien Horizon FDI
Descr. géo. Horizon : NEPAL ; INDE ; CHINE ; LAOS ; VIET NAM

Built on the basis of a literature review on colonial history, contemporary socio-spatial dynamics and an analysis of the electoral results of the last thirty years in New Caledonia, this article shows the long process that has led to self-determination, following a long period of hard colonization and decolonization in trompe-l'oeil. "Rebalancing", which has been in operation for more than three decades, has difficulty reducing differences between communities in a nickel-dominated territory with an economy suffering from Dutch disease. On 4 November 2018, a small and unprecedented electorate was asked the following question: "Do you want New Caledonia to achieve full sovereignty and become independent?". Although broad, the victory of the "No" by 56.7% against 43.3% for the "Yes" is closer than expected and it was the independentists who gave the impression that they had won this referendum. The spatial distribution of the "Yes" and "No" is the copy of the distribution of Kanak and Europeans, revealing the deep divisions of this society.

Affiliation IRD : UMR 228 (ESPACE-DEV)

Reservoirs are closely related to anthropic activities, and quantifying the long-term dynamics of surface water in reservoirs could be useful for decision-makers to improve the actual strategies of reservoir management. This study used the global Moran's I index, modi?ed Normalized Difference Water Index (MNDWI) and a total of 596 Landsat images during 1985-2018 for tracking the annual dynamics of water extent in the process of water shrinkage and expansion in Guanting Reservoir, China. Landscape metrics related to the area, elongation, fragmentation, and edge complexity of surface water in reservoir landscape were computed for tracking the annual dynamics of surface water patterns. Statistical comparison between the results of global Moran's I index and landscape metrics indicates that except for the complexity of water and non-water edge, global Moran's I index can successfully estimate the dynamics of the area, elongation and fragmentation of surface water in the reservoir. This study proposed a continuous approach of long-term monitoring of surface water patterns using spatial autocorrelation that might be used in the areas where the surface water extraction is difficult and water dynamics are complex.

Affiliation IRD : UMR 228 (ESPACE-DEV) - Copublication Sud avec : Brésil ; Chine - Lien Horizon FDI
Descr. géo. Horizon : CHINE ; PEKIN ; GUANTING

Achieving food security goals in West Africa will depend on the capacity of the agricultural sector to feed the rapidly growing population and to moderate the adverse impacts of climate change. Indeed, a number of studies anticipate a reduction of the crop yield of the main staple food crops in the region in the coming decades due to global warming. Here, we found that crop production might have already been affected by climate change, with significant yield losses estimated in the historical past. We used a large ensemble of historical climate simulations derived from an atmospheric general circulation model and two process-based crop models, SARRA-H and CYGMA, to evaluate the effects of historical climate change on crop production in West Africa. We generated two ensembles of 100 historical simulations of yields of sorghum and millet corresponding to two climate conditions for each crop model. One ensemble is based on a realistic simulation of the actual climate, while the other is based on a climate simulation that does not account for human influences on climate systems (that is, the non-warming counterfactual climate condition). We found that the last simulated decade, 2000-2009, is approximately 1 degrees C warmer in West Africa in the ensemble accounting for human influences on climate, with more frequent heat and rainfall extremes. These altered climate conditions have led to regional average yield reductions of 10-20% for millet and 5-15% for sorghum in the two crop models. We found that the average annual production losses across West Africa in 2000-2009 associated with historical climate change, relative to a non-warming counterfactual condition (that is, pre-industrial climate), accounted for 2.33-4.02 billion USD for millet and 0.73-2.17 billion USD for sorghum. The estimates of production losses presented here can be a basis for the loss and damage associated with climate change to date and useful in estimating the costs of the adaptation of crop production systems in the region.

Affiliation IRD : UMR 228 (ESPACE-DEV) - Lien Horizon FDI 
Descr. géo. Horizon : AFRIQUE DE L'OUEST

Réunion de clôture du projet ODYSSEA - 7-8 octobre 2019 - Université de Brasilia

IMG 9349La réunion de clôture du projet Odyssea s'est déroulée pendant deux jours à l'universtié de Brasilia.

La première journée a été consacrée à un bilan des résultats par Work Package et par site de recherche (Santarém, Nord Pará, BR-163, Manaus,..) entre chercheurs du projet en concluant par un café mondial pour une auto-évaluation du projet et des travaux de groupe pour les perspectives.

La seconde journée, plus institutionnelle, a rassemblé des représentants de l´ambassade de France, de l´ambassade du Portugal, de l´AFD et de la délégation de l´UE au Brésil avec des acteurs de la société civile de tous les états de l´Amazonie légale (syndicats ruraux, services municipaux, fondation, ONG, universités) et chercheurs autour d´une question principale « Comment mobiliser la sciences pour répondre aux défis des sociétés en Amazonie ? ». Le programme organisé sous la forme de tables rondes a permis de donner la parole à différents types d’acteurs sociaux qui ont pris part à nos recherches et apporter leur éclairage sur les défis à relever pour une science impliquée.

Atelier CES – ART GeoDEV - Toulouse

actu atelierARTGeoDEV 696x406Un atelier de réflexion entre la coordination de l’ART et les responsables de Centres d’Expertise Scientifique (CES) du Pôle Theia a eu lieu dans les locaux du CESBIO, à Toulouse le 1er octobre 2019. Cette journée d’échange proposée par les animateurs de l’ART GeoDEV a réuni une quarantaine de participants.

Elle avait pour finalité d’approfondir et de diversifier les interactions entre les Centres d’Expertise Scientifique et l’ART GeoDEV dans les territoires et pays du sud :

  • Faire connaitre l’ART, son mandat, ses objectifs, ses périmètres d’activité, ses projets en cours ou à venir, les services qu’il fournit ;
  • Faire connaître les activités de CES dans des territoires du sud ;
  • Partager des informations et des retours d’expériences sur les activités menées en collaboration avec des partenaires du sud ;
  • Identifier et planifier des modalités d’interactions CES – ART GeoDEV en réponse à des besoins spécifiques de CES ou de partenaires au sud ;
  • Initier une réflexion prospective commune autour des articulations entre CES et ART, et identifier les collaborations possibles de différents CES à un projet de développement de l’utilisation de l’information geo-spatiale au sud.

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Sortie du film "Le Palmier babaçu aujourd'hui, et demain ?"

Capture decran 2019 10 11 a 13.21.40Le palmier babaçu est originaire de la forêt amazonienne. On le retrouve aujourd'hui dans les nouveaux pâturages destinés aux troupeaux. Son comportement actuel est considéré comme envahissant par les agriculteurs qui souhaitent l’éliminer, alors que d’autres acteurs, souvent des femmes sans terre, l’utilisent pour subvenir à leurs besoins.


Izildinha Miranda Professeure en écologie végétale à l’UFRA de Belém, Danielle Mitja chercheuse en botanique/écologie et Eric Delaître Ingénieur en télédétection à l'IRD, leurs équipes, leurs partenaires et étudiants tentent de comprendre le caractère envahissant du babaçu tout en sensibilisant les agriculteurs sur ses nombreux bienfaits. Les divers protagonistes du film s’expriment librement pour expliquer leurs travaux, leurs soucis, leurs projections pour le futur.

 

 

 

Réalisation : Luc Markiw, IRD Image
Montage : Carolina Lutenberg
Conseillers scientifiques : Danielle Mitja chercheuse en botanique/écologie IRD, UMR228 - ESPACE-DEV Eric Delaître Ingénieur en télédétection IRD, UMR228- ESPACE-DEV
Musique : Jérôme Rossi

 

Voir le film en version française
Voir le film en version brésilienne

 

Colloque Les îles à venir - 17-19 octobre 2019 - Brest

les iles2019

Îles 2019 est une manifestation scientifique et culturelle, qui se tiendra la semaine du 14 au 19 octobre 2019 à Brest et les îles de l'Iroise.

Cette semaine sera consacrée aux îles du monde. Les îles, territoires de la mémoire, mais aussi espaces en devenir, constituent des espaces spécifiques qui interrogent les scientifiques de toutes disciplines, inspirent les artistes et mobilisent les collectivités.

A cette occasion, le colloque scientifique pluridisciplinaire « Les îles à venir » est organisé à Brest du 17 au 19 octobre. L'UMR Espace-Dev,partenaire de cette manifestation, sera représentée avec la participation de plusieurs chercheurs.

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UMR ESPACE-DEV
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Guyane : IRD - 0.275 Km Route de Montabo - BP 165 - 97323 Cayenne cedex
Nouvelle-Calédonie : Centre IRD Anse Vata - BPA5 98848 Nouméa Cedex
Réunion : Université de la Réunion
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