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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

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

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

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