Documents found
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1.More information
The study describes the implemented approach within the framework of a research-action dealing with interactions between socio-economical and ecological dynamics in a coastal area (Ouessant island, in the west of France). It describes how the companion modelling approach has encouraged the interdisciplinarity. The tools of the companion modelling (multi-agent model, simulations computing, role-playing game) were used to raise awareness with local people in landscape dynamics. Then they were mobilized for students to coastal issues and sustainable development. The scientific knowledge was disseminated by adapting the main research output, to local population and to young people. This was done in association with land managers and educators, and a reflective analysis the commitment of participants in these devices was undertaken. Through this experiment, most participants developed new skills related to interdisciplinarity, cooperation and communication, about the environmental management. This sudy also reveals the difficulties of appropriation of the approach by the partners. The appropriation of the stance of companion modelling seems then central at the same time to constitute a collective, but also to take up developed tools.
Keywords: modélisation d'accompagnement, éducation, interdisciplinarité, gestion environnementale, posture scientifique, companion modelling, education, interdisciplinarity research, environmental management, scientific stance
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The article raises the question of the political management of the pressures generated by the dynamics of local development on the resources of the island territories of the Iroise Sea, the island of Ouessant, the Molène archipelago and the island of Sein. A field survey consisted in 55 semi-directive interviews with three audiences: activity promoters, elected officials and managers; 254 questionnaires, 116 of which were from inhabitants and 138 from tourists, provided quantitative information on the mobilization of territorial resources. For the most part, these come from the sea. They are of course fishery resources, but also landscape resources, and even more generally geographical resources, in the sense that island life, as a living environment, constitutes a factor of attractiveness, at least the driving force behind the creation of identity and, indeed, society. The resources required today in the context of local development are natural, social, spatial and financial resources. The pressures that are exerted on the territory are expressed in two main forms: the secondarization of the habitat and the availability of land in general, on the one hand; and competition over fishery resources, on the other. The key element identified on the territory concerning the political management of these resources is a difficulty of communalization, the organization of the actors with the aim of managing the resources collectively. The marine conservation organizations do not currently seem to be able to significantly influence the management of resources, but they represent a tool, possibly an under-exploited territorial resource, in favor of this process of communalization.
Keywords: insularité, ressources communes, aire marine protégée, cadre de vie, insularity, common resources, marine protected area, living environment
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AbstractThis paper presents a cross analysis of the experiences of four social scientists involved in a companion modelling approach. As part of a research project of the Institut Français de la Biodiversité, four multi-agent systems and two role-playing games were developed on Biosphere Reserves. The purpose of the project was to explore the effects of natural land cover change from previously open to closed ecosystem structures and in turn, how changes in local landscapes stimulate the emergence of new social expectations and environmental values. This contribution follows earlier work on the study of complex systems, which recognizes the inherent complexity and uncertainty of natural resource management and thus the need to overcome the unproductive cleavage between the social and natural sciences. This paper aims to provide a framework for participatory and policy relevant research. .The reflection centers first on the place of social siences in the approach, the roles played by the researchers in the different contexts and the difficulties encountered, and continues on the relationship between society and nature.
Keywords: Modélisation d'accompagnement, système multi-agents, gestion de l'environnement, friche, réserve de biosphère, companion modelling, multi-agent system, environmental management, fallow, biosphere reserve
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Contamination of rainwater by pesticides was investigated by analyzing samples from 5 locations in Brittany (France). These sites were chosen on the basis of various characteristics including agricultural practices around the site, the direction of prevailing winds (west to east) and the proximity to heavily populated areas. The sites chosen were: Ile de Ouessant (a natural reserve without pesticide application), Landivisiau (a semi-natural zone), Plouay (a rural site with intensive agriculture, mainly cereals and vegetables), Ploufragan (a suburban site) and Rennes (an urban area surrounded by intensive agriculture and orchards). The pesticides to be monitored included the compounds most commonly used in Brittany. New molecules were added to this list to take into account new homologues or uses. Some organochlorines and pesticides with specific application modes were thus included in the list. Analytical techniques involved solid-liquid extraction procedures followed by GC-NPD, GC-ECD or GC-MS after prior derivatisation. Derivatisation was performed with heptafluorobutyric acid to detect urea and sulfonylurea herbicides. Quantification limits were about 5 ng/L for GC-ECD or GC-NPD, and 50 ng/L for molecules detected by GC-MS after derivatisation.Rain episodes were selected according to the prevailing meteorological conditions and the air mass trajectory. Only precipitation events greater than 6 mm were considered, in order to collect sufficient volume for analyses. Thirty-five samples (7 per location) were collected between 15 March and 15 July 2000, corresponding to various weather fronts.Six pesticides were detected: atrazine and its metabolite de-ethylatrazine (DEA), alachlor, desmethryne, lindane and its isomer (beta HCH). Among those detected most concentrations were below 100 ng/L but higher concentrations were occasionally detected during and after spraying in agricultural areas. Lindane was detected at low concentration (<10 ng/L) in several samples collected during different periods and locations. These results demonstrate chronic atmospheric contamination due to the presence of this substance even though its use has been banned in the Economic European Community (EEC) (e.g. in 1999 in France).The most frequently detected compound was atrazine, detected in 60 % of the samples. The presence of atrazine and its metabolite DEA in rainfall indicate chronic contamination of the atmosphere outside of spraying time (mid-March to mid-April). Detection of these compounds was generally limited to agricultural sites, and could also indicate transfer from agricultural areas during soil preparation for maize sowing. These hypotheses will be tested by monitoring atrazine in rainwater during a complete agricultural cycle. Important contamination by atrazine was detected during spraying time at agricultural locations, where concentrations ranged from 10 to 60 ng/L. Detection of alachlor was limited to application periods and rural sites, at levels ranging from 20 to 240 ng/L. However, amounts of alachlor were also detected in Ouessant, even though its use is banned on this isle. This presence was presumably due to the specific conditions of formation of the weather fronts that resulted in rainfall.Concentrations of pesticides in rainwater obtained in 2000 were generally lower than those described in literature or in a previous study done in Brittany. Alachlor and atrazine concentrations were compared to those of a previous study conducted in Brittany in 1996. The two sites chosen were Rennes in 2000 and Le Rheu in 1996. These two locations, separated by 5 km, were not significantly different since Rennes is directly downwind of Le Rheu. Pluviometry was very important in the year 2000, showing a 30 % increase in rainfall compared to the average from 1961-1990. The concentrations of pesticides in both years were also very different. During a year of normal rainfall (e.g., 1996) concentrations of pesticides in application periods were high, but they remained low during wet years (e.g., 2000). These differences could not be explained by a dilution effect - when fall-out was calculated (mg/ha) to correct for the dilution effect, the differences remained important. Maize surfaces (132 000 ha in 1996 compared to 128 000 ha in 2000) and the quantities of pesticides applied (580 tonnes in 1994 in Brittany compared to 350 tonnes for atrazine, and 263 tonnes in 1998 compared to 119 tonnes in 1994 for alachlor) were too similar to explain the differences observed in 1998. Photodegradation processes, which are more important during normal or dry years, should also favour higher concentrations in 2000 than in 1996. Rain concentrations and fallout observed in 2000 remained lower than those obtained in 1996. Thus, it can be concluded that atmospheric contamination is lower for wet years (e.g., 2000) than for normal or dry years (e.g., 1996). Soil humidity, high for wet years, favours the vertical migration of these substances to lower soil layers, reducing pesticide concentrations available to be transferred to the atmosphere.
Keywords: Pesticides, pluie, transfert air-sol, retombées massiques, Bretagne, Pesticides, rainwater, transfer, fallout, environmental analysis, Britanny
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8.More information
ABSTRACTOccurrence of erratic boulders on the floor of the English Channel and along the shorelines of the Massif Armoricain is a common feature. The distribution and the lithology of these erratics suggest ice rafting as the main transport mechanism and dispersion from local, regional and far away (basalt) sources areas. They were transported either by river ice, sea ice or icebergs. Drifting direction was controlled by prevailing winds assisted by tidal currents. One episode of shore rafting has been identified in shore formations and associated to a short transgression close to the end of the last interglacial. The observed relict sedimentary faciès is comparable to modern shore environments influenced by seasonal ice processes. Sea ice action on shore dynamics is believed to have taken place repeatedly during the Pleistocene along the coast of the English Channel. It could partly be responsible for the shaping of the shore platforms in the area.