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Longtemps délaissées, les zones humides bénéficient en France de politiques actives de conservation. Par une méthodologie de recherche participante, les caractéristiques et enjeux des jugements des experts impliqués dans la mise en œuvre de ces politiques sont analysés. Malgré des atours purement techniques, ces jugements engagent une compréhension projective et chargée de valeur de la conservation des zones humides. Cette analyse appelle à une refonte des cadres qui structurent le travail des experts. Numerous policies are devoted to protecting wetlands. This is the case in many countries around the world, and more specifically in France, where numerous environmental regulations and policy frameworks focus on wetlands. Using a participating research methodology, this article analyses the features and stakes of expert judgments involved in the implementation of these policies. Although these judgments superficially seem to be entirely technical, they involve a projective, value-laden understanding of the endeavour to conserve wetland. This analysis suggests rethinking the tools used to supervise expertise.

In the current context of promoting sustainable development, the issue of managing vegetation fires has become worrying and involves many issues related to climate change, environmental degradation and civil protection. In Cameroon, the regulatory provisions on fires practices, mainly restrictive, have been mostly ineffective because they are not based on reliable indicators of monitoring the phenomenon over time and space. In fact, the determination of the period of so-called “early” and tolerated fires relies on very static variables such as the beginning of the dry season, calculated over a long series of rainfall data (20 years and more). However, the beginning and severity of the fire season can vary significantly from year to year, espe-cially in the current context of climatic variability. Furthermore, Cameroon’s commitment to climate stabilization mechanisms initiated at the international level requires timely data on greenhouse gas emissions, much of which are derived from biomass burning in subtropical Africa. In short, figures on the distribution of wildfires are necessary to better enforce the regulations. However, this distribution is variable, both seasonally and annually, depending on vegetation type, land use patterns, and climate cycles; this further complicates the assessment of the actual frequen-cy of fires throughout the territory. The formulation and implementation of a fire prevention plan requires consideration on fire’s history in terms of location, seasonality and social justification.Attempts to monitor fires through field campaigns have shown their limitations because of the ephemeral nature of the vegetation combustions and the inaccessibility of some affected areas. The objective of this contribution is to characterize Cameroon’s pyroregions using data from low-resolution imagery, to support the implementation of wildfire regulations. For the monitoring of a phenomenon as ephemeral and repetitive as wildfires, the satellite imagery approach has the advantage of offering a wide view and a certain repetitiveness of the obser-vations making it possible to evaluate the phenome-non on various scales of time and space.Active fire pixels covering part or the whole globe are produced from low spatial resolution satellite imagery and used by different regional or global initiatives. The comparison of the different series available (MODIS active fire, ATSR, NOAA-AVHRR, TRMM-VIRS), however, revealed signifi-cant statistical differences. Table 1 presents the correlation coefficients between the series. It therefore becomes necessary to carry out, before use, their validation using high spatial resolution imagery (LANDSAT TM or ETM). For this purpose, eight Landsat ETM scenes covering different ecosystems were acquired (Plate 1). Three color composites 6-5-3 confirmed the potential of Landsat imagery in highlighting the spaces affected by fires (Plate 2). The confrontation of the Landsat fire zones and the low spatial resolution data made it possible to validate the MODIS active fire pixels as the best adapted to the monitoring of vegetation burning in Cameroon, with a statistic precision of 62%. Daily MODIS active fire data for the period from 2001 to 2010 were compiled by decade and spatialized. After conclusive correlation tests between explanatory variables and fire occurrences, the Principal Component Analysis ultimately structured the fire zone in the Cameroonian territory.The distribution over time of active fires indicates that the season of vegetation burning in Cameroon goes from October to April, with peaks in December. There is also, over the months, a North-South and then, South-North shift of the fire concentration zone (Plate 3). The analysis of the factors of regio-nalization of the fires shows a direct and preponderant influence of the vegetation taken in its nature, its density and its state of humidity (Plate 4). In the south, the fires follow the margins of the forest, always too wet to favor the extension of the flames. The rare fires observed are mainly related to agricultural clearance (Table 2). They thus appear as indexes for identification of degraded forests. It is in Sudanian zone that the fires are the most nume-rous and spread over time. Here, the abundant and conducive vegetation allow the spread of fires in the dry season. In the Sahelian zone, only the flooded yaere carries dense herbaceous vegetation that can feed large fires up to the heart of the dry season. Elsewhere, the scarcity of grass cover due to cli-matic aridity and livestock harvesting hampers the spread of fires. Histograms of active fires observed in main vegetation units are displayed at Figure 1.Based on the fire density, the beginning and the spreading of the fire season, the Cameroonian territory is subdivided into 8 pyroregions (Plate 5), whose characteristics can be taking into account to reduce significantly the inconsistencies observed in the implementation of regulations provisions on fires practices. This partition of the space into pyroregions also constitutes an initial framework, in which more detailed observations can be carried out., Dans le contexte actuel de promotion du développement durable, la problématique de gestion des feux de végétation est devenue préoccupante et comporte de nombreux enjeux liés au dérèglement climatique, à la dégradation des milieux et à la protection civile. Au Cameroun, les dispositions règlementaires édictées en la matière se sont montrées le plus souvent inefficaces et inopérantes, parce que non fondées sur des indicateurs fiables de suivi du phénomène dans le temps et dans l’espace. L’objectif de cette contrib-tion est de caractériser les pyrorégions du Cameroun à l’aide des données issues de l’imagerie à basse ré-solution spatiale, en vue de formuler des éléments d’appui pour leur meilleure gestion au Cameroun.L’évaluation des données produites dans le cadre de diverses initiatives visant la mise à disposition des don-nées spatiales sur les feux montre que les pixels de feux actifs MODIS sont bien adaptés au suivi des espaces affectés par les feux de végétation. L’analyse des facteurs de régionalisation des feux montre une influence directe et prépondérante de la végétation, prise dans sa nature, sa densité et son état d’humidité. Les facteurs anthropiques n’agissent qu’indirectement à travers la disponibilité et la continuité de la végétation combustible.Sur la base de la densité des feux, du début et de l’étalement de la saison des feux, le territoire camerounais est subdivisé en 8 pyrorégions dont la prise en compte des caractéristiques peut permettre de réduire considérablement les incohérences constatées dans l’opérationnalisation de la règlementation. Cette partition de l’espace en pyrorégions constitue par ailleurs un cadre initial de travail, dans lequel des observations plus fines peuvent être conduites en vue d’évaluer de façon plus précise les émissions de gaz à effet de serre (GES) résultant des combustions végétales.

This thesis examines the role and the impact of pressure groups in environmental regulation process.Indeed, in recent years, scientific controversies (GMO, Médiator, shale gas) have lead us to wondermore about their effects, especially when the achievement or the extent of environmental damage and /or health are uncertain. In particular, in the context of a market approval process of a potentialdangerous product, we assume that two pressure groups are fighting, representing respectively theinterests of industry and those of victims of damage: the first campaigns for its authorization and thesecond for its prohibition. In this context, information available to the voluntary regulator is important.Assuming that he is unaware of the magnitude of the damage ex ante, we question the relevance ofpaying attention to lobbyists to take a socially efficient decision, in a case where the industrial groupfaces a responsibility system, ex post. However, the application of this system is imperfect, because ofthe insolvency of the industry or by the fact either that the industrial group responsibility is notrecognized, or that the victims group does not request compensation for damages. When the regulatortakes his decision based on a contest, the introduction of a sequential contest in which the outsidermoves first is socially preferable. Moreover, the conditions under which the regulator has to payattention to the pressure groups rather than taking his decision based on a cost-benefit analysis, usinghis prior beliefs on damage, are characterized., Cette thèse étudie le rôle et l’impact des groupes de pression dans le processus d'adoption d'uneréglementation environnementale. En effet, les controverses scientifiques de ces dernières années(OGM, Médiator, gaz de schiste) nous interrogent sur leurs effets, notamment lorsque la réalisation oul'ampleur d'un dommage environnemental et / ou sanitaire sont incertaines. En particulier, lors d'unedemande d'Autorisation de Mise sur le Marché d'un produit potentiellement dangereux, noussupposons que deux groupes de pression s'affrontent, représentant, respectivement, les intérêts d'uneindustrie et ceux des victimes d'un dommage : le premier milite pour son autorisation et le second pourson interdiction. Dans ce contexte, l'information détenue par le régulateur bénévole est primordiale.Présumant qu’il est inconscient, ex ante, de l'ampleur du dommage, nous nous interrogeons sur lapertinence d'écouter les groupes de pression afin de prendre une décision socialement efficace dans lecas où le groupe industriel fait face à un système de responsabilité, ex post. Pourtant, l'application dece système est imparfaite, suite à l'insolvabilité de l'industriel ou par le fait qu'il ne soit pas poursuiviou reconnu coupable. Lorsque le régulateur prend sa décision après l'affrontement des groupes depression, la mise en place d'un contest séquentiel, avec l'outsider qui joue en premier, est socialementpréférable. Par ailleurs, les conditions sous lesquelles le régulateur doit accorder son attention auxgroupes de pression plutôt que prendre sa décision sur la base d'une analyse coûts-bénéfices, utilisantses croyances a priori sur le dommage, sont caractérisées

This report is the product of a comprehensive study on Benin. It highlights the country s geographical and economic situation and concentrates in particular on environmental conditions and the challenges facing Benin. This report covers the financing of priority environmental activities, as well as allocations to programs designed to improve the environment and living conditions of the population. The environmental analysis of Benin seeks to help the Government integrate the environment into policy formulation by analyzing cross-cutting aspects and the challenges of implementing sound environmental management, and creating a platform for strengthening the country s capacities in order to facilitate sustainable natural resource and environmental management. To this end, a number of measures have been recommended, among them the establishment of effective policies and institutions based on sound governance and improved effectiveness, and the mobilization of financing for environmental protection and natural resource management. The study includes the analysis of a case study on three cities: Porto-Novo, Cotonou, and Parakou, and examines the impact of environmental problems and environmental management challenges on these cities.

This paper reviews in a non-technical presentation some of the theoretical foundations of the Porter Hypothesis that argues that strict environmental regulations may increase the profits of industries that have to respect them. After a short presentation of the hypothesis, some of the arguments based on firms’ organizational failures are presented. Arguments based on market failures are then discussed. The main conclusions of this review are: i) the Porter Hypothesis requires the presence of at least one distortion beside the environmental externality, ii) the type of environmental regulations leading to the Porter result depends upon the nature of the interacting distortions. Furthermore, reaching the optimum will usually require using several regulatory instruments, iii) empirical testing of the Porter hypothesis has to allow for the presence of multiple distortions., Cet article présente de manière non technique certains des fondements théoriques possibles de l’hypothèse de Porter selon laquelle, des réglementations environnementales strictes peuvent améliorer le profit des industries qui y sont soumises. Après une brève présentation de l’hypothèse, les arguments basés sur l’existence d’imperfections au sein de l’entreprise sont passés en revue. Les imperfections du marché susceptibles d’éventuellement justifier l’hypothèse de Porter sont ensuite discutées. Les principales conclusions de ce survol sont : i) l’hypothèse de Porter requiert l’interaction de l’externalité environnementale avec au moins une autre source de distorsions, ii) le type d’intervention publique qui peut aboutir à un effet à la Porter dépend de la nature des distorsions qui interagissent. L’atteinte de l’optimum peut exiger l’usage de plusieurs instruments, iii) l’exploration empirique de l’hypothèse de Porter doit, pour être valide, autoriser la présence de ces multiples distorsions.