Compte-rendu de mission en RCA de M. Guillaume Cornu du 06 au 20/11/2015

La mission de M. Cornu en RCA a eu lieu du 6 au 20 novembre 2005. Elle correspondait à la session A3 " Renforcement Informatique " de l'annexe B du contrat de service et fait suite à l'ordre d'exécution du contrat, à partir du 18 juillet 2005, pour une période de 11 mois. Durant les deux semaines l'expert a dispensé une formation axée sur le renforcement des compétences en informatique et principalement à la saisie et au traitement de données avec le logiciel Excel. La prochaine mission de P. Dubus, correspondant à la session B1 " Bases de données et Access " a été programmée du 4 au 18 décembre 2005. (Résumé d'auteur

Forest degradation estimation using remote sensing: a case study on Central African Republic

Human activities within tropical rain forests provoke perturbations and degradation. The capacity to measure the extent of these damages is essential for calculating carbon emissions under the REDD+ process. Remote sensing is a powerful tool to provide such information (logging, mining, infrastructure building). Various techniques to identify and quantify forest degradation have been used so far. One step further is to link in-time degradation and past-time degradation to document the recovery of ecosystems after logging. For this, we propose a processing chain adapted to Landsat and Spot imageries. Post-processing is devoted to extract degradation information using specific algorithms. A spatial index, sized to low resolution radiometer, is implemented to render the actual and past degree of degradation. It is then related to continental land cover maps to get insight in the actual state of particular forest categories. This tool is developed in the framework of the CoForChange program (http://www.coforchange.eu/project) which general objective is to predict changes in forest and tree species distribution in the Congo Basin due to global change and to elaborate decision-making tools. The presentation is focused on an example in real time and in real size. It covers all the moist forest of Central African Republic at a yearly time-scale during ten years of Landsat images archive. (Résumé d'auteur

Aménager les forêts tropicales de production : quelques logiciels d'aide à la décision [fiches de compétences forêts SIA 2011]

Outil privilégié de la gestion durable, le plan d'aménagement cherche le plus souvent à concilier la production de bois et la conservation des multiples services rendus par la forêt. Le Cirad a développé une expertise unique en la matière. Il propose des méthodes et des outils d'aide à l'aménagement, fondés sur des scénarios comparatifs et des itinéraires techniques adaptés au cadre législatif et réglementaire de chaque pays. Ces outils offrent aux acteurs concernés, publics ou privés, les moyens de faire les choix de gestion les plus pertinents face aux enjeux actuels. (Résumé d'auteur

FrontlinesSMS as an early warning network for human-wildlife mitigation: Lessons learned from tests conducted in Mozambique and Zimbabwe

Human-wildlife conflicts (HWCs) have drastically increased around conservation areas in Africa in recent decades, thus undermining the peaceful cohabitation of wildlife populations and rural human settlements. Mitigation packages include HWC reporting, which is often ineffective since the information conveyed is generally scattered and useless. The booming mobile phone sector and the popular use of text messages (SMS) have provided an opportunity to assess the impact of real-time communication systems in HWC mitigation strategies. This paper presents the results of preliminary tests conducted in Mozambique and Zimbabwe with FrontlineSMS, a mobile data collection system. With sets of 52 wildlife playing cards, any wildlife events from patrol reports to HWCs were easily translated into explanatory variables listed on forms. Sending written information as text messages was hampered by IT problems linked with the use of commercial 3G USB modems. The overall system could be improved by using GPRD modems allowing a higher SMS flow and, at the informant level, by introducing ad-hoc SMS models to facilitate data capture on mobile phones. Once adopted, HWC early warning systems could be deployed at low cost. (Résumé d'auteur

Large-scale estimation of forest canopy opening using remote sensing in Central Africa

Human activities in tropical rainforests cause disturbances and degradation by opening up the forest canopy. Capacities for measuring the extent of the damage are essential to the calculation of carbon emissions under REDD+ programmes (Reducing Emissions from Deforestation and Forest Degradation). Remote sensing is a powerful tool to provide this type of information (e.g. on logging, mining or infrastructure projects). Various techniques have been used to identify and quantify canopy opening. A further step is to cross-reference past and present canopy opening in order to document the recovery of ecosystems after logging. The method proposed in this article involves a semi-automatic processing chain adapted for LANDSAT imagery. During post-processing, canopy opening information is extracted by means of specific algorithms. A spatial index, calibrated to a low-resolution radiometer, indicates present and past degrees of opening. This process produces estimations of forest degradation that can describe lowresolution remotely-sensed data (such as MODIS) used in continental mapping. These estimations are then cross-referenced with continental land cover maps to gain insights into present-day forest categories. This tool was developed under the CoForChange project, whose overall objective is to predict changes in forests and in tree species distribution in the Congo Basin as a result of global change, and to develop decision-making tools. The article focuses on a full-scale example in real time, in the rainforest located at the borders of the Central African Republic, the Republic of the Congo and Cameroon, which was analysed on a year-by-year basis with thirty years of LANDSAT image archives. (Résumé d'auteur