Marc Despinoy | Institut de Recherche pour le Développement (IRD - France) (original) (raw)

Papers by Marc Despinoy

HAL (Le Centre pour la Communication Scientifique Directe), 2016

PLOS Neglected Tropical Diseases, Apr 3, 2017

HAL (Le Centre pour la Communication Scientifique Directe), 2019

HAL (Le Centre pour la Communication Scientifique Directe), Oct 11, 2017

IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477), 2003

This paper illustrates the advantages of the hyperspectral data for sugar cane crop management. I... more This paper illustrates the advantages of the hyperspectral data for sugar cane crop management. In 2002, a CASI airborne campaign and a ground measurement experiment were set up over sugar cane sites in Reunion Island. Early results indicate that LAI and biomass are significantly correlated with some narrow spectral bands in the NIR and that chemical leaf contents are well correlated with the PRI index. A multi-regression procedure was used to calculate transfer functions in order to produces thematic maps of LAI, biomass and nitrogen.

Revue internationale de géomatique, 2005

Les modifications du couvert vegetal et de l'usage de la terre, qui resultent d'amenageme... more Les modifications du couvert vegetal et de l'usage de la terre, qui resultent d'amenagements non raisonnes, sont connus pour etre les principaux facteurs accelerant les processus d'erosion. Ces facteurs sont en constante evolution et leur suivi sur le terrain suppose un dispositif experimental lourd. Cette etude s'est focalisee sur les potentialites des images satellites SPOT 4 et 5, pour extraire les types d'occupation du sol a l'echelle d'un bassin versant de l'ile de La Reunion. L'occupation du sol a ete combinee a d'autres facteurs d'erosion (pente et type de sol) au sein d'un systeme d'information geographique (SIG) et un arbre de decision a ete construit pour elaborer des cartes de sensibilite des sols a l'erosion. Deux cartes ont ete produites pour les annees 1995 et 2002. Ce travail a permis d'isoler les zones de forte sensibilite, de suivre leur evolution dans le temps, mais surtout de souligner l'importance des changements de l'occupation du sol dans cette evolution. (Resume d'auteur)

Remote Sensing, 2022

Tropical cyclones (TCs) can have profound effects on the dynamics of forest vegetation that need ... more Tropical cyclones (TCs) can have profound effects on the dynamics of forest vegetation that need to be better understood. Here, we analysed changes in forest vegetation induced by TCs using the normalized difference vegetation index (NDVI). We used an accurate historical database of TC tracks and intensities, together with the Willoughby cyclone model to reconstruct the 2D surface wind speed structure of TCs and analyse how TCs affect forest vegetation. We used segmented linear models to identify significant breakpoints in the relationship between the reconstructed maximum sustained wind speed (Wmax) and the observed changes in NDVI. We tested the hypothesis that the rate of change in damage caused by TCs to forest and recovery time would increase according to Wmax thresholds as defined in the widely used Saffir–Simpson hurricane wind scale (SSHWS). We showed that the most significant breakpoint was located at 50 m/s. This breakpoint corresponds to the transition between categories ...

Le programme « Fonctionnement des petits bassins versant miniers » a fait l’objet d’une restituti... more Le programme « Fonctionnement des petits bassins versant miniers » a fait l’objet d’une restitution publique le 2 Decembre 2014. Parallelement a cette restitution, un rapport scientifique a ete produit, regroupant l’ensemble des contributions des differents partenaires du consortium scientifique. Le lecteur de la presente synthese pourra utilement s’y referer pour obtenir les elements d’information dont il pourrait avoir besoin pour completer ceux qui vont etre presentes dans ce rapport, sous un format volontairement reduit. L’objectif du present document est de presenter a l’attention prioritaire de la profession et des services techniques des collectivites, les resultats essentiels que l’on peut degager des efforts de recherche realises dans le cadre du programme, les avancees obtenues, mais aussi les difficultes rencontrees et les actions restant a produire pour conforter les acquis du programme. Le formalisme propre aux publications scientifiques sera donc volontairement reduit ...

Plos neglected tropical diseases, 2017

Background Dengue is a mosquito-borne virus that causes extensive morbidity and economic loss in ... more Background Dengue is a mosquito-borne virus that causes extensive morbidity and economic loss in many tropical and subtropical regions of the world. Often present in cities, dengue virus is rapidly spreading due to urbanization, climate change and increased human movements. Dengue cases are often heterogeneously distributed throughout cities, suggesting that small-scale determinants influence dengue urban transmission. A better understanding of these determinants is crucial to efficiently target prevention measures such as vector control and education. The aim of this study was to determine which socioeconomic and environmental determinants were associated with dengue incidence in an urban setting in the Pacific. Methodology An ecological study was performed using data summarized by neighborhood (i.e. the neighborhood is the unit of analysis) from the last two dengue epidemics (2008–2009 and 2012–2013) in the city of Nouméa, the capital of New Caledonia. Spatial patterns and hotspot...

CIRAD, HJRBDA and NAERLS undertook a collaborative programme on the Hadejia Valley Irrigation Pro... more CIRAD, HJRBDA and NAERLS undertook a collaborative programme on the Hadejia Valley Irrigation Project to strengthen the agency and the Water Users Associations (WUAs) in their roles and to ensure an efficient transfer of responsibilities from the agency to the farmers. In the scope of the implementation of the Agency/fanner Joint Management concept, stakeholders decided to develop an information system able to provide information for the assessment of the system. The tool aimed to promote the discussion and negotiation between project managers and WUA leaders. The tool is composed of a relational database and a Geographical Information System (GIS). Technically four databases were created to get faster response time. Data entry, storage and analysis are done from a user-friendly interface. Making queries using Mapinfo software automatically generates tables and charts about the irrigation scheme performances. The GIS stores the spatial (Geographical) data. It enables users to repres...

Remote. Sens., 2021

Land use (LU) and land cover (LC) are two complementary pieces of cartographic information used f... more Land use (LU) and land cover (LC) are two complementary pieces of cartographic information used for urban planning and environmental monitoring. In the context of New Caledonia, a biodiversity hotspot, the availability of up-to-date LULC maps is essential to monitor the impact of extreme events such as cyclones and human activities on the environment. With the democratization of satellite data and the development of high-performance deep learning techniques, it is possible to create these data automatically. This work aims at determining the best current deep learning configuration (pixel-wise vs. semantic labelling architectures, data augmentation, image prepossessing, . . . ), to perform LULC mapping in a complex, subtropical environment. For this purpose, a specific data set based on SPOT6 satellite data was created and made available for the scientific community as an LULC benchmark in a tropical, complex environment using five representative areas of New Caledonia labelled by a...