Kalideos OSR MIPY : un observatoire pour la recherche et la démonstration des applications de la télédétection à la gestion des territoires., 2012
Abstract
For the last 10 years, CESBIO has been building a Regional Spatial Observatory (OSR), d... more Abstract
For the last 10 years, CESBIO has been building a Regional Spatial Observatory (OSR), dedicated to coupled terrain and space observations, in the South-West of France. The OSR relies on monthly acquisition of optical images with a 10 meter resolution, started in 2002, and on heavy instrumented sites layed out since 2004 (permanent measurements of water and carbon fluxes). This system was labeled “observation service” by CNRS/INSU in 2007, and became a CNES KALIDEOS site by the end of 2009. The core site has the extent of a SPOT image (50*50km) and spans over very
diverse landscapes, with large variations in pedology and topography and diverse land covers, land uses, agricultural practices and climates (with a strong gradient in summer water stress).
Regarding remote sensing, this site has served the preparation of SMOS, and it is now mainly used to anticipate the launch of VENμS and Sentinel-2 satellite missions. Radar and thermal image use is growing and combined approaches are being developed. The research focuses on image quality enhancement, quantitative measurements and signal processing. Regarding thematic research, CESBIO focuses on cereal and oleaginous crops modeling and monitoring.
The involvement of new scientific partners and of local managers prompted the development of new studies such as biodiversity, land management, and urban extension monitoring, environmental risks, forest health, grassland diversity
and productivity. CESBIO and partners are also starting new studies to make the most of a 10 years archive of data: this archive seems really relevant to study the impact of the atypical climates observed in 2003 and 2011. Finally, the extrapolation to the whole region Midi-Pyrénées or to the whole Pyrenees Mountains has started.
Keywords: observatory, long-term, modelling, land cover, validation, time series.
Le Centre pour la Communication Scientifique Directe - HAL - Grenoble Ecole de Management, 2012
Ces dernières années, le CESBIO a mis en place un Observatoire Spatial Régional 'OSR' : un dispos... more Ces dernières années, le CESBIO a mis en place un Observatoire Spatial Régional 'OSR' : un dispositif d'observation couplant mesures de terrain et télédétection dans le sud-ouest de la France. L'OSR se base sur des acquisitions mensuelles de données satellitaires à résolution décamétrique depuis 2002 et sur des sites expérimentaux lourdement instrumentés (mesures en continu de flux d'eau et de carbone) à partir de 2004. Ce dispositif a été reconnu service d'observation par l'INSU/CNRS en 2007 et site KALIDEOS par le CNES fin 2009 : 'KALIDEOS OSR MiPy'. Le site atelier correspond à une emprise d'image SPOT, soit environ 50x50 km et couvre une grande diversité de milieux (pédologie, topographie), d'occupation et d'utilisation des sols, de pratiques et de modalités de gestion (agricole, forestière…) et de conditions climatiques (fort gradient de déficits hydriques estivaux). Pour la télédétection, ce site a servi la préparation de SMOS, et il soutient maintenant en priorité à la préparation des missions VENµS et Sentinel-2. Les aspects radar, imagerie thermique et les approches multi-capteurs se développent depuis peu. Le traitement du signal, la physique de la mesure et l'amélioration de la qualité des données constituent le premier axe de recherche. Au niveau thématique, le CESBIO a pour priorité les suivis et les modélisations des agrosystèmes de grandes cultures. L'implication récente d'autres partenaires scientifiques ou gestionnaires a permis d'initier des travaux sur d'autres aspects, comme la biodiversité, l'aménagement du territoire, le suivi de l'extension urbaine, les risques environnementaux, la santé des forêts, l'enfrichement, la diversité et la productivité des prairies. La valorisation des 10 années d'archives 2002-2011 débute et semble très pertinente pour la caractérisation en haute et en basse résolution des conséquences d'années climatiques atypiques (2003, 2011) sur les éco-agro-systèmes. L'extrapolation des résultats obtenus sur ce site atelier à toute la région Midi-Pyrénées ou à la chaine des Pyrénées est aussi initiée.
Poster préparé en s'appuyant sur les conclusions du Groupe de Travail Interorganismes animé par l... more Poster préparé en s'appuyant sur les conclusions du Groupe de Travail Interorganismes animé par le CNES et chargé de la définition technique du Pôle, composé de : S. Cherchali (CNES Toulouse), P. Kosuth (Tetis / IRSTEA Montpellier), A. Bégué (Tetis / CIRAD Montpellier), F.M. Bréon (LSCE / CEA Saclay),
Cette étude a été conduite pour comprendre le mécanisme de la production primaire des savanes d'A... more Cette étude a été conduite pour comprendre le mécanisme de la production primaire des savanes d'AMque occidentale en utilisant les dOMéeS a haute résolution SPOT XS et LANDSAT TM combinées ä des mesures de terrain. Le suivi des courbes dévolution du NDVI mesuré au sol fournit l'amplitude et la durée du cycle de la biomasse herbacée. Les relations calculées entre, le NDVI et la biomasse fraïche mesurés au sol d'une part, les réflectances dans le MIR et le rapport poids sec/poids frais de biomasse d'autre part, montrent qu'il est possible de suivre l'évolution des biomasses totale et sèche durant un cycle de production. L'évolution du NDVI calculé sur les données TM permet de décrire quantitativement et en terme de surface le recouvrement de la végétation. En combinant ì'évolution des réflectances TM5 et du NDVI on peut discriminer les différents types de végétation. L'hétérogénéité dans la distribution de la couverture végétale des savanes et des steppes est décrite au moyen de parametres statistiques.
During a field campaign of the Savannas on the Long Term (SALT) Global Change and Terrestrial Eco... more During a field campaign of the Savannas on the Long Term (SALT) Global Change and Terrestrial Ecosystems/International Geosphere Biosphere Program dealing with the energy budget of a West African moist savanna, particular attention was paid to the radiation .budget because it is the driving force. for all other surface fluxes; AU components ,of the radiation budget. were measured on. the ground during one and'a half year on a test site 'in Ivory Coast. The seasonal variations of the observed radiation at the surface and satellite data were compared to .the values simulated' for. the 1978-1988 period by a general circulation model coupled to a land surface parameterization scheme, both developed by the Laboratoire de Météorologie Dynamique (LMD). Problems which appear when point observations of surface fluxes are ,compared with results from general circulation model simulations are addressed. Seasonal variations of the ,prescribed savanna albedo in the model differed sigliificantly from the observed variations due to .bush fire influence. However, the major discrepancy between model simulations and surface observations resulted from the overestimation of the inconhing shortwave radiation at'the surface. The major sources of discrepancy were found to be the simulated clear-sky atmospheric absorption and/or scattering of the shortwave radiation and the simulation of cloud and/or cloud-radiation interactions which lead to an overestimation of 'the absorbed energy at the surface by the model. It is concluded that improvement of the simulated energy budget in the humid tropics depends critically on a good simulation of the incoming shortwave radiation at the surface.
Gaseous nitrogen compounds (NO~, NOy, NH3, N20) were measured at ground level in smoke plumes of ... more Gaseous nitrogen compounds (NO~, NOy, NH3, N20) were measured at ground level in smoke plumes of prescribed savanna fires in Lamto, in the southern Ivory Coast, during the FOS/DECAFE experiment in January 1991. During the flaming phase, the linear regression between 6[NO~ ] and 6[COz] (differences in concentration between smoke plumes and atmosheric background) results volumic emission ratio 6~O~]/~[CO2] = 1.37 × 10-3 with only slight differences between heading and backing fires. Nearly 90% of the nitrogen oxides are emitted as NO. Average emission ratios of other compounds are: 1.91, 0.047, and 0.145 x 10-3 for NO~, NH3 and N20, respectively. The emission ratios obtained during this field experiment are compred with corresponding values measured during former experiments with the same plant species in combustion chambers. An accurate determination of both the biomass actually burned and of the plant nitrogen content, allows an assessment of emission fluxes of N-compounds from Guinean savanna burns. Preliminary results dealing with the influence of fire on biogenic emissions from soils are also reported.
Prédire la nature et l'intensité des modifications du fonctionnement et de la dynamique des s... more Prédire la nature et l'intensité des modifications du fonctionnement et de la dynamique des savanes sous l'effet des pressions climatiques et humaines, présentes et à venir. Ce qui implique : d'identifier et d'analyser la réponse des écosystèmes aux pressions naturelles et anthropiques ; d'étudier les échanges savanes-atmosphère (effets rétroactifs) ; . de spatialiser les processus aux échelles régionale et continentale.
Analyse de la dynamique des savanes d'Afrique de l'Ouest: mécanismes sous-jacents et spatialisati... more Analyse de la dynamique des savanes d'Afrique de l'Ouest: mécanismes sous-jacents et spatialisation des processus
... Evolution sur 20 ans d'une parcelle de savane boisée non protégée du feu dans la réserve... more ... Evolution sur 20 ans d'une parcelle de savane boisée non protégée du feu dans la réserve de Lamto (Côte-d'Ivoire) = Twenty years' evolution of a woody savanna not protected from fire situated in the Lamto Reserve (Ivory Coast). Auteur(s) / Author(s). ... Feu végétation. ; ...
Global approaches taking into account the human activities, the physical biological and chemical ... more Global approaches taking into account the human activities, the physical biological and chemical processes, and the conflicts of interest, lay out new and complex questions for the territorial managers and the decision makers. This is particularly critical for areas going from the field to the landscape scale. Decision-making tools for territorial management integrating complex specialised models are necessary to carry
Kalideos OSR MIPY : un observatoire pour la recherche et la démonstration des applications de la télédétection à la gestion des territoires., 2012
Abstract
For the last 10 years, CESBIO has been building a Regional Spatial Observatory (OSR), d... more Abstract
For the last 10 years, CESBIO has been building a Regional Spatial Observatory (OSR), dedicated to coupled terrain and space observations, in the South-West of France. The OSR relies on monthly acquisition of optical images with a 10 meter resolution, started in 2002, and on heavy instrumented sites layed out since 2004 (permanent measurements of water and carbon fluxes). This system was labeled “observation service” by CNRS/INSU in 2007, and became a CNES KALIDEOS site by the end of 2009. The core site has the extent of a SPOT image (50*50km) and spans over very
diverse landscapes, with large variations in pedology and topography and diverse land covers, land uses, agricultural practices and climates (with a strong gradient in summer water stress).
Regarding remote sensing, this site has served the preparation of SMOS, and it is now mainly used to anticipate the launch of VENμS and Sentinel-2 satellite missions. Radar and thermal image use is growing and combined approaches are being developed. The research focuses on image quality enhancement, quantitative measurements and signal processing. Regarding thematic research, CESBIO focuses on cereal and oleaginous crops modeling and monitoring.
The involvement of new scientific partners and of local managers prompted the development of new studies such as biodiversity, land management, and urban extension monitoring, environmental risks, forest health, grassland diversity
and productivity. CESBIO and partners are also starting new studies to make the most of a 10 years archive of data: this archive seems really relevant to study the impact of the atypical climates observed in 2003 and 2011. Finally, the extrapolation to the whole region Midi-Pyrénées or to the whole Pyrenees Mountains has started.
Keywords: observatory, long-term, modelling, land cover, validation, time series.
Le Centre pour la Communication Scientifique Directe - HAL - Grenoble Ecole de Management, 2012
Ces dernières années, le CESBIO a mis en place un Observatoire Spatial Régional 'OSR' : un dispos... more Ces dernières années, le CESBIO a mis en place un Observatoire Spatial Régional 'OSR' : un dispositif d'observation couplant mesures de terrain et télédétection dans le sud-ouest de la France. L'OSR se base sur des acquisitions mensuelles de données satellitaires à résolution décamétrique depuis 2002 et sur des sites expérimentaux lourdement instrumentés (mesures en continu de flux d'eau et de carbone) à partir de 2004. Ce dispositif a été reconnu service d'observation par l'INSU/CNRS en 2007 et site KALIDEOS par le CNES fin 2009 : 'KALIDEOS OSR MiPy'. Le site atelier correspond à une emprise d'image SPOT, soit environ 50x50 km et couvre une grande diversité de milieux (pédologie, topographie), d'occupation et d'utilisation des sols, de pratiques et de modalités de gestion (agricole, forestière…) et de conditions climatiques (fort gradient de déficits hydriques estivaux). Pour la télédétection, ce site a servi la préparation de SMOS, et il soutient maintenant en priorité à la préparation des missions VENµS et Sentinel-2. Les aspects radar, imagerie thermique et les approches multi-capteurs se développent depuis peu. Le traitement du signal, la physique de la mesure et l'amélioration de la qualité des données constituent le premier axe de recherche. Au niveau thématique, le CESBIO a pour priorité les suivis et les modélisations des agrosystèmes de grandes cultures. L'implication récente d'autres partenaires scientifiques ou gestionnaires a permis d'initier des travaux sur d'autres aspects, comme la biodiversité, l'aménagement du territoire, le suivi de l'extension urbaine, les risques environnementaux, la santé des forêts, l'enfrichement, la diversité et la productivité des prairies. La valorisation des 10 années d'archives 2002-2011 débute et semble très pertinente pour la caractérisation en haute et en basse résolution des conséquences d'années climatiques atypiques (2003, 2011) sur les éco-agro-systèmes. L'extrapolation des résultats obtenus sur ce site atelier à toute la région Midi-Pyrénées ou à la chaine des Pyrénées est aussi initiée.
Poster préparé en s'appuyant sur les conclusions du Groupe de Travail Interorganismes animé par l... more Poster préparé en s'appuyant sur les conclusions du Groupe de Travail Interorganismes animé par le CNES et chargé de la définition technique du Pôle, composé de : S. Cherchali (CNES Toulouse), P. Kosuth (Tetis / IRSTEA Montpellier), A. Bégué (Tetis / CIRAD Montpellier), F.M. Bréon (LSCE / CEA Saclay),
Cette étude a été conduite pour comprendre le mécanisme de la production primaire des savanes d'A... more Cette étude a été conduite pour comprendre le mécanisme de la production primaire des savanes d'AMque occidentale en utilisant les dOMéeS a haute résolution SPOT XS et LANDSAT TM combinées ä des mesures de terrain. Le suivi des courbes dévolution du NDVI mesuré au sol fournit l'amplitude et la durée du cycle de la biomasse herbacée. Les relations calculées entre, le NDVI et la biomasse fraïche mesurés au sol d'une part, les réflectances dans le MIR et le rapport poids sec/poids frais de biomasse d'autre part, montrent qu'il est possible de suivre l'évolution des biomasses totale et sèche durant un cycle de production. L'évolution du NDVI calculé sur les données TM permet de décrire quantitativement et en terme de surface le recouvrement de la végétation. En combinant ì'évolution des réflectances TM5 et du NDVI on peut discriminer les différents types de végétation. L'hétérogénéité dans la distribution de la couverture végétale des savanes et des steppes est décrite au moyen de parametres statistiques.
During a field campaign of the Savannas on the Long Term (SALT) Global Change and Terrestrial Eco... more During a field campaign of the Savannas on the Long Term (SALT) Global Change and Terrestrial Ecosystems/International Geosphere Biosphere Program dealing with the energy budget of a West African moist savanna, particular attention was paid to the radiation .budget because it is the driving force. for all other surface fluxes; AU components ,of the radiation budget. were measured on. the ground during one and'a half year on a test site 'in Ivory Coast. The seasonal variations of the observed radiation at the surface and satellite data were compared to .the values simulated' for. the 1978-1988 period by a general circulation model coupled to a land surface parameterization scheme, both developed by the Laboratoire de Météorologie Dynamique (LMD). Problems which appear when point observations of surface fluxes are ,compared with results from general circulation model simulations are addressed. Seasonal variations of the ,prescribed savanna albedo in the model differed sigliificantly from the observed variations due to .bush fire influence. However, the major discrepancy between model simulations and surface observations resulted from the overestimation of the inconhing shortwave radiation at'the surface. The major sources of discrepancy were found to be the simulated clear-sky atmospheric absorption and/or scattering of the shortwave radiation and the simulation of cloud and/or cloud-radiation interactions which lead to an overestimation of 'the absorbed energy at the surface by the model. It is concluded that improvement of the simulated energy budget in the humid tropics depends critically on a good simulation of the incoming shortwave radiation at the surface.
Gaseous nitrogen compounds (NO~, NOy, NH3, N20) were measured at ground level in smoke plumes of ... more Gaseous nitrogen compounds (NO~, NOy, NH3, N20) were measured at ground level in smoke plumes of prescribed savanna fires in Lamto, in the southern Ivory Coast, during the FOS/DECAFE experiment in January 1991. During the flaming phase, the linear regression between 6[NO~ ] and 6[COz] (differences in concentration between smoke plumes and atmosheric background) results volumic emission ratio 6~O~]/~[CO2] = 1.37 × 10-3 with only slight differences between heading and backing fires. Nearly 90% of the nitrogen oxides are emitted as NO. Average emission ratios of other compounds are: 1.91, 0.047, and 0.145 x 10-3 for NO~, NH3 and N20, respectively. The emission ratios obtained during this field experiment are compred with corresponding values measured during former experiments with the same plant species in combustion chambers. An accurate determination of both the biomass actually burned and of the plant nitrogen content, allows an assessment of emission fluxes of N-compounds from Guinean savanna burns. Preliminary results dealing with the influence of fire on biogenic emissions from soils are also reported.
Prédire la nature et l'intensité des modifications du fonctionnement et de la dynamique des s... more Prédire la nature et l'intensité des modifications du fonctionnement et de la dynamique des savanes sous l'effet des pressions climatiques et humaines, présentes et à venir. Ce qui implique : d'identifier et d'analyser la réponse des écosystèmes aux pressions naturelles et anthropiques ; d'étudier les échanges savanes-atmosphère (effets rétroactifs) ; . de spatialiser les processus aux échelles régionale et continentale.
Analyse de la dynamique des savanes d'Afrique de l'Ouest: mécanismes sous-jacents et spatialisati... more Analyse de la dynamique des savanes d'Afrique de l'Ouest: mécanismes sous-jacents et spatialisation des processus
... Evolution sur 20 ans d'une parcelle de savane boisée non protégée du feu dans la réserve... more ... Evolution sur 20 ans d'une parcelle de savane boisée non protégée du feu dans la réserve de Lamto (Côte-d'Ivoire) = Twenty years' evolution of a woody savanna not protected from fire situated in the Lamto Reserve (Ivory Coast). Auteur(s) / Author(s). ... Feu végétation. ; ...
Global approaches taking into account the human activities, the physical biological and chemical ... more Global approaches taking into account the human activities, the physical biological and chemical processes, and the conflicts of interest, lay out new and complex questions for the territorial managers and the decision makers. This is particularly critical for areas going from the field to the landscape scale. Decision-making tools for territorial management integrating complex specialised models are necessary to carry
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Papers by J. Menaut
For the last 10 years, CESBIO has been building a Regional Spatial Observatory (OSR), dedicated to coupled terrain and space observations, in the South-West of France. The OSR relies on monthly acquisition of optical images with a 10 meter resolution, started in 2002, and on heavy instrumented sites layed out since 2004 (permanent measurements of water and carbon fluxes). This system was labeled “observation service” by CNRS/INSU in 2007, and became a CNES KALIDEOS site by the end of 2009. The core site has the extent of a SPOT image (50*50km) and spans over very
diverse landscapes, with large variations in pedology and topography and diverse land covers, land uses, agricultural practices and climates (with a strong gradient in summer water stress).
Regarding remote sensing, this site has served the preparation of SMOS, and it is now mainly used to anticipate the launch of VENμS and Sentinel-2 satellite missions. Radar and thermal image use is growing and combined approaches are being developed. The research focuses on image quality enhancement, quantitative measurements and signal processing. Regarding thematic research, CESBIO focuses on cereal and oleaginous crops modeling and monitoring.
The involvement of new scientific partners and of local managers prompted the development of new studies such as biodiversity, land management, and urban extension monitoring, environmental risks, forest health, grassland diversity
and productivity. CESBIO and partners are also starting new studies to make the most of a 10 years archive of data: this archive seems really relevant to study the impact of the atypical climates observed in 2003 and 2011. Finally, the extrapolation to the whole region Midi-Pyrénées or to the whole Pyrenees Mountains has started.
Keywords: observatory, long-term, modelling, land cover, validation, time series.
For the last 10 years, CESBIO has been building a Regional Spatial Observatory (OSR), dedicated to coupled terrain and space observations, in the South-West of France. The OSR relies on monthly acquisition of optical images with a 10 meter resolution, started in 2002, and on heavy instrumented sites layed out since 2004 (permanent measurements of water and carbon fluxes). This system was labeled “observation service” by CNRS/INSU in 2007, and became a CNES KALIDEOS site by the end of 2009. The core site has the extent of a SPOT image (50*50km) and spans over very
diverse landscapes, with large variations in pedology and topography and diverse land covers, land uses, agricultural practices and climates (with a strong gradient in summer water stress).
Regarding remote sensing, this site has served the preparation of SMOS, and it is now mainly used to anticipate the launch of VENμS and Sentinel-2 satellite missions. Radar and thermal image use is growing and combined approaches are being developed. The research focuses on image quality enhancement, quantitative measurements and signal processing. Regarding thematic research, CESBIO focuses on cereal and oleaginous crops modeling and monitoring.
The involvement of new scientific partners and of local managers prompted the development of new studies such as biodiversity, land management, and urban extension monitoring, environmental risks, forest health, grassland diversity
and productivity. CESBIO and partners are also starting new studies to make the most of a 10 years archive of data: this archive seems really relevant to study the impact of the atypical climates observed in 2003 and 2011. Finally, the extrapolation to the whole region Midi-Pyrénées or to the whole Pyrenees Mountains has started.
Keywords: observatory, long-term, modelling, land cover, validation, time series.