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Short-term response of Arctic vegetation NDVI to temperature anomalies / I. Olthof in International Journal of Remote Sensing IJRS, vol 28 n° 21-22 (November 2007)  

Public [article]  inInternational Journal of Remote Sensing IJRS > vol 28 n° 21-22 (November 2007) . - pp 4823 - 4840 Titre : Short-term response of Arctic vegetation NDVI to temperature anomalies Type de document : Article/Communication Auteurs : I. Olthof, Auteur ; R. Latifovic, Auteur Année de publication : 2007 Article en page(s) : pp 4823 - 4840 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image [Termes IGN] anomalie thermique [Termes IGN] Arctique [Termes IGN] Canada [Termes IGN] changement climatique [Termes IGN] détection de changement [Termes IGN] Normalized Difference Vegetation Index [Termes IGN] surveillance de la végétation Résumé : (Auteur) The effects of climate change on northern vegetation productivity need to be fully understood in order to reduce uncertainties in predicting vegetation distributions under different climate warming scenarios. Knowledge of the relationship between northern climate and vegetation productivity will also help provide a better understanding of changes in vegetation distributions as an indicator of climate change and variability. Vegetation productivity and biomass have been monitored using long-term satellite earth observations, mostly using the Normalized Difference Vegetation Index (NDVI), as a cumulative indicator of all effects resulting from processes related to climate change, including changes in temperature, precipitation, and disturbance. In this paper, the investigation is focused on the short-term effect of temperature anomalies on arctic and tree-line transition vegetation productivity in both dry and humid regions of Canada. The analysis shows that several land-cover types composed mainly of trees and shrubs exhibit a significant increase in NDVI with higher-than-normal temperatures in the preceding 10-40-day period, while land-cover types consisting of lichen and moss growing on mostly barren surfaces show a significant NDVI decrease with increased temperature. These trends are consistent with results reported in plot-warming experiments in the north, which have shown that certain vegetation communities increase, while others decrease in cover fraction and biomass in response to warming. When land cover is grouped into increasing and decreasing NDVI with temperature and stratified by dry and humid regions of Canada, much of the dry region of northern Canada does not exhibit significant NDVI response to preceding temperature anomalies. It is expected that in the absence of disturbance or other limiting factors, an increased frequency of elevated temperature anomalies may eventually contribute to changes in vegetation biomass. A map of land-cover types that have the potential to increase in biomass with climate warming and those that are vulnerable to decline is presented. Copyright Taylor & Francis Numéro de notice : A2007-491 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160701268996 En ligne : https://doi.org/10.1080/01431160701268996 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28854 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
080-07121	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Variability of fire-induced changes in MODIS surface reflectance by land-cover type in Borneo / Jukka Miettinen in International Journal of Remote Sensing IJRS, vol 28 n° 21-22 (November 2007)  

Public [article]  inInternational Journal of Remote Sensing IJRS > vol 28 n° 21-22 (November 2007) . - pp 4967 - 4984 Titre : Variability of fire-induced changes in MODIS surface reflectance by land-cover type in Borneo Type de document : Article/Communication Auteurs : Jukka Miettinen, Auteur Année de publication : 2007 Article en page(s) : pp 4967 - 4984 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image [Termes IGN] analyse discriminante [Termes IGN] Bornéo, île de [Termes IGN] couvert végétal [Termes IGN] image Aqua-MODIS [Termes IGN] image Terra-MODIS [Termes IGN] incendie de forêt [Termes IGN] occupation du sol [Termes IGN] réflectance de surface [Termes IGN] réflectance spectrale [Termes IGN] variabilité Résumé : (Auteur) This study investigates fire-induced spectral changes detected by the Moderate Resolution Imaging Spectroradiometer (MODIS) in different land-cover types in Borneo. Linear discriminant analysis is used to determine the most powerful band combinations among the MODIS reflective bands for discrimination between burnt and unburnt areas in each land-cover type. The results show that the nature of fire-induced changes is dependent on pre-fire vegetation characteristics in this region. Bands 1 (0.64 um), 2 (0.86 um), and 7 (2.14 um) are found to be the most sensitive bands in land-cover types dominated by green vegetation, and consequently indices or combinations of indices using these three bands are potentially effective for burnt-area detection in the majority of areas. In land-cover types dominated by dry vegetation and soil, MODIS band 5 (1.24 um) alone showed the greatest statistical separability and could not be significantly improved by any multiband index. Copyright Taylor & Francis Numéro de notice : A2007-492 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160701268962 En ligne : https://doi.org/10.1080/01431160701268962 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28855 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
080-07121	RAB	Revue	Centre de documentation	En réserve L003	Disponible