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Mapping vegetation in a heterogeneous mountain rangeland using Landsat data: an alternative method to define and classify land-cover units / A.M. Cingolani in Remote sensing of environment, vol 92 n° 1 (15 July 2004)  

Public [article]  inRemote sensing of environment > vol 92 n° 1 (15 July 2004) . - pp 84 - 97 Titre : Mapping vegetation in a heterogeneous mountain rangeland using Landsat data: an alternative method to define and classify land-cover units Type de document : Article/Communication Auteurs : A.M. Cingolani, Auteur ; D. Renison, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 84 - 97 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] analyse comparative [Termes IGN] analyse discriminante [Termes IGN] Argentine [Termes IGN] bande spectrale [Termes IGN] carte de la végétation [Termes IGN] classification dirigée [Termes IGN] classification par maximum de vraisemblance [Termes IGN] données de terrain [Termes IGN] état de conservation [Termes IGN] flore locale [Termes IGN] image Landsat [Termes IGN] limite de résolution géométrique [Termes IGN] montagne [Termes IGN] occupation du sol [Termes IGN] photo-interprétation assistée par ordinateur Résumé : (Auteur) Three major problems are faced when mapping natural vegetation with mid-resolution satellite images using conventional supervised classification techniques: defining the adequate hierarchical level for mapping; defining discrete land cover units discernible by the satellite; and selecting representative training sites. In order to solve these problems, we developed an approach based on the: (1) definition of ecologically meaningful units as mosaics or repetitive combinations of structural types, (2) utilization of spectral information (indirectly) to define the units, (3) exploration of two alternative methods to classify the units once they are defined: the traditional, Maximum Likelihood method, which was enhanced by analyzing objective ways of selecting the best training sites, and an alternative method using Discriminant Functions directly obtained from the statistical analysis of signatures. The study was carried out in a heterogeneous mountain rangeland in central Argentina using Landsat data and 251 field sampling sites. On the basis of our analysis combining terrain information (a matrix of 251 stands X 14 land cover attributes) and satellite data (a matrix of 251 stands x 8 bands), we defined 8 land cover units (mosaics of structural types) for mapping, emphasizing the structural types which had stronger effects on reflectance. The comparison through field validation of both methods for mapping units showed that classification based on Discriminant Functions produced better results than the traditional Maximum Likelihood method (accuracy of 86% vs. 78%). Numéro de notice : A2004-300 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2004.05.008 En ligne : https://doi.org/10.1016/j.rse.2004.05.008 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26827 [article]