Centre de documentation
scientifique

Estimating fractional land cover in semi-arid central Kalahari: the impact of mapping method (spectral unmixing vs. object-based image analysis) and vegetation morphology / Niti B. Mishra in Geocarto international, vol 29 n° 7 - 8 (November - December 2014)  

Public [article]  inGeocarto international > vol 29 n° 7 - 8 (November - December 2014) . - pp 860-877 Titre : Estimating fractional land cover in semi-arid central Kalahari: the impact of mapping method (spectral unmixing vs. object-based image analysis) and vegetation morphology Type de document : Article/Communication Auteurs : Niti B. Mishra, Auteur ; K.A. Crews, Auteur Année de publication : 2014 Article en page(s) : pp 860-877 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] analyse de mélange spectral d’extrémités multiples [Termes IGN] classification orientée objet [Termes IGN] image Geoeye [Termes IGN] indice de végétation [Termes IGN] Kalahari, désert du [Termes IGN] occupation du sol [Termes IGN] photosynthèse Résumé : (Auteur) Focusing on the central Kalahari, this study utilized fractional cover of photosynthetic vegetation (fPV), non-photosynthetic vegetation (fNPV) and bare soil (fBS), derived in situ and estimated from GeoEye-1 imagery using Multiple Endmember Spectral Mixture Analysis (MESMA) and object-based image analysis (OBIA) to determine superior method for fractional cover estimation and the impact of vegetation morphology on the estimation accuracy. MESMA mapped fractional cover by testing endmember models of varying complexity. Based on OBIA, image was segmented at five segmentation scales followed by classification. MESMA provided more accurate fractional cover estimates than OBIA. The increasing segmentation scale in OBIA resulted in a consistent increase in error. Different vegetation morphology types showed varied responses to the changing segmentation scale, reflecting their unique ecology and physiognomy. While areas under woody cover produced lower error even at coarse segmentation scales, those with herbaceous cover provided low error only at the fine segmentation scale. Numéro de notice : A2014-470 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106049.2013.868041 En ligne : https://doi.org/10.1080/10106049.2013.868041 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=74047 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
059-2014041	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Disturbance, management, and landscape dynamics: harmonic regression of Vegetation Indices in the Lower Okavango Delta, Botswana / A.L. Neunschwander in Photogrammetric Engineering & Remote Sensing, PERS, vol 74 n° 6 (June 2008)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 74 n° 6 (June 2008) . - pp 753 - 764 Titre : Disturbance, management, and landscape dynamics: harmonic regression of Vegetation Indices in the Lower Okavango Delta, Botswana Type de document : Article/Communication Auteurs : A.L. Neunschwander, Auteur ; K.A. Crews, Auteur Année de publication : 2008 Article en page(s) : pp 753 - 764 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] analyse diachronique [Termes IGN] analyse harmonique [Termes IGN] Botswana [Termes IGN] delta [Termes IGN] image Landsat-ETM+ [Termes IGN] image Landsat-TM [Termes IGN] indice de végétation [Termes IGN] plan d'occupation du sol [Termes IGN] régression [Termes IGN] série temporelle [Termes IGN] surface cultivée [Termes IGN] traitement du signal Résumé : (Auteur) Focused on the Okavango Delta, Botswana, this research investigates (a) whether ecosystem signals derived from remotely sensed imagery can be decomposed using a harmonic regression, (b) if the deviations from the decomposed signal are correlated with observed flooding and fire regimes, and (c) the impact of explicitly including agriculture, settlement areas, and land management systems on the derived signals. A time-series of 85 TM/ETM+ scenes spanning the period from 1989 through 2002 was used to decompose derived landscape dynamics into trends, annual and seasonal cycles, and long term oscillations. The harmonic fit largely defined by climatic periodicities (semi-annual, annual, and quasi-decadal) accounted for 63 percent to 88 percent of the variance in the trajectories. The trends were found to be robust whether or not urban settlement or landscape management regimes were explicitly included, though there was a reversal of trend in agricultural areas. Copyright ASPRS Numéro de notice : A2008-200 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.74.6.753 En ligne : https://doi.org/10.14358/PERS.74.6.753 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29195 [article]