Centre de documentation
scientifique

Dépouillements

Integration of Hyperion satellite data and a household social survey to caracterize the causes and consequences of reforestation patterns in the Northern Ecuadorian Amazon / S.J. Walsh 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 725 - 735 Titre : Integration of Hyperion satellite data and a household social survey to caracterize the causes and consequences of reforestation patterns in the Northern Ecuadorian Amazon Type de document : Article/Communication Auteurs : S.J. Walsh, Auteur ; Y. Shao, Auteur ; C.F. Mena, Auteur ; A.L. Mccleary, Auteur Année de publication : 2008 Article en page(s) : pp 725 - 735 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] Amazonie [Termes IGN] analyse en composantes principales [Termes IGN] analyse linéaire des mélanges spectraux [Termes IGN] classification dirigée [Termes IGN] classification non dirigée [Termes IGN] Equateur (état) [Termes IGN] forêt équatoriale [Termes IGN] image EO1-Hyperion [Termes IGN] image hyperspectrale [Termes IGN] image Ikonos [Termes IGN] intégration de données [Termes IGN] occupation du sol Résumé : (Auteur) The integration of Hyperion and Ikonos imagery are used to differentiate the subtle spectral differences of landuse/ land-cover types on household farms in the Northern Ecuadorian Amazon (NEA) with an emphasis on secondary and successional forests. Approaches are examined that include the use of Principal Components Analysis to compress the Hyperion hyperspectral data to its most vital spectral channels; linear mixture modeling to derive subpixel fractions of land-use/land-cover types through the generation of spectral endmembers; and supervised and unsupervised classifications to map forest regrowth, agricultural crops and pasture, and other land-uses on 18 survey farms that are spatially coincident with the imagery. A longitudinal socio-economic and demographic survey (1990 and 1999) is used to characterize household farms; a community survey (2000) is used to assess nearby market towns and service centers; GIS is used to represent the resource endowments of farms and their geographic accessibility. Statistical relationships are examined using Spearman rank correlation coefficients to assess the linkages among a number of selected social, geographical, and biophysical variables and secondary and successional forest on household farms. Relationships suggest the importance of household characteristics, farm resources, and geographic access of secondary forests on surveyed household farms that were previously deforested and converted to agriculture through extensification processes. Results support the integrated use of hyperspectral and hyperspatial data for characterizing forest regrowth on household farms, and the use of multi-dimensional social survey data and GIS to assess plausible causes and consequences of land-use/land-cover dynamics in the NEA. Copyright ASPRS Numéro de notice : A2008-199 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.14358/PERS.74.6.725 En ligne : https://doi.org/10.14358/PERS.74.6.725 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29194 [article]

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]

Characterizing patterns of lands degradation potential and agro-ecological sustainability in Nang Rong, Thailand / W. Welsh 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 765 - 773 Titre : Characterizing patterns of lands degradation potential and agro-ecological sustainability in Nang Rong, Thailand Type de document : Article/Communication Auteurs : W. Welsh, Auteur Année de publication : 2008 Article en page(s) : pp 765 - 773 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] caractérisation [Termes IGN] développement durable [Termes IGN] Eucalyptus (genre) [Termes IGN] image Landsat-MSS [Termes IGN] image Landsat-TM [Termes IGN] plantation forestière [Termes IGN] revêtement [Termes IGN] rizière [Termes IGN] surface cultivée [Termes IGN] Thaïlande Résumé : (Auteur) Soil crop suitability data was used to characterize and evaluate land-use/land-cover (LULC) classifications derived from Landsat TM and MSS imagery for 1997, 1985, and 1972. Landsat spectral classifications were post-processed using GIS data into a time-series of pixels that were identified as having agricultural potential (not including household gardens within settlements), and then compared with soil suitability variables to characterize LULC patterns and assess the likelihood of potential for land degradation within the Nang Rong, Thailand study area. Results of this estimate indicate that for extensive areas of upland cash cropping, particularly in the case of cassava, a significant potential for land degradation and hence agro-ecological unsustainability exists. Lowland rain-fed rice cropping, the most areally extensive and temporally persistent form of agriculture, is revealed to be largely agro-ecologically sustainable. A trend in the Nang Rong region is towards planting fast growing eucalyptus trees, a non-native species known to be damaging to the soil and ecology, as a cash crop in both upland and lowland settings for pulpwood, construction framing, and biofuel feedstock, making future potential land degradation scenarios somewhat different than in the past and ongoing monitoring critical. Copyright ASPRS Numéro de notice : A2008-201 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.74.6.765 En ligne : https://doi.org/10.14358/PERS.74.6.765 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29196 [article]

Changing regimes: forested land cover dynamics in Central Siberia 1974-2001 / K.M. Bergen 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 787 - 798 Titre : Changing regimes: forested land cover dynamics in Central Siberia 1974-2001 Type de document : Article/Communication Auteurs : K.M. Bergen, Auteur ; T. Zhao, Auteur ; V. Kharuk, Auteur ; et al., Auteur Année de publication : 2008 Article en page(s) : pp 787 - 798 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] agriculture [Termes IGN] analyse diachronique [Termes IGN] détection de changement [Termes IGN] feuillu [Termes IGN] forêt [Termes IGN] image Landsat [Termes IGN] occupation du sol [Termes IGN] Pinophyta [Termes IGN] risque naturel [Termes IGN] Russie [Termes IGN] Sibérie [Termes IGN] urbanisation Résumé : (Auteur) The twentieth century saw fundamental shifts in northern Eurasian political and land-management paradigms, in Russia culminating in the political transition of 1991. We used the 1972 to 2001 Landsat archive bracketing this transition to observe change trends in southern central Siberian Russia in primarily forested study sites. Landsat resolved conifer, mixed, deciduous and young forest; cuts, burns, and insect disturbance; and wetland, agriculture, bare, urban, and water land covers. Over 70 percent of forest area in the three study sites was likely disturbed prior to 1974. Conifer forest decreased over the 1974 to 2001 study period, with the greatest decrease 1974 to 1990. Logging activity (primarily in conifers) declined more during the 1991 to 2001 post-Soviet period. The area of Young forest increased more during the 1974 to 1990 time period. Deciduous forest increased over both time periods. Agriculture declined over both time periods contributing to forest regrowth in this region. Copyright ASPRS Numéro de notice : A2008-202 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.14358/PERS.74.6.787 En ligne : https://doi.org/10.14358/PERS.74.6.787 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29197 [article]