De Noni Georges, Viennot Marc. (1997). Evaluation spatiale et multi-temporelle de la cangahua à partir d'images SPOT. In :
Zebrowski Claude (ed.), Quantin Paul (ed.), Trujillo G. (ed.), Villamar M.D. (collab.). Suelos volcanicos endurecidos. Quito (ECU) ; Quito (ECU) ; Quito (ECU) ; Quito : UE ; ORSTOM ; PUCE ; UCE, p. 138-148. Suelos Volcanicos Endurecidos, 3., Quito (ECU), 1996/12/9-14.
Titre du document
Evaluation spatiale et multi-temporelle de la cangahua à partir d'images SPOT
Année de publication
1997
Type de document
Colloque
Auteurs
De Noni Georges, Viennot Marc
In
Zebrowski Claude (ed.), Quantin Paul (ed.), Trujillo G. (ed.), Villamar M.D. (collab.) Suelos volcanicos endurecidos
Source
Quito (ECU) ; Quito (ECU) ; Quito (ECU) ; Quito : UE ; ORSTOM ; PUCE ; UCE, 1997,
p. 138-148
Colloque
Suelos Volcanicos Endurecidos, 3., Quito (ECU), 1996/12/9-14
The cangahua, important component of the Ecuadorian highlands landscape presents a very weak fertility. This is the result of old-fashioned and inadequate management by the indigenous populations, whose food needs exceed agricultural supplies. It was interesting to evaluate a dynamic process such as the extension of the cangahua with remote sensing from images SPOT as the cangahua mineral material presented a typic spectral response in the 3 main hands. Two experiences are presented: the first dealt with a spatialization of the cangahua on two 10-years periods (1986-1995), on the slopes of the volcano Ilalo, close to Quito, in awell-known and small region (15 sq km). The second compared a conventional field mapping to a satellite mapping of the whole new volcwnic highlands (5 scenes of 60 sq km). The method leant on the definition of themes, the identification of these on well-known areas (trainig samples), the definition of spectral characteristics of the training samples and the extrapolation to the wholw region (classification) in order to minimize geometrical distortions, angular incidence and atmospheric conditions. The first study emphasized the increase of cangahua areas in relation with the settlement, the travelling of men and cattle; the theme of discontinous cangahua with a broad spectral signature expalined a process still dynamic nowadays. The comparison of the 2 mappings showed a convergence for the typic cangahua but the results differed for the disconrinuous one. Remopte-sensing is an efficient tool for mapping cangahua. However it requieres a good knowledge of the field and improvement and automation of the various distorsions. (Résumé d'auteur).
Plan de classement
Pédologie [126TELAPP03]
Descripteurs
CARTE PEDOLOGIQUE ; VARIATION SPATIALE ; VARIATION TEMPORELLE ; IMAGE SATELLITE ; TELEDETECTION SPATIALE ; SATELLITE SPOT ; CLASSIFICATION DIRIGEE ; METHODOLOGIE ; EROSION ; CANGAHUA
Description Géographique
EQUATEUR ; ANDES
Localisation
Fonds IRD [F A010012910] ;
Montpellier (Centre IRD)
;
Quito
Identifiant IRD
fdi:010012919
