Data/hora: 20/09/2024 21:18:06

Provedor de dados: 	64	
País: 	Brazil	
Título: 	Object-based change detection using semivariogram indices derived from NDVI images: The environmental disaster in Mariana, Brazil	
Autores: 	Silveira,Eduarda Martiniano de Oliveira; Acerbi Júnior,Fausto Weimar; Mello,José Márcio de; Bueno,Inácio Thomaz.	
Data: 	2017-09-01	
Ano: 	2017	
Palavras-chave: 	Remote sensing; Geostatistics; Feature extraction.	
Resumo: 	ABSTRACT Object-based change detection is a powerful analysis tool for remote sensing data, but few studies consider the potential of temporal semivariogram indices for mapping land-cover changes using object-based approaches. In this study, we explored and evaluated the performance of semivariogram indices calculated from remote sensing imagery, using the Normalized Differential Vegetation Index (NDVI) to detect changes in spatial features related to land cover caused by a disastrous 2015 dam failure in Brazil’s Mariana district. We calculated the NDVI from Landsat 8 images acquired before and after the disaster, then created objects by multiresolution segmentation analysis based on post-disaster images. Experimental semivariograms were computed within the image objects and semivariogram indices were calculated and selected by principal component analysis. We used the selected indices as input data to a support vector machine algorithm for classifying change and no-change classes. The selected semivariogram indices showed their effectiveness as input data for object-based change detection analysis, producing highly accurate maps of areas affected by post-dam-failure flooding in the region. This approach can be used in many other contexts for rapid and accurate assessment of such land-cover changes.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542017000500554	
Editor: 	Editora da Universidade Federal de Lavras	
Relação: 	10.1590/1413-70542017415009817	
Formato: 	text/html	
Fonte: 	Ciência e Agrotecnologia  v.41 n.5 2017	
Fonte: 	info:eu-repo/semantics/openAccess