Data/hora: 21/06/2024 13:14:41

Biblioteca(s): | Embrapa Solos.
Data corrente: | 21/10/2016
Data da última atualização: | 07/11/2016
Autoria: | PESSOA, L. G. M.; FREIRE, M. B. G. dos S.; WILCOX, B. P.; GREEN, C. H. M.; ARAÚJO, R. J. T. de; ARAUJO FILHO, J. C. de.
Afiliação: | LUIZ GUILHERME MEDEIROS PESSOA, UFRPE; MARIA BETÂNIA GALVÃO DOS SANTOS FREIRE, UFRPE; BRADFORD PAUL WILCOX, Texas A&M University; COLLEEN HEATHER MACHADO GREEN, U. S. Department of the Interior, Bureau of Land Management, National Operations Center; RÔMULO JOSÉ TOLÊDO DE ARAÚJO, UFRPE; JOSE COELHO DE ARAUJO FILHO, CNPS.
Título: | Spectral reflectance characteristics of soils in northeastern Brazil as influenced by salinity levels.
Ano de publicação: | 2016
Fonte/Imprenta: | Environmental Monitoring and Assessment, v. 188, n. 11, Nov. 2016.
DOI: | 10.1007/s10661-016-5631-6
Idioma: | Inglês
Conteúdo: | In northeastern Brazil, large swaths of onceproductive soils have been severely degraded by soil salinization, but the true extent of the damage has not been assessed. Emerging remote sensing technology based on hyperspectral analysis offers one possibility for large-scale assessment, but it has been unclear to what extent the spectral properties of soils are related to salinity characteristics. The purpose of this study was to characterize the spectral properties of degraded (saline) and non-degraded agricultural soils in northeastern Brazil and determine the extent to which these properties correspond to soil salinity. We took soil samples from 78 locations within a 45,000-km2 site in Pernambuco State. We used cluster analysis to group the soil samples on the basis of similarities in salinity and sodicity levels, and then obtained spectral data for each group. The physical properties analysis indicated a predominance of the coarse sand fraction in almost all the soil groups, and total porosity was similar for all the groups. The chemical analysis revealed different levels of degradation among the groups, ranging from nondegraded to strongly degraded conditions, as defined by the degree of salinity and sodicity. The soil properties showing the highest correlation with spectral reflectance were the exchangeable sodium percentage followed by fine sand. Differences in the reflectance curves for the various soil groups were relatively small and were not significant. These results suggest that, where soil crusts are not present, significant challenges remain for using hyperspectral remote sensing to assess soil salinity in northeastern Brazil.
Palavras-Chave: | Monitoramento da salinidade; Salinidade do solo; Semiárido; Sodicidade do solo.
Categoria do assunto: | P Recursos Naturais, Ciências Ambientais e da Terra
Registro original: | Embrapa Solos (CNPS)
Exemplares: | CNPS - (19375-1) - UPC - AP - DD -  -  - 2016.00268 - DIS