Retrieval of Vegetation Indices Related to Leaf Water Content from a Single Index: A Case Study of Eucalyptus globulus (Labill.) and Pinus radiata (D. Don.)

Abstract

The vegetation indices derived from spectral reflectance have served as an indicator of vegetation’s biophysical and biochemical parameters. Some of these indices are capable of characterizing more than one parameter at a time. This study examines the feasibility of retrieving several spectral vegetation indices from a single index under the assumption that all these indices are correlated with water content. The models used are based on a linear regression adjusted with least squares. The spectral signatures of Eucalyptus globulus and Pinus radiata, which constitute 97.5% of the forest plantation in Valparaiso region in Chile, have been used to test and validate the proposed approach. The linear models were fitted with an independent data set from which their performance was assessed. The results suggest that from the Leaf Water Index, other spectral indices can be recovered with a root mean square error up to 0.02, a bias of 1.12%, and a coefficient of determination of 0.77. The latter encourages using a sensor with discrete wavelengths instead of a continuum spectrum to estimate the forestry’s essential parameters.

Spatial-Temporal Characteristics and Driving Forces of Aboveground Biomass in Desert Steppes of Inner Mongolia, China in the Past 20 Years

“…Feature selection is a critical step in remote-sensing-based AGB monitoring [10]. Currently, the main variables used to retrieve vegetation AGB are derived from spectral reflectance and vegetation indices (VI) [11,12]. As VIs are calculated based on the reflectance of multiple spectral bands, they exhibit high sensitivity to surface features, including vegetation, making them the preferred variables for biomass observation [13].…”

Desenvolvimento de ferramentas de geotecnologias para análise da qualidade da lavoura e estimativa da taxa de germinação aplicadas à cultura da soja

“…DI LORENZO et al (2021), ao estudar assinaturas espectrais de vinhedos tanto por equipamento de contato quanto por imagem orbitais conseguiram distinguir diferentes cultivares para uva de mesa, além disso, conseguiram distinguir diferentes práticas de gestão entre plantações de mesma cultivar. VILLACRÉS et al (2021) desenvolveram um índice de vegetação através das assinaturas espectrais para analisar conteúdo de água na folha de eucaliptos e pinus, os resultados sugerem que, a partir do índice criado para água na folha outros índices espectrais podem ser recuperados com um rmse de até 0,02 e um r 2 de 0,77. E NETO et al (2019), ao analisar assinaturas espectrais de cafezal ao longo dos anos conseguiu distinguir entre os anos qual foi o ano com maior produtividade no local, além disso, descreveu possíveis mecanismos fenológicos predominantes em cada ano que resultaram nas produtividades através da assinatura espectral.…”