Effect of dust deposition on spectrum-based estimation of leaf water content in urban plant. (September 2019)

• Record Type: Journal Article
• Authors: Lin, Wenpeng; Li, Yuan; Du, Shiqiang; Zheng, Yuanfan; Gao, Jun; Sun, Tengteng
• Is Part Of: Ecological indicators. Volume 104(2019)
• Page Start: 41
• Page End: 47
• Publication Date: 2019-09
• Subjects: Spectral analysis -- Fuel Water Content (FWC) -- Equivalent Water Thickness (EWT) -- Spectral index -- Dust deposition; Environmental monitoring -- Periodicals; Environmental management -- Periodicals; Environmental impact analysis -- Periodicals; Environmental risk assessment -- Periodicals; Sustainable development -- Periodicals; 333.71405
• DOI: 10.1016/j.ecolind.2019.04.074
• Languages: English
• ISSNs: 1470-160X

Abstract

Highlights: The paper provides the evaluation of the influences of dust deposition on estimating leaf water content with spectral indexes. Dust-polluted leaves retained the correlations between the observed water content (Equivalent Water Thickness, EWT and Fuel Water Content, FWC) and spectral indexes. Taking into account the effect of dust deposition, the spectral indexes were correlated with EWT to a consistently stronger extent than with FWC. Dust deposition generally dampened the estimation accuracy of leaf water content. Abstract: Hyperspectral technology has equipped large-scale efforts to estimate leaf water content. In an urban environmental context, these efforts may be hampered by dust deposition on leaves. However, the influence of dust deposition on the accuracy of estimating water content is still to be elucidated. This study aimed to comprehensively analyze the influence of dust deposition on the spectrum-based estimation of water content in Shanghai, China. We measured the amount of dust deposition, water content, and the spectrum of 707 sample leaves. We then derived the spectrum-based indexes of water content and assessed the influence of dust deposition on the performance of such indexes in estimating leaf water content. The results revealed that dust-polluted leaves retained the correlations between the observed water content indexes, which includes Equivalent Water Thickness (EWT) and Fuel Water Content (FWC), with spectrum-based indexes. However, these correlation coefficients dramatically varied with the changes in dust deposition amount. EWT had weaker while FWC got stronger correlation coefficients with spectral indexes for dusty leaves compared with clean cases. The spectral indexes were correlated with EWT at a consistently stronger extent than with FWC, suggesting an advantage of using EWT over FWC to represent the leaf water content. The correlations between EWT and spectral indexes were stronger with leaf samples from the same tree species compared with the case of using leaf samples from mixed species. These findings can strengthen the understanding of the influence of dust pollution on leaf water content estimation using spectral indexes.