Optical types of inland and coastal waters

Evangelos Spyrakos, Ruth O'Donnell, Peter D. Hunter, Claire Miller, Marian Scott, Stefan G.H. Simis, Claire Neil, Claudio C.F. Barbosa, Caren E. Binding, Shane Bradt, Mariano Bresciani, Giorgio Dall'Olmo, Claudia Giardino, Anatoly A. Gitelson, Tiit Kutser, Lin Li, Bunkei Matsushita, Victor Martinez-Vicente, Mark W. Matthews, Igor OgashawaraAntonio Ruiz-Verdú, John Schalles, Emma Tebbs, Yunlin Zhang, Andrew N. Tyler

Research output: Contribution to journalArticle

42 Scopus citations

Abstract

Inland and coastal waterbodies are critical components of the global biosphere. Timely monitoring is necessary to enhance our understanding of their functions, the drivers impacting on these functions and to deliver more effective management. The ability to observe waterbodies from space has led to Earth observation (EO) becoming established as an important source of information on water quality and ecosystem condition. However, progress toward a globally valid EO approach is still largely hampered by inconsistences over temporally and spatially variable in-water optical conditions. In this study, a comprehensive dataset from more than 250 aquatic systems, representing a wide range of conditions, was analyzed in order to develop a typology of optical water types (OWTs) for inland and coastal waters. We introduce a novel approach for clustering in situ hyperspectral water reflectance measurements (n = 4045) from multiple sources based on a functional data analysis. The resulting classification algorithm identified 13 spectrally distinct clusters of measurements in inland waters, and a further nine clusters from the marine environment. The distinction and characterization of OWTs was supported by the availability of a wide range of coincident data on biogeochemical and inherent optical properties from inland waters. Phylogenetic trees based on the shapes of cluster means were constructed to identify similarities among the derived clusters with respect to spectral diversity. This typification provides a valuable framework for a globally applicable EO scheme and the design of future EO missions.

Original languageEnglish (US)
Pages (from-to)846-870
Number of pages25
JournalLimnology and Oceanography
Volume63
Issue number2
DOIs
StatePublished - Mar 1 2018

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All Science Journal Classification (ASJC) codes

  • Oceanography
  • Aquatic Science

Cite this

Spyrakos, E., O'Donnell, R., Hunter, P. D., Miller, C., Scott, M., Simis, S. G. H., Neil, C., Barbosa, C. C. F., Binding, C. E., Bradt, S., Bresciani, M., Dall'Olmo, G., Giardino, C., Gitelson, A. A., Kutser, T., Li, L., Matsushita, B., Martinez-Vicente, V., Matthews, M. W., ... Tyler, A. N. (2018). Optical types of inland and coastal waters. Limnology and Oceanography, 63(2), 846-870. https://doi.org/10.1002/lno.10674