Classification of Australian Waterbodies across a Wide Range of Optical Water Types

Abstract

Baseline determination and operational continental scale monitoring of water quality are required for reporting on marine and inland water progress to Sustainable Development Goals (SDG). This study aims to improve our knowledge of the optical complexity of Australian waters. A workflow was developed to cluster the modelled spectral response of a range of in situ bio-optical observations collected in Australian coastal and continental waters into distinct optical water types (OWTs). Following clustering and merging, most of the modelled spectra and modelled specific inherent optical properties (SIOP) sets were clustered in 11 OWTs, ranging from clear blue coastal waters to very turbid inland lakes. The resulting OWTs were used to classify Sentinel-2 MSI surface reflectance observations extracted over relatively permanent water bodies in three drainage regions in Eastern Australia. The satellite data classification demonstrated clear limnological and seasonal differences in water types within and between the drainage divisions congruent with general limnological, topographical, and climatological factors. Locations of unclassified observations can be used to inform where in situ bio-optical data acquisition may be targeted to capture a more comprehensive characterization of all Australian waters. This can contribute to global initiatives like the SDGs and increases the diversity of natural water in global databases.

Bio-optical properties of the Brazilian Abrolhos Bank’s shallow coral-reef waters

“…However, the ABR biooptical variables had higher values than in reef waters from GBRWHA. According to Botha et al (2020), the GBRWHA and NA has a wide range of water types which could explain the comparison results between ABR and these two different areas. The physical and biogeochemical oceanographic processes associated with inputs of landderived material are responsible for the variation in the biooptical properties of coral reef areas.…”

Australian aquatic bio-optical dataset with applications for satellite calibration, algorithm development and validation

“…Monitoring water pollution using remote sensing offers a greater understanding of spatial and temporal distribution of pollutants than traditional methods of in situ data collection [2 , 3] . The calibration and validation of models used to predict concentrations of optically active constituents (OACs) from remotely sensed data require representative samples from a diverse set of optical water types [2 , 4 , 5] . The dataset described in this article [6] provides a diverse set of bio-optical data collected from Australian inland waterbodies between 2013 and 2021.…”

Bibliometric Analysis of Remote Sensing of Inland Waters Publications from 1985 to 2020

“…Because of these characteristics, case 2 waters have been used to describe inland waters. Nevertheless, the use of these 2 classes (case 1 and case 2) has been disused due to the identification of different optical water types [48,55]. The term "lake" has also been used frequently to describe inland waters once all lakes are located in the continental part.…”