Inland Water Quality Project
Water colour measurements acquired from satellite imagery have been shown to be highly suitable to assess the dynamics and ecological state of water bodies. The water colour varies, depending on the concentration of constituents of the optically active components within it, such as chlorophyll, cyanobacterial pigments, organic and inorganic sediments as well as dissolved organic matter.
Figure 1. Fire-impacted and ash-laden water samples taken (from left to right) at Lake Tuggeranong, Pine Island and Uriarra Crossing .
The aLMI method uses spatially and temporally variable specific inherent optical properties (SIOP) which represent different water mass types and result in a more accurate, consistent retrieval of water quality parameters, compared to previous ‘fixed’ parameter approaches and therefore, is well suited for operational implementation on well calibrated data cubes of satellite imagery, such as the Digital Earth Australia (DEA). A collaborative project between CSIRO and Geoscience Australia was initiated to work towards implementing this approach in a nationally applicable inland water monitoring capability with an operational and technical focus. The Inland Water Quality (IWQual) project aims to develop this capability for Australia’s inland waters.
The IWQual project aims to collate and evaluate existing datasets, as well as to expand the breadth of bio-optical data available to characterise Australian inland water types. This data is to be used to parameterise an adaptive linear matrix inversion (aLMI) model developed by CSIRO (Brando, Dekker, Park, & Schroeder, 2012). Since the interim field report (Drayson, Anstee, Kerrisk, Botha, & Ford, 2020) IWQual data collection has significantly expanded sampling at priority waterbodies identified by gap analysis (Botha, Anstee, & Lehmann, 2019; Drayson et al., 2020). The gap analysis identified waterbodies that regularly have bio-optical properties that do not match the previous data sets. These priority waterbodies included alpine lakes and waterbodies east of the Great Dividing Range and were targeted regions of interest for this component of the project shown in the figure below. The next major field trip is the Lake Argyle in Western Australia in August 2021. To our knowledge there has never been bio-optical data collected in this lake and this will form an important part of our calibration and validation activities for satellites.
Figure 2. Sentinel 2B MSI true colour composite image of Lake Burrinjuck (NSW) collected on the 27th of February 2020, showing the brown ash-laden waters entering the north eastern arm near Good Hope through the Murrumbidgee River after the extreme summer bushfires in southern catchments in the ACT. Image acquired from nationalmap.gov.au.
Janet Anstee
- Primary EmailJanet.Anstee@csiro.au
Project Team
Dr Hannelie Botha
- Primary Emailhannelie.botha@csiro.au
Gemma Kerrisk
- Primary Emailgemma.kerrisk@csiro.au
Publications
Anstee JM (2020) IWQual: Inland water quality. Interim Report on Eye on Water – Australia Website Developments, May 2020, CSIRO, Australia.
Anstee JM, Drayson, N (2020) IWQual: Inland water quality. Eye on Water – Australia Workshop Outcomes, April 2021, CSIRO, Australia.
Botha EJ, Anstee JM, Sagar S, Lehmann E, Medeiros TAG. Classification of Australian Waterbodies across a Wide Range of Optical Water Types. Remote Sensing. 2020; 12(18):3018. https://doi.org/10.3390/rs12183018
Botha, E., Anstee, J., & Lehmann, E. (2019). IWQual: Inland water quality, Aquatic reflectance and bio-optics acquisition for validation of Australian inland waters. Gap analysis Report,CSIRO, Australia.
Drayson, N., Anstee, J., Kerrisk, G., Botha, H., & Ford, P. (2020). IWQual: Inland water quality, Aquatic reflectance and biooptics acquisition for validation of Australian inland waters.
Interim Field Report.http://hdl.handle.net/102.100.100/365278?index=1
Drayson N, Kerrisk G, Anstee JM, Botha EJ, Wojtasiewicz B, McLaughlin, J, Hutton M and Ford P (2021) IWQual: Inland water quality, Aquatic reflectance and bio-optics acquisition for validation of Australian inland waters. Final Data Acquisition Report, May 2021, CSIRO, Australia.