Next Article in Journal
Identifying Vegetation in Arid Regions Using Object-Based Image Analysis with RGB-Only Aerial Imagery
Previous Article in Journal
Trends in Remote Sensing Accuracy Assessment Approaches in the Context of Natural Resources
Previous Article in Special Issue
Using Optical Water Types to Monitor Changes in Optically Complex Inland and Coastal Waters
Open AccessArticle

The Effect of Mineral Sediments on Satellite Chlorophyll-a Retrievals from Line-Height Algorithms Using Red and Near-Infrared Bands

Water Science and Technology Directorate, Environment and Climate Change Canada, 867 Lakeshore Rd, Burlington, ON L7S 1A1, Canada
*
Author to whom correspondence should be addressed.
Remote Sens. 2019, 11(19), 2306; https://doi.org/10.3390/rs11192306
Received: 12 August 2019 / Revised: 24 September 2019 / Accepted: 27 September 2019 / Published: 3 October 2019
Red and near-infrared line-height algorithms such as the maximum chlorophyll index (MCI) are often considered optimal for remote sensing of chlorophyll-a (Chl-a) in turbid eutrophic waters, under the assumption of minimal influence from mineral sediments. This study investigated the impact of mineral turbidity on line-height algorithms using MCI as a primary example. Inherent optical properties from two turbid eutrophic lakes were used to simulate reflectance spectra. The simulated results: (1) confirmed a non-linear relationship between Chl-a and MCI; (2) suggested optimal use of the MCI at Chl-a < ~100 mg/m3 and saturation of the index at Chl-a ~300 mg/m3; (3) suggested significant variability in the MCI:Chl-a relationship due to mineral scattering, resulting in an RMSE in predicted Chl-a of ~23 mg/m3; and (4) revealed elevated Chl a retrievals and potential false positive algal bloom reports for sediment concentrations > 20 g/m3. A novel approach combining both MCI and its baseline slope, MCIslope reduced the RMSE to ~5 mg/m3. A quality flag based on MCIslope was proposed to mask erroneously high Chl-a retrievals and reduce the risk of false positive bloom reports in highly turbid waters. Observations suggest the approach may be valuable for all line-height-based Chl-a algorithms. View Full-Text
Keywords: chlorophyll-a; sediment; maximum chlorophyll index; MCI; line-height algorithms; inland water; water quality chlorophyll-a; sediment; maximum chlorophyll index; MCI; line-height algorithms; inland water; water quality
Show Figures

Graphical abstract

MDPI and ACS Style

Zeng, C.; Binding, C. The Effect of Mineral Sediments on Satellite Chlorophyll-a Retrievals from Line-Height Algorithms Using Red and Near-Infrared Bands. Remote Sens. 2019, 11, 2306.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop