Abstract: Billabongs in tropical northern Australia are under increasing pressure from environmental stressors. There is a need for methods to monitor the water-quality dynamics of these often remote ecosystems. This study assessed the capacity of ultra-high resolution Remotely Piloted Aircraft System (RPAS) imagery and remote sensing methods to quantify the water turbidity. I investigated water quality calibration algorithms under turbid inland water conditions and developed a reflectance-based approach to map billabong turbidity. Five bands of hyper spectral digital data were collected from sensors on board RPAS and the observations of turbidity values were obtained near-simultaneously using turbidity sensors on a radio controlled boat. The relationships between reflectance and water turbidity were assessed using single-band reflectance, band ratios, and water-related indices. Results show the Normalised Difference Water Index (NDWI) is a good indicator for water turbidity. Its linear model had a coefficient of determination of 0.7231. This study developed a new method to process multi-spectral RPAS imagery for turbidity monitoring in inland water bodies.
Authors: Hua Chen
Associations: Charles Darwin University