Remote sensing of Waikato lakes
Report: TR 2017/12
Author: Mathew Allan (University of Waikato)
The Waikato Regional Council has statutory environmental monitoring requirements, including commitments arising from the National Policy Statement for Freshwater Management. The application of remote sensing obviates the large cost of monitoring all aquatic systems within a region, and although there are limitations in terms of accuracy, useful water quality metrics can still be derived, including timing of algal bloom/turbidity events, broadening the general understanding of aquatic hydrodynamics and ecology. There is also potential for “hindcasting” water quality metrics using historical image archives.
This study explored and utilised existing remote sensing technology and algorithms to determine total suspended sediments (TSS) in lakes at a regional scale, producing a dataset quantifying spatial and temporal variability of remotely sensed TSS (including an experimental algorithm for chlorophyll a concentrations). It is demonstrated that the remote estimation of TSS within Waikato lakes is feasible and provides TSS estimations within the ranges of measured in situ TSS concentrations within most of the Waikato lakes except a small number of lakes with higher than expected estimated TSS concentrations. The derived dataset maybe helpful to elucidate a better understanding of water quality variability and ultimately better understand implications for lake management.
|Table of Contents||7|
|List of figures||8|
|List of tables||9|
|Waikato lakes study site||14|
|Satellite imagery, software and in situ data||16|
|Linear spectral unmixing||18|
|Total suspended solids (TSS)||20|