Estimation of algal biological parameters using water quality modeling and SPOT satellite data

Discovering biological parameters is the essential step to understand and even control an ecosystem. Traditional in situ sampling is time-consuming, expensive, and can only be taken for small areas with limited samples. It also needs a long-term observation program to acquire biological growth records. In this paper, a novel approach is proposed to estimate algal biological parameters, which are important factors of eutrophication control, by using water quality modeling and remote sensing techniques. Algal growth rate and respiration rate were estimated using a one-dimensional water quality model (QUAL2E) and two-dimension spatially distributed water quality data derived from SPOT satellite imagery for the Te-Chi Reservoir in Taiwan. A nonlinear calibration model was developed by minimizing the average difference between observed and simulated values using a least squares method. The calibration model using a mathematical approach provides an alternative method to estimate biological parameters of algae besides in situ sampling and experiment.