Algal bloom prediction by support vector machine and relevance vector machine with genetic algorithm optimization in freshwater reservoirs
Abstract
Purpose
The purpose of this paper is to examine the applicability and capability of models based on a genetic algorithm and support vector machine (GA-SVM) and a genetic algorithm and relevance vector machine (GA-RVM) for the prediction of phytoplankton abundances associated with algal blooms in a Macau freshwater reservoir, and compare their performances with an artificial neural network (ANN) model.
Design/methodology/approach
The hybrid models GA-SVM and GA-RVM were developed for the optimal control of parameters for predicting (based on the current month’s variables) and forecasting (based on the previous three months’ variables) phytoplankton dynamics in a Macau freshwater reservoir, MSR, which has experienced cyanobacterial blooms in recent years. There were 15 environmental parameters, including pH, SiO2, alkalinity, bicarbonate (HCO3−), dissolved oxygen (DO), total nitrogen (TN), UV254, turbidity, conductivity, nitrate (NO3−), orthophosphate (PO43−), total phosphorus (TP), suspended solids (SS) and total organic carbon (TOC) selected from the correlation analysis, with eight years (2001-2008) of data for training, and the most recent three years (2009-2011) for testing.
Findings
For both accuracy performance and generalized performance, the ANN, GA-SVM and GA-RVM had similar predictive powers of R2 of 0.73-0.75. However, whereas ANN and GA-RVM models showed very similar forecast performances, GA-SVM models had better forecast performances of R2 (0.862), RMSE (0.266) and MAE (0.0710) with the respective parameters of 0.987, 0.161 and 0.032 optimized using GA.
Originality/value
This is the first application of GA-SVM and GA-RVM models for predicting and forecasting algal bloom in freshwater reservoirs. GA-SVM was shown to be an effective new way for monitoring algal bloom problem in water resources.
Keywords
Acknowledgements
The authors thank Macao Water Co. Ltd. for providing historical data of water quality parameters and phytoplankton abundances. Financial support was received from the Fundo para o Desenvolvimento das Ciências e da Tecnologia (FDCT) (Grant # FDCT/069/2014/A2), and the authors gratefully acknowledge the Research Committee at the University of Macau. Author Inchio Lou is deceased.
Citation
Wang, Y., Xie, Z., Lou, I., Ung, W.K. and Mok, K.M. (2017), "Algal bloom prediction by support vector machine and relevance vector machine with genetic algorithm optimization in freshwater reservoirs", Engineering Computations, Vol. 34 No. 2, pp. 664-679. https://doi.org/10.1108/EC-11-2015-0356
Publisher
:Emerald Publishing Limited
Copyright © 2017, Emerald Publishing Limited