Modeling the BOD of Danube River in Serbia using spatial, temporal, and input variables optimized artificial neural network models

• Published in: Environmental monitoring and assessment 2016-05, Vol.188 (5), p.300-300, Article 300
• Main Authors: Šiljić Tomić, Aleksandra N., Antanasijević, Davor Z., Ristić, Mirjana Đ., Perić-Grujić, Aleksandra A., Pocajt, Viktor V.
• Format: Article
• Language: English
• Subjects: Atmospheric Protection/Air Quality Control/Air Pollution; Biochemical oxygen demand; Biological Oxygen Demand Analysis; Chemical oxygen demand; Cities; Correlation analysis; Datasets; Earth and Environmental Science; Ecology; Ecotoxicology; Environment; Environmental Management; Environmental monitoring; Environmental Monitoring - methods; Hydrology; Laboratories; Metallurgy; Monitoring/Environmental Analysis; Neural networks; Neural Networks (Computer); Optimization; Pollution; Rivers; Rivers - chemistry; Romania; Serbia; Spatio-Temporal Analysis; Water Quality
• ISSN: 0167-6369; 1573-2959
• DOI: 10.1007/s10661-016-5308-1

This paper describes the application of artificial neural network models for the prediction of biological oxygen demand (BOD) levels in the Danube River. Eighteen regularly monitored water quality parameters at 17 stations on the river stretch passing through Serbia were used as input variables. The optimization of the model was performed in three consecutive steps: firstly, the spatial influence of a monitoring station was examined; secondly, the monitoring period necessary to reach satisfactory performance was determined; and lastly, correlation analysis was applied to evaluate the relationship among water quality parameters. Root-mean-square error (RMSE) was used to evaluate model performance in the first two steps, whereas in the last step, multiple statistical indicators of performance were utilized. As a result, two optimized models were developed, a general regression neural network model (labeled GRNN-1) that covers the monitoring stations from the Danube inflow to the city of Novi Sad and a GRNN model (labeled GRNN-2) that covers the stations from the city of Novi Sad to the border with Romania. Both models demonstrated good agreement between the predicted and actually observed BOD values.