Performance Improvement of Biological BOD in Rivers based on De-noising Comparison Wavelet-ANN Conjunction, GP, ANN and MLR Methods (Case Study:Karaj Dam Outlet Station)

Document Type : Research Article

Authors

Civil Engineering Department, University of Qom, Qom, Iran

Abstract

This study considered artificial neural network (ANN), multi-linear regression (MLR), Genetic
Programming (GP) and wavelet analysis and ANN combination (WANN), models for monthly water
biological oxygen demand (BOD) in station Karaj Dam outlet and investigates the effects of data
preprocessing on model performance using discrete wavelet. For this purpose, In the first proposed
model, observed time series of BOD were decomposed into several subtime series at different scales by
discrete wavelet transform. Then these subtime series were imposed as inputs to the ANN method. In
the second proposed model, observed time series of BOD were decomposed at ten scales by wavelet
analysis. Then, total effective time series BOD were imposed as inputs to the neural network model for
prediction of BOD in one month ahead. Results showed that the wavelet neural network models
performance was better in prediction rather than the neural network and multilinear regression
models. The wavelet analysis model produced reasonable predictions for the extreme values. This
model dropped the mean absolute percentage error for the MLR, GP, ANN and the first hybrid
models from 1.87, 0.91, 0.65 and 0.46 respectively, to 0.44 and increased the Nash-Sutcliffe model
efficiency coefficient from 0.23, 0.53, 0.73 and 0.81 to 0.83.

Keywords

Main Subjects


[1] A., Najah; A., Elshafie; O., Karimi; O., Jaffer; Prediction of Johor river water quality parameters using artificial neural networks, European Journal of Scientific Research, Vol. 28, pp. 422-435, 2009.
[2] T., Rajaee; A., Mirbagheri; The suspended load model of rivers using artificial neural networks, Journal of Ferdowsi university of Mashhad engineering faculty,Vol. 21, pp. 1-11, 2009 ().
[3] S.E., Kim; I.W., Seo; Artificial Neural Network ensemble modeling with conjunctive data clustering for water quality prediction in rivers, Journal of Hydro-environment Research, Vol. 9, No. 3, pp.1-15, 2015.
[4] O.,Makarynskyy; D., Makarynska; M., Rayson; S.,Langtry; Combining deterministic modelling with artificial neural networks for suspended sediment estimates, Applied Soft Computing, Vol. 35, pp. 247–256, 2015.
[5] V., Nourani; M.T., Alami; M.H., Aminfar; A Combined Neural-Wavelet Model for Prediction of Ligvanchai Watershed Precipitation, Engineering Application of Artificial Intelligence, Vol. 22, No. 3, pp.146-477, 2009.
[6] T., Rajaee; Wavelet-ANN combination model for prediction of daily suspended sediment load in rivers, Science of The Total Environment,Vol. 409, No. 15, pp. 2917- 2928, 2011.
[7] T., Rajaee; V., Nourani; M., Zounemat-Kermani; O., Kisi;River Suspended Sediment Load Prediction: Application of ANN and Wavelet Conjunction Model, Journal of Hydrologic Engineering, Vol. 16, pp.613-627, 2011.
[8] R.M., Singh; Wavelet-ANN Model for Flood Events,Advances in Intelligent and Soft Computing, Vol. 131,pp.165-175, 2012.
[9] Xu ., Longqin; Liu., Shuangyin; Study of short-term water quality prediction model based on wavelet neural network, athematical and Computer Modelling, Vol.58, pp.807-813, 2013.
[10] V., Nourani; A., Hosseini Baghanam; A., Adamowski;M., Gebremichael; Using self-organizing maps and wavelet transforms for space–time pre-processing of satellite precipitation and run off data in neural network based rainfall–runoff modeling, Journal of Hydrology,Vol. 476, pp.228-243, 2013.
[11] L., Shuangyin; A hybrid WA-CPSO-LSSVR model for dissolved oxygen content prediction in crab culture,Engineering Applications of Artificial Intelligence, Vol,29, pp.114-124, 2014.
[12] M., Alizadeh; M., Kavianpour; Development of wavelet-ANN models to predict water quality parameters in Hilo Bay, Marine Pollution Bulletin, Vol. 98, No. 1-2, pp. 171-178, 2015.
[13] Z., Jamshidzadeh; M.R., Alavi moghadam; Assessment of surface water quality based on CWQI index,Proceedings of the National Conference on Flow and Water Pollution, pp.1-10, 1385 (In Persian).
[14] S., Haykin; Neural Networks: a comprehensive foundation, MacMillan,New York, 1994.
[15] J.G., Han; W.X., Ren; Z.S., Sun; Wavelet packet based damage identification of beam structures, International Journal of Solids and Structures, Vol. 42, No. 26, pp.6610-6627, 2005.
[16] J., Adamowski; F. H., Chan; A wavelet neural network conjunction model for groundwater level forecasting,Journal of ydrology, Vol. 407, No. 1-4, pp.28- 40, 2011.