Modeling daily chlorophyll a dynamics in a German lowland river using artificial neural networks and multiple linear regression approaches

Wu, N; Huang, J; Schmalz, B; Fohrer, N

HERO ID

2283567

Reference Type

Journal Article

Year

2014

Language

English

HERO ID 2283567
In Press No
Year 2014
Title Modeling daily chlorophyll a dynamics in a German lowland river using artificial neural networks and multiple linear regression approaches
Authors Wu, N; Huang, J; Schmalz, B; Fohrer, N
Journal Limnology
Volume 15
Issue 1
Page Numbers 47-56
Abstract Phytoplankton biomass is an important indicator for water quality, and predicting its dynamics is thus regarded as one of the important issues in the domain of river ecology and management. However, the vast majority of models in river systems have focused mostly on flow prediction and water quality with very few applications to biotic parameters such as chlorophyll a (Chl a). Based on a 1.5-year measured dataset of Chl a and environmental variables, we developed two modeling approaches [artificial neural networks (ANN) and multiple linear regression (MLR)] to simulate the daily Chl a dynamics in a German lowland river. In general, the developed ANN and MLR models achieved satisfactory accuracy in predicting daily dynamics of Chl a concentrations. Although some peaks and lows were not predicted, the predicted and the observed data matched closely by the MLR model with the coefficient of determination (R (2)), Nash-Sutcliffe efficiency (NS), and the root mean square error (RMSE) of 0.53, 0.53, and 2.75 for the calibration period and 0.63, 0.62, and 1.94 for the validation period, respectively. Likewise, the results of the ANN model also illustrated a good agreement between observed and predicted data during calibration and validation periods, which was demonstrated by R (2), NS, and RMSE values (0.68, 0.68, and 2.27 for the calibration period, 0.55, 0.66 and 2.12 for the validation period, respectively). According to the sensitivity analysis, Chl a concentration was highly sensitive to dissolved inorganic nitrogen, nitrate-nitrogen, autoregressive Chl a, chloride, sulfate, and total phosphorus. We concluded that it was possible to predict the daily Chl a dynamics in the German lowland river based on relevant environmental factors using either ANN or MLR models. The ANN model is well suited for solving non-linear and complex problems, while the MLR model can explicitly explore the coefficients between independent and dependent variables. Further studies are still needed to improve the accuracy of the developed models.
Doi 10.1007/s10201-013-0412-1
Wosid WOS:000329834800005
Url <Go to ISI>://WOS:000329834800005
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Keyword Artificial neural networks; Daily chlorophyll a; Multiple linear regression; Models; Watershed management
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