Estimation of total dissolved solids in Zayandehrood River using intelligent models and PCA

• Published in: Sustainable water resources management 2021-04, Vol.7 (2), Article 22
• Main Authors: Tizro, A. Taheri, Fryar, Alan E., Vanaei, A., Kazakis, N., Voudouris, K., Mohammadi, P.
• Format: Article
• Language: English
• Subjects: Adaptive systems; Artificial neural networks; Calcium; Calcium ions; Clustering; Development Economics; Earth and Environmental Science; Earth Sciences; Fuzzy logic; Hydrogeology; Hydrology/Water Resources; Low flow; Magnesium; Mathematical models; Neural networks; Original Article; Parameters; pH effects; Principal components analysis; River discharge; River flow; Rivers; Sodium; Support vector machines; Sustainable Development; Total dissolved solids; Water Policy/Water Governance/Water Management
• ISSN: 2363-5037; 2363-5045
• DOI: 10.1007/s40899-021-00497-w

Artificial neural networks (ANN), adaptive neuro-fuzzy inference system (ANFIS) with subtractive clustering (ANFIS-SC) and support vector machine models were used to determine total dissolved solids (TDS) of the Zayandehrood River in Iran. In total, nine hydrochemical parameters [Ca 2+ , SO 4 2− , Na + , Cl − , EC, pH, HCO 3 − , Mg 2+ and sodium adsorption ratio (SAR)] were utilized to estimate the TDS of the river at a monthly time scale. Statistical data were categorized into low-flow and wet periods based on river discharge. Principal component analysis (PCA) was used to determine the input of the models. The results indicate that the PCA method, in both wet and low-flow periods, performed suitably based on the evaluation criteria for all models. The parameters of the first component included Ca 2+ , SO 4 2− , Cl − , EC, Mg 2+ and SAR in both periods. In contrast, the parameters pH and HCO 3 − of the second component provided unacceptable precision. The ANFIS-SC model was more precise than the other two models, with an RMSE value of 12.33 meq/l for the first component in the low-flow period. However, the ANN model was most precise in the wet period, with a calculated RMSE value of 13.87 meq/l.