PMID- 36459893 OWN - NLM STAT- MEDLINE DCOM- 20230105 LR - 20230111 IS - 1879-2448 (Electronic) IS - 0043-1354 (Linking) VI - 229 DP - 2023 Feb 1 TI - A novel approach for estimating and predicting uncertainty in water quality index model using machine learning approaches. PG - 119422 LID - S0043-1354(22)01367-7 [pii] LID - 10.1016/j.watres.2022.119422 [doi] AB - With the significant increase in WQI applications worldwide and lack of specific application guidelines, accuracy and reliability of WQI models is a major issue. It has been reported that WQI models produce significant uncertainties during the various stages of their application including: (i) water quality indicator selection, (ii) sub-index (SI) calculation, (iii) water quality indicator weighting and (iv) aggregation of sub-indices to calculate the overall index. This research provides a robust statistically sound methodology for assessment of WQI model uncertainties. Eight WQI models are considered. The Monte Carlo simulation (MCS) technique was applied to estimate model uncertainty, while the Gaussian Process Regression (GPR) algorithm was utilised to predict uncertainties in the WQI models at each sampling site. The sub-index functions were found to contribute to considerable uncertainty and hence affect the model reliability - they contributed 12.86% and 10.27% of uncertainty for summer and winter applications, respectively. Therefore, the selection of sub-index function needs to be made with care. A low uncertainty of less than 1% was produced by the water quality indicator selection and weighting processes. Significant statistical differences were found between various aggregation functions. The weighted quadratic mean (WQM) function was found to provide a plausible assessment of water quality of coastal waters at reduced uncertainty levels. The findings of this study also suggest that the unweighted root means squared (RMS) aggregation function could be potentially also used for assessment of coastal water quality. Findings from this research could inform a range of stakeholders including decision-makers, researchers, and agencies responsible for water quality monitoring, assessment and management. CI - Copyright (c) 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved. FAU - Uddin, Md Galal AU - Uddin MG AD - Civil Engineering, School of Engineering, College of Science and Engineering, University of Galway, Ireland; Ryan Institute, University of Galway, Ireland; MaREI Research Centre, University of Galway, Ireland. Electronic address: u.mdgalal1@nuigalway.ie. FAU - Nash, Stephen AU - Nash S AD - Civil Engineering, School of Engineering, College of Science and Engineering, University of Galway, Ireland; Ryan Institute, University of Galway, Ireland; MaREI Research Centre, University of Galway, Ireland. FAU - Rahman, Azizur AU - Rahman A AD - School of Computing, Mathematics and Engineering, Charles Sturt University, Wagga Wagga, Australia; The Gulbali Institute of Agriculture, Water and Environment, Charles Sturt University, Wagga Wagga, Australia. FAU - Olbert, Agnieszka I AU - Olbert AI AD - Civil Engineering, School of Engineering, College of Science and Engineering, University of Galway, Ireland; Ryan Institute, University of Galway, Ireland; MaREI Research Centre, University of Galway, Ireland. LA - eng PT - Journal Article DEP - 20221125 PL - England TA - Water Res JT - Water research JID - 0105072 SB - IM MH - *Water Quality MH - *Environmental Monitoring/methods MH - Reproducibility of Results MH - Uncertainty MH - Computer Simulation OTO - NOTNLM OT - Cork harbour OT - Gaussian processes regression OT - Monte Carlo simulation OT - Uncertainty OT - Water quality index COIS- Declaration of Competing Interest The authors state that they did not experience competing financial interests or personal relationships that could have been influenced by the work reported in this paper. EDAT- 2022/12/03 06:00 MHDA- 2023/01/06 06:00 CRDT- 2022/12/02 18:24 PHST- 2022/07/21 00:00 [received] PHST- 2022/11/20 00:00 [revised] PHST- 2022/11/23 00:00 [accepted] PHST- 2022/12/03 06:00 [pubmed] PHST- 2023/01/06 06:00 [medline] PHST- 2022/12/02 18:24 [entrez] AID - S0043-1354(22)01367-7 [pii] AID - 10.1016/j.watres.2022.119422 [doi] PST - ppublish SO - Water Res. 2023 Feb 1;229:119422. doi: 10.1016/j.watres.2022.119422. Epub 2022 Nov 25.