An uncertainty‐based evaluation of sulphuric compounds transport in reservoirs considering sensitivity analysis

• Published in: Water and environment journal : WEJ 2024-11, Vol.38 (4), p.665-677
• Main Authors: Gholizadeh, Fatemeh, Zeynolabedin, Amin, Behboudian, Massoud
• Format: Article
• Language: English
• Subjects: Aeration; ARIMA; Autoregressive models; CE‐QUAL‐W2 model; Dam construction; Dams; Deep water; Demand analysis; Dissolved oxygen; Dissolved solids; Drinking water; environment; Fluctuations; Hydrogen sulfide; Hydrogen sulphide; Iran; Monitoring; Monte Carlo simulation; nitrates; oxygen; Reservoirs; Seasonal variations; Sediments; Sensitivity analysis; Stratification; Sulfates; Sulphides; sulphur compounds; time series analysis; Total dissolved solids; Uncertainty; Uncertainty analysis; water; Water demand; Water monitoring; Water quality; Water quality management; Water quality standards; Water resources; Water supply
• ISSN: 1747-6585; 1747-6593
• DOI: 10.1111/wej.12953

Deepwater bodies such as dam reservoirs are among the most prominent water resources that supply societies' water demand. Hence, water quality in these resources requires continuous and meticulous monitoring. This study evaluated the water quality of Changuleh Dam, a dam under construction in western Iran, using the CE‐QUAL‐W2 model to predict fluctuations in sulphate (SO42−) and hydrogen sulphide (H2S) concentrations. A sensitivity analysis was conducted to assess the dependence of model outputs on input variables. Additionally, an uncertainty analysis was performed using MATLAB to address the inherent uncertainties of the input variables through an ARIMA (2, 2, 1) time series model and Monte Carlo simulations. The results indicated a high sulphate concentration averaging 955.6 mg/l, considerably exceeding the drinking water standard of 400 mg/l, identifying the reservoir as a sulphate‐rich water resource. Seasonal fluctuations of H2S concentrations were also observed in the reservoir's anaerobic bed sediments, peaking at 87 mg/l. The sensitivity analysis showed that nitrate and total dissolved solids (TDS) varied more noticeably than dissolved oxygen (DO) at different depths, with the greatest variation at 50 m. This study highlights the critical need for continuous and meticulous monitoring of water quality in dam reservoirs to meet water supply standards. Highlights Sulfate concentrations in the reservoir exceeded drinking water standards, averaging 955.6 mg/l. Hydrogen sulfide concentrations peaked at 87 mg/l during seasonal stratification. Sensitivity analysis revealed that nitrate and TDS were more impacted by input variations than dissolved oxygen. Uncertainty analysis indicated the greatest fluctuations in sulfate and hydrogen sulfide concentrations at a depth of 50 m. Aeration of the reservoir is recommended to reduce hydrogen sulfide levels and maintain water quality.