Stepwise Automatic Calibration of Large-Scale Water Quality Model for Evaluation of Thermal Stratification and Eutrophication in Water Reservoir

This research addresses the essential need for assessing and managing water quality in reservoirs, which play a pivotal role in various socioeconomic aspects. To achieve this, a stepwise automatic calibration approach is proposed, specifically targeting the CE-QUAL-W2 model. This two-dimensional hydrodynamic and water quality model is widely employed in studies worldwide. Calibration, a fundamental aspect of model development, is complex and traditionally relies on manual, trial-and-error methods, which can be time-consuming and require substantial expertise. In this study, an alternative approach is introduced, incorporating the JAYA optimization algorithm, which reduces the complexity associated with fine-tuning optimization parameters. Furthermore, a clustering framework is adopted, grouping related variables for independent calibration. The research is conducted on the Dez reservoir in southwest Iran, using a two-step calibration process. The first step focuses on hydrodynamics, while the second step addresses water quality variables, including phosphate, ammonium, nitrate, and dissolved oxygen. The proposed methodology applied to Dez reservoir and tested against the observed data, where it demonstrates promising results.