Highlights

• For the first time, using long term field data researchers compared and validated the performance of two representative types of beach-water-quality forecast models, i.e., a three-dimensional (3D) hydrodynamic model and a multiple linear regression (MLR) model. The outcome enables better beach water quality forecast systems for protection of public health.
• Based on a multi-year field validation (2011–2018), both the 3D and MLR models outperform traditional observation-based methods. The MLR model is slightly more accurate in daily E. coli level predictions, while the 3D model better predicts water quality standard exceedances and captures diurnal variations.
• With consistent performance, these models are vital for real-time water quality forecasting and environmental management in smart cities. They showed higher effectiveness in improving public health protection compared to in-effective conventional beach advisories based purely on past weekly or monthly data.

Summary

Researchers have comprehensively evaluated a unique system designed for predicting beach water quality. The evaluation focuses on its application over a decade in Hong Kong. The study is critical as it addresses the public health concerns associated with swimming in fecally polluted waters.

This research stands out for its long-term approach to analyzing the efficacy of two distinct models – a three-dimensional (3D) deterministic hydrodynamic model and a multiple linear regression (MLR) model – in forecasting water quality. The study involves a detailed comparison of these two models in their ability to predict Escherichia coli (E. coli) concentrations, which is a key indicator of fecal pollution under various environmental and pollution conditions.

The findings reveal that both models surpass the performance of existing advisory systems that rely solely on historical data. Although the MLR model is simpler, it shows higher accuracy in general predictions. On the other hand, the 3D model excels in predicting instances when water quality exceeds safety standards.

The combination of these two models within the WATERMAN system significantly enhances the management of beach water quality. This system provides more accurate forecasts and offers timely public advisories and alerts, contributing to improved public health protection.

W. Choi, S. N. Chan, and J. H. W. Lee, “The WATERMAN system for daily beach water quality forecasting: a ten-year retrospective,” Environ Fluid Mech, vol. 23, no. 2, pp. 205–228, Feb. 2022, doi: .