Croucher Laboratory of Environmental Hydraulics, Department of Civil Engineering, The University of Hong Kong, Hong Kong.
Water Res. 2013 Mar 15;47(4):1631-47. doi: 10.1016/j.watres.2012.12.026. Epub 2012 Dec 27.
Bacterial level (e.g. Escherichia coli) is generally adopted as the key indicator of beach water quality due to its high correlation with swimming associated illnesses. A 3D deterministic hydrodynamic model is developed to provide daily water quality forecasting for eight marine beaches in Tsuen Wan, which are only about 8 km from the Harbour Area Treatment Scheme (HATS) outfall discharging 1.4 million m(3)/d of partially-treated sewage. The fate and transport of the HATS effluent and its impact on the E. coli level at nearby beaches are studied. The model features the seamless coupling of near field jet mixing and the far field transport and dispersion of wastewater discharge from submarine outfalls, and a spatial-temporal dependent E. coli decay rate formulation specifically developed for sub-tropical Hong Kong waters. The model prediction of beach water quality has been extensively validated against field data both before and after disinfection of the HATS effluent. Compared with daily beach E. coli data during August-November 2011, the model achieves an overall accuracy of 81-91% in forecasting compliance/exceedance of beach water quality standard. The 3D deterministic model has been most valuable in the interpretation of the complex variation of beach water quality which depends on tidal level, solar radiation and other hydro-meteorological factors. The model can also be used in optimization of disinfection dosage and in emergency response situations.
细菌水平（例如大肠杆菌）通常被用作海滩水质的关键指标，因为它与游泳相关疾病有很高的相关性。建立了一个 3D 确定性水动力模型，为荃湾区的 8 个海滩提供每日水质预测，这些海滩距离处理 140 万立方米/天部分处理污水的港湾区域污水处理厂（HATS）排放口仅约 8 公里。研究了 HATS 污水的归宿和输移及其对附近海滩大肠杆菌水平的影响。该模型的特点是近场射流混合与海底排放口污水的远场输送和扩散的无缝耦合，以及专门为亚热带香港水域开发的时空相关大肠杆菌衰减率公式。该模型对海滩水质的预测已经通过 HATS 污水消毒前后的现场数据进行了广泛验证。与 2011 年 8 月至 11 月的每日海滩大肠杆菌数据相比，该模型在预测海滩水质标准的达标/超标情况方面的总体准确率为 81-91%。3D 确定性模型在解释海滩水质的复杂变化方面最有价值，这些变化取决于潮汐水平、太阳辐射和其他水文气象因素。该模型还可用于优化消毒剂量和应对紧急情况。
