Three-dimensional hydrodynamic and water quality model for TMDL development of Lake Fuxian, China.
Three-dimensional hydrodynamic and water quality model for TMDL development of Lake Fuxian, China.
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DOI：
10.1016/s1001-0742(11)60967-4
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发表时间：
2012-08
影响因子：
6.9
通讯作者：
Lei Zhao;Xiaolin Zhang;Y. Liu;B. He;Xiang Zhu;R. Zou;Yuan-Lin Zhu
中科院分区：
文献类型：
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作者：
Lei Zhao;Xiaolin Zhang;Y. Liu;B. He;Xiang Zhu;R. Zou;Yuan-Lin Zhu
抚仙湖是中国最大的深淡水湖。虽然其平均水质达到中国国家水质标准（CNWQS） GB3838-2002的一级标准，但监测数据显示，部分地区水质接近二级阈值。因此，迫切需要通过总最大日负荷（TMDL）方案来降低流域负荷。建立了抚仙湖三维水动力和水质模型，模拟了水体循环和污染物的命运与运移。模型开发过程包括网格生成、初始和边界条件配置以及模型校准过程。该模型准确再现了观测到的水面高程、温度时空变化、总氮（TN）、总磷（TP）和化学需氧量（COD）浓度，为进一步的TMDL分析提供了合理的数值表示原型系统。TMDL是基于最大瞬时地表水浓度和年平均地表水浓度对CNWQS第一类水质标准的两种解释计算得出的。对第一种方案的分析表明，总氮、总磷和总COD负荷分别减少66%、68%和57%。水质是最优先考虑的问题；然而，地方经济发展和降低负荷的成本可行性可能会带来重大问题。在第二次解释中，模型结果表明，在现有条件下，平均水质达到I类标准，因此无需减少负荷。未来的研究需要对现实决策进行风险和成本评估。
Lake Fuxian is the largest deep freshwater lake in China. Although its average water quality meets Class I of the China National Water Quality Standard (CNWQS), i.e., GB3838-2002, monitoring data indicate that the water quality approaches the Class II threshold in some areas. Thus it is urgent to reduce the watershed load through the total maximum daily load (TMDL) program. A three-dimensional hydrodynamic and water quality model was developed for Lake Fuxian, simulating flow circulation and pollutant fate and transport. The model development process consists of several steps, including grid generation, initial and boundary condition configurations, and model calibration processes. The model accurately reproduced the observed water surface elevation, spatiotemporal variations in temperature, and total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) concentrations, suggesting a reasonable numerical representation of the prototype system for further TMDL analyses. The TMDL was calculated using two interpretations of the water quality standards for Class I of the CNWQS based on the maximum instantaneous surface and annual average surface water concentrations. Analysis of the first scenario indicated that the TN, TP and COD loads should be reduced by 66%, 68% and 57%, respectively. Water quality was the highest priority; however, local economic development and cost feasibility for load reduction can pose significant issues. In the second interpretation, the model results showed that, under the existing conditions, the average water quality meets the Class I standard and therefore load reduction is unnecessary. Future studies are needed to conduct risk and cost assessments for realistic decision-making.