摘要
建立水质模型是探究鄱阳湖水质变化的有效手段,而模型中各参数值的确定对模型精度影响较大。基于MIKE21构建水动力水质耦合模型,采用扰动法对各参数进行敏感性分析,以鄱阳湖主流向六个代表性点处的总无机氮为输出变量,计算敏感性指标S。结果表明:湖内六点对各参数的敏感程度有差异,中游点2处对各参数最为敏感,有机物降解生成氨氮比率是特别敏感参数。研究可为后续模型中的参数率定提供重要依据,提高模型的精度。
The establishment of water quality model is an effective means to explore the change of water quality on Poyang Lake,and the determination of parameter values in the model has a great influence on the accuracy of the model. Based on MIKE21 software,the coupled model of hydrodynamic and water quality was constructed. The sensitivity analyses of parameters were carried out by the perturbation method. Total inorganic nitrogen of the six representative points in Poyang lake was taken as the output variable to calculate the sensitivity index S. The results show that the parametric sensitivity extent is different for six points,and the second point is the most sensitive to each parameter,the degradation ratio of ammonia to nitrogen by organic matter is particularly sensitive. The research can provide an important basis for parameters calibration in the subsequent procedure,improve the accuracy of the model.
引文
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