Dynamic analysis of river nitrogen and phosphorus pollution based on loadest model and wavelet transform.
Dynamic analysis of river nitrogen and phosphorus pollution based on loadest model and wavelet transform.
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DOI：
10.3969/j.issn.1004-1524.2020.09.18
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发表时间：
2020-01-01
期刊：
影响因子：
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通讯作者：
Lyu, J.
中科院分区：
文献类型：
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作者：
Jin, Yan-an;Zhang, Bai-fa;Lyu, J.
河流污染物负荷估算及其变化分析是面源污染治理的基础。但低频人工监测无法反映河流水质每日连续变化。基于2003—2016年浙江长乐河出海断面月度水质监测数据，对河流总氮（TN）和总磷（TP）负荷估算的LOADEST模型进行了标定和验证。然后，利用连续流量数据估算了长乐河的日TN和TP负荷。结果表明，2003-2016年，河流TN、TP年平均负荷分别为（2 207.71862.48）t.a-1和（71.4331.56）t.a-1，日平均负荷分别为（6.0411.81）t.d-1和（0.190.26）t.d-1。研究期间TN和TP负荷均呈增加趋势。同时利用小波分析方法分析了研究期间河流TN和TP负荷的变化规律。研究发现，长乐河TN负荷存在周期性变化，主要时间跨度为18个月。 TP负荷的变化与TN负荷的变化相似，但变化强度相对较弱。 TN和TP负荷的小波方差表明TN和TP负荷的周期性变化主要取决于河流流量的周期性变化，而受TN和TP浓度的影响较小。
The estimation of pollutant loads in rivers and the analysis of their variations are the basis for non-point source pollution treatment. However, the low-frequency manual monitoring cannot reflect the daily continuous changes of water quality in rivers. Based on the monthly water quality monitoring data at the outlet section of Changle River in Zhejiang Province from 2003 to 2016, the LOADEST model for total nitrogen (TN) and total phosphorus (TP) load estimation in the river was calibrated and verified. Then, the daily TN and TP loads in the Changle River were estimated by using the continuous flow data. The results showed that, during 2003-2016, the average annual TN and TP loads in the river were (2 207.71862.48) t.a-1 and (71.4331.56) t.a-1, respectively, while their daily average loads were (6.0411.81) t.d-1 and (0.190.26) t.d-1, respectively. Both the TN and TP loads had an increasing trend in the study period. Meanwhile, the variation patterns of TN and TP loads in the river during the research period were analyzed by using wavelet analysis method. It was found that the TN load in the Changle River had periodic changes with a main time span of 18 months. The variation of the TP load was similar to that of the TN load, but the varying intensity was relatively weak. The wavelet variance of TN and TP loads suggested that the periodic variations of TN and TP loads were mainly dependent on the periodic changes of river flow, yet less affected by TN and TP concentrations.