| 引用本文: | 李玉庆,张 存,张文贤.水稻灌区农业面源污染物迁移转化规律模拟研究[J].灌溉排水学报,2017,36(11):29-35. |
| LI Yuqing,ZHANG Cun,ZHANG Wenxian.水稻灌区农业面源污染物迁移转化规律模拟研究[J].灌溉排水学报,2017,36(11):29-35. |
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| 摘要: |
| 模拟水稻灌区中非自然水文过程及其驱动下的面源污染物迁移转化过程对了解水稻灌区面源污染形成机理以及污染控制具有重要的意义。将水稻灌区水文过程分为陆面水文过程和排水沟道水文过程，采用均衡法模拟陆面水文过程中稻田深层渗漏水量以及氨氮（NH4+）、硝氮（NO3-）和磷酸根(PO43-）的渗漏通量，在此基础上，基于非稳定饱和渗流方程计算稻田深层渗漏过程所形成的侧向排水过程，作为排水沟道水文过程的输入项，基于动力波方程和一阶动力学方程描述了水稻灌区排水网络下的面源污染物运移和转化过程，提出了水稻灌区农业面源污染物迁移转化模型。根据前郭灌区2008—2009年的监测数据对模型渗流过程、主要面源污染物迁移转化过程参数进行率定，采用2010年的监测资料对模拟结果进行了验证。结果表明，基于所提出的方法模拟了稻田和排水沟道2个水文过程中NH4+，NO3- 和PO43-的质量浓度峰值过程的差异，实现了水稻灌区陆面水文和排水沟水文过程的耦合。稻田水层中模拟NH4+，NO3- 和PO43-的Nash-Sutcliffe系数分别为0.772、0.758和0.709，相对均方根误差（RMSE）分别为0.042、0.050和0.071，排水系统中模拟NH4+、NO3- 和PO43- 污染物的Nash-Sutcliffe系数分别为0.645、0.704和0.854，相对均方根误差（rRMSE）分别为0.072、0.060和0.031。所提出的方法可有效地模拟稻田渗流过程和排水过程中的面源污染物迁移转化过程。 |
| 关键词: 面源污染； 水稻灌区； 一阶动力学方程； 模拟 |
| DOI：10.13522/j.cnki.ggps.2017.11.006 |
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| Simulating the Transport and Transformation of Non-point Contaminants in Paddy Field within a Irrigated District |
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LI Yuqing， ZHANG Cun， ZHANG Wenxian
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Xizang Agriculture and Animal Husbandry College, Nyingchi 860000, China
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| Abstract: |
| Simulating transport and transformation of contaminantsin irrigated paddy fields is essential to understand the mechanisms underlying their movement and accumulation, providing guidance to remediation strategies. In this paper, we divided paddy field water into surface and subsurface waters. The leaching of surface water and the dissolved solute NH4+, NO3- and PO43- within it were calculated using water-balance method. Water in the soil was simulated numerically from transient flow equation, from which we calculated the discharge rate to drainage ditch. Water flow in the drainage network was simulated using the wave equation and the biochemical reaction of the solutes was described by first-order kinetics. We then applied the model to Qianguo Irrigation District. The data measured over 2008—2009 were used to estimated the model parameters, and the model was validated against the data measured in 2010. The results showed that the model was capable of reproducing the breakthrough curves of these solutes in both surface and subsurface water. The Nash-Sutcliffe coefficient of the concentrations of NH4+, NO3- and PO43- simulated from the model was 0.772, 0.758 and 0.709 respectively, with their associated root-mean-square error being 0.645, 0.70 and 0.854 and relative root-mean-square error being 0.072, 0.060 and 0.031 respectively. |
| Key words: agricultural non-point source pollution; rice irrigation district; first order kinetic equation; simulation |
