排水沟渠水-底泥-植物协同作用下非点源溶质氮运移模拟研究

发布时间：2019-05-10 21:35

【摘要】：沟渠系统"过程拦截"是现阶段农业非点源污染控制和管理的重要手段。针对当前农田排水沟渠水体-底泥-植物系统内各介质间非点源溶质迁移转化机制不清的现状,在简要分析农田排水沟渠水-底泥-植物复合生态结构及其各组分功能特征的基础上,以沟渠中水体为中心,解析了非点源溶质氮在沟渠系统单一介质以及不同介质间的迁移转化过程;考虑到排水沟渠中水体和污染物均以沿沟渠方向线性迁移为主,应用水流连续方程和非保守性污染物迁移扩散方程,构建了农田排水及其中非点源污染物在排水沟渠中的一维迁移模型,并结合试验沟渠具体情况进行了适度简化;通过内业可控性监测试验,同时提出了沟渠系统水-底泥-植物不同介质对水体中非点源污染物衰减程度影响的量化计算方法;将所建模型与计算参数应用于野外试验沟渠,以氨态氮和硝酸盐氮为例进行模拟,结果表明模拟结果与实测值结合较好,其中氨态氮模拟效率系数为0.87,硝态氮模拟效率系数0.93,表明所建模型及模拟手段符合试验沟渠实际情况,具有较好的适用性。
[Abstract]:Process interception of ditch system is an important means of agricultural non-point source pollution control and management at present. In view of the current situation that the migration and transformation mechanism of non-point source solute between different media in farmland drainage ditch water, sediment and plant system is not clear, Based on the brief analysis of the compound ecological structure of water, sediment and plant in farmland drainage ditch and its functional characteristics, the water body in the ditch is taken as the center. The migration and transformation process of non-point source solute nitrogen between single medium and different media in ditch system is analyzed. Considering that the water body and pollutants in the drainage ditch are mainly transported linearly along the channel direction, the continuous flow equation and the non-conservative pollutant transport and diffusion equation are applied. The one-dimensional migration model of farmland drainage and non-point source pollutants in drainage ditch is constructed, and the appropriate simplification is carried out according to the specific situation of the test ditch. Through the internal controllable monitoring test, the quantitative calculation method of the influence of different media of water, sediment and plant on the attenuation degree of non-point source pollutants in water body is put forward at the same time. The model and the calculated parameters are applied to the field test ditch. Taking ammonia nitrogen and nitrate nitrogen as examples, the results show that the simulation results are well combined with the measured values, and the simulation efficiency coefficient of ammonia nitrogen is 0.87. The simulation efficiency coefficient of nitrate nitrogen is 0.93, which indicates that the model and simulation method are in accordance with the actual situation of the test ditch and have good applicability.
【作者单位】：黄河水利委员会黄河水利科学研究院;
【基金】：国家自然科学基金项目(51379085)资助~~
【分类号】：X71;X52

【相似文献】