冯家江流域水体中氮的空间分布特征

冯家江是北海市区重要的生态廊道。研究冯家江流域水体中氮的空间分布特征、污染来源、影响因素,对掌握冯家江流域氮污染现状及污染防控等具有重要的现实意义。本研究应用地统计学方法分析了冯家江流域地表水及沿岸地下水中氮污染物的空间分布特征。结果表明,地表水中氮污染物呈现出“高氨氮、低硝氮”的特征,NH₃-N质量浓度平均值高达5.42 mg/L,NO₃-N在孔隙潜水中明显富集,其质量浓度最高达32.63 mg/L。城镇生活污染物、人畜粪便及农业生产中化肥的施用是地表水、地下水中氮污染物的主要来源。pH值、氧化还原条件及包气带岩性结构和厚度是影响冯家江流域水体中氮污染物迁移转化的重要因素。

Spatial distribution characteristics of Nitrogen in the water body of Fengjiajiang river

Fengjiajiang river is an important ecological corridor of Beihai town. It is of great importance in understanding the pollution level of Nitrogen and the control and prevention of Nitrogen pollution in Fengjiajiang river, through the investigation of Nitrogen spatial distribution characteristics, pollution sources and influence factors. The spatial distribution characteristics of Nitrogen in the surface water and groundwater were analyzed with geostatistical method. The results show that the Nitrogen concentration in the surface water has the characteristics of high NH₃-N and low NO₃-N, with the average value of NH₃-N 5.42 mg/L. NO₃-N is concentrated in the pore groundwater, with the maximun value of 32.63 mg/L. The main sources of Nitrogen pollution include domestic pollutants, animal and human manure and the usage of chemical fertilizer. The important factors affecting the migration and transformation of Nitrogen pollutants in the water boby of the study area are pH value, redox conditions, lithologic structure and thickness of the unsaturated zone.