包头南海湖冰封期不同形态氮的空间分布

摘要

为探究包头南海湖冰封期不同形态氮空间分布特征及变化规律,根据南海湖不同水域使用功能划分区域,于2017年12月在南海湖布设采样点取样,检测各采样点不同形态氮含量,ArcGIS软件分析湖泊中各种形态氮空间特异性.研究结果表明,包头南海湖氮污染物空间分布整体呈东高西低,由西南向东北呈逐渐增加趋势.总氮浓度为2.286～5.988 mg·L-1,氨氮浓度在1.049～3.436 mg·L-1,硝态氮在0.019～0.059 mg·L-1,亚硝态氮在0.016～0.069 mg·L-1,氨氮含量达总氮50％以上,硝态氮和亚硝态氮浓度较低.位于旅游开发区内湖心岛周围区域及出水口区总氮、氨氮及亚硝态氮浓度较高.总氮、氨氮及亚硝态氮空间分布趋于一致,硝态氮空间分布则与之相反.从研究数据分析结果可知,由于迁移浓缩效应,冰体中各种形态氮含量均小于水体中含量.研究可为南海湖冬季氮污染治理提供理论依据,为渔业保护提供技术支持.%In order to explore the spatial distribution characteristics and variation regularity of different forms of nitrogen in the frozen period of Baotou Nanhai Lake,the regional division was carried out according to the function of different water areas.Sampling points were sampled in December 2017,and the contents of different nitrogen forms were detected by laboratory.The spatial distribution characteristics were analyzed by ArcGIS software.The results showed that the spatial distribution of nitrogen pollutant in Baotou Nanhai Lake was a trend of increasing from southwest to northeast.The total nitrogen concentration was between 2.286-5.988 mg·L-1,ammonia nitrogen concentration was between 1.049-3.436 mg·L-1,nitrate nitrogen was between 0.019-0.059 mg· L-1,and nitrite nitrogen was between 0.016-0.069 mg· L-1.The content of ammonia nitrogen was higher than 50％ of the total nitrogen,while the concentrations of nitrate and nitrite nitrogen were low.The concentrations of the total nitrogen,ammonia and nitrite around the lake island which was located in the tourism development area was higher.The spatial distribution of the total nitrogen,ammonia nitrogen and nitrite were consistent,while the spatial distribution of nitrate nitrogen was opposite to them.From the results of data analysis,it could be seen that the contents of various forms of nitrogen in ice was smaller than that of water body because of the migration concentration effects.The research results could provide theoretical supports for nitrogen pollution control and provide technical supports for fisheries protection.