浑河上游清原流域河流氮素污染时空变异及其与土地利用的关系

Spatial and Temporal Variation of Nitrogen Pollution and Its Relationship With Land Use in Qingyuan Watershed of Upper Hunhe River

以浑河上游清原流域为研究区,通过河流现场采样、实验室测试分析获得水质数据,采用遥感信息处理和地理信息系统平台获得土地利用数据,运用数理统计和空间统计的方法分析总氮、硝态氮和氨氮污染程度以及土地利用特征,并探讨了河流氮素污染时空变异与土地利用的关系,得出以下结论:地表水总氮和氨氮超标率较高,总氮和硝态氮污染处于偏高的程度,氨氮污染处于中等偏低程度;总氮与硝态氮的质量浓度在枯水期最大,丰水期最小,氨氮质量浓度在丰水期最大,秋季平水期最小;氮素污染程度从上游至下游逐渐加重,氮素空间变异性与人为活动强度梯度相对应;河流氮素主要来源于旱田、城镇和农村建设用地、畜禽养殖集中区,林地面积占比的增加有利于削减氮素污染程度;规划和实践非点源污染最佳管理措施(BMPs)是实现该水源保护区或其他地区类似流域地表水环境氮素污染削减的有效途径之一.

The Qingyuan river watershed in the upper reaches of Hunhe River was taken as the research area.Water quality data were obtained through field sampling,laboratory testing and analysis.Land use data were obtained by remote sensing information processing and GIS.The pollution degree of total nitrogen(TN),nitrate nitrogen(NO3-N)and ammonia nitrogen(NH4-N)and land use features were analyzed by mathematical statistics of SPSS and spatial statistics of GIS.The relationship between nitrogen pollution and land use was discussed.The main conclusions are shown:total nitrogen and ammonia nitrogen in surface water far exceed the limit value of the second water index of surface water,the content of nitrate nitrogen in water is also higher,but ammonia nitrogen content is lower than other water resource protect area in China;the concentration of total nitrogen and nitrate nitrogen is the largest in dry season and the smallest in flood season.The concentration of ammonia nitrogen was the highest in the flood season and the lowest in the autumn season;the level of nitrogen pollution gradually increased from upstream to downstream,and the spatial variability of nitrogen corresponded to the gradient of human activity intensity;nitrogen in rivers mainly came from dry land,urban and rural construction land,concentrated livestock and poultry farming areas,and the level of nitrogen pollution descended with increase of the proportion of forest land;planning and practicing the best management measures(BMPs)for non-point source pollution is one of the effective ways to reduce surface water nitrogen pollution in this water source protection area or other similar watersheds.