摘要
城市河流是重要的N_(2)O和CH_(4)排放源,受到环境条件和监测方法的影响,不同地区城市河流的温室气体排放能力差异明显。为确定典型城市河流水-气界面N_(2)O和CH_(4)排放速率及其影响因素,选择典型城市河流新乡市卫河作为研究对象,同时利用漂浮静态箱法和扩散模型法监测河流温室气体排放通量,并对监测结果进行对比分析。研究结果表明卫河新乡段表现为N_(2)O和CH_(4)的持续排放源,其中N_(2)O的溶存和排放与硝态氮(P<0.01)、铵态氮(P<0.01)、溶解有机碳(P<0.01)和氧化还原电位(P<0.05)均具有显著相关性,气温(P<0.05)、溶解无机碳(P<0.05)与N_(2)O排放显著相关;CH_(4)溶存量与溶解无机碳(P<0.01)、ORP(P<0.05)显著相关,而影响CH_(4)排放的主要因子为水温(P<0.01)和氧化还原电位(P<0.01)。扩散模型法获得的N_(2)O和CH_(4)排放速率日均值分别为是漂浮静态箱法的59.15%、68.74%,不同方法获得的水体温室气体排放速率显著相关(P<0.01),说明扩散模型法对较浅以及流速平缓的城市河流具有一定适用性。扩散模型法获得的排放速率日均值分别为静态箱法的59.15%(N_(2)O)和68.74%(CH_(4)),反映了春季卫河中CH_(4)的冒泡排放贡献较低,而N_(2)O可能具有较高的冒泡排放通量。
As significant source of greenhouse gases,urban river has wide ranges of N_(2)O and CH_(4)emission rates because of various environmental conditions and different monitoring methods.A typical unban river,the Wei River in Xinxiang City,was selected to monitor the emission rates of N_(2)O and CH_(4)at the river water—air interface in spring.Both the floating static chamber method and the diffusion model method were applied to conduct the experiment,and comparison between their results was carried out.The influences of water quality and other environmental factors on the emission rates were also analyzed.The results showed that the Wei River behaved as continued source of N_(2)O and CH_(4),and both the concentrations and the emission rates of N_(2)O were significantly related to nitrate(P<0.01),ammonia(P<0.01),dissolved organic carbon(P<0.01)and redox potential(P<0.05),and the air temperature and dissolved inorganic carbon were only related to N_(2)O emission rates(P<0.05).The concentrations of CH_(4)were significantly correlated to dissolved organic carbon(P<0.01)and redox potential(P<0.05),while CH_(4)emission rates were significantly correlated to water temperature(P<0.01)and redox potential(P<0.01).The average daily emission rates of N_(2)O and CH_(4)obtained by the diffusion model method were 59.15%and 68%of those measured using the floating static chamber method,respectively.Moreover,the emission rates of the gases calculated from the two methods were significantly correlated(P<0.01),demonstrating that the diffusion model method is suitable for shallow and slow urban rivers.The daily average emission rates obtained by the diffusion model method were 59.15%(N_(2)O)and 68.74%(CH_(4))of the static box method,respectively,reflecting that the contribution of CH_(4)bubbling emission in the Wei River was low in spring,while N_(2)O may have a higher bubbling emission flux.
作者
艾年志
张鸿莉
刘恒
侯翠翠
李书粉
AI Nianzhi;ZHANG Hongli;LIU Heng;HOU Cuicui;LI Shufen(College of Life Science,Henan Normal University,Xinxiang 453000,China)
出处
《华南地理学报》
2025年第3期42-53,共12页
South China Geographical Journal
基金
河南省自然科学基金项目(252300420289)。
