丹江口库区大气氮干湿沉降动态变化特征研究

Dynamic characteristics of atmospheric nitrogen dry and wet deposition in Danjiangkou Reservoir area

大气环境中高氮以干/湿沉降的方式返回地表,进入陆地生态系统和水生生态系统可能引起一系列负面生态效应。以丹江口库区为研究对象,基于2016~2018年的大气氮干湿沉降连续监测数据,研究了丹江口库区大气氮沉降的动态变化特征。结果表明:(1)2016~2018年,丹江口库区大气湿沉降中TN、AN、NN、DN通量分别为29.48,10.75,11.27,24.52 kg/(hm^(2)·a),其中,夏季TN、AN、NN和DN湿沉降通量最高,分别占全年各形态氮湿沉降总量的32.85%,43.94%,26.74%,33.59%。(2)库区TN、AN、NN和DN干沉降通量分别为8.38,1.56,1.26,5.77 kg/(hm^(2)·a),从季节分配上呈现冬季>秋季>春季>夏季的特点。(3)2016~2018年库区大气总氮沉降量为37.86 kg/(hm^(2)·a),其中,TN干、湿沉降通量分别占总沉降量的22.13%和77.87%。丹江口库区大气氮沉降过程与通量研究,可更好地揭示大气氮沉降对库区水体养分的输入贡献,丰富库区水体“营养源”的解析,为加强库区氮素管理,降低库区水体富营养化风险提供依据。

Nitrogen in the atmospheric environment caused by human activities returns to terrestrial and aquatic ecosystems in a form of dry/wet deposition,which may causes a series of negative ecosystem effects.This paper studied the dynamic characteristics of atmospheric nitrogen deposition in the Danjiangkou Reservoir area based on the continuous monitoring data of atmospheric dry and wet nitrogen deposition from 2016 to 2018.The results indicated that:(1)The average annual fluxes of TN,AN,NN,and DN in atmospheric wet deposition from 2016 to 2018 were 29.48,10.75,11.27,and 24.52 kg/(hm^(2)·a),and the wet deposition fluxes of TN,AN,NN and DN were the highest in summer,accounting for 32.85%,43.94%,26.74%,33.59%of the total wet deposition fluxes of different forms,respectively.(2)The dry deposition fluxes of TN,AN,NN,and DN were 8.38,1.56,1.26,5.77 kg/(hm^(2)·a)respectively,and had the following temporal orders:winter>autumn>spring>summer.(3)From 2016 to 2018,the total atmospheric nitrogen deposition in the reservoir area was 37.86 kg/(hm^(2)·a).Among them,the TN dry and wet deposition fluxes accounted for 22.13%and 77.87%of the total deposition,respectively.The study of atmospheric nitrogen deposition process and flux can better reveal the contribution of atmospheric nitrogen deposition to the input of nutrients in the reservoir area,enrich the understanding of the“nutrient source”of water body in the Danjiangkou Reservoir,and also fundamentally strengthen nitrogen management in the reservoir area.