摘要
大气氮磷干沉降是湖泊外源营养盐输入的重要途径之一,对湖泊水体富营养化及生态系统演化具有重大影响。文章为了深入揭示洱海湖区大气氮磷干沉降(颗粒物)对水体的贡献,于2021年全年对洱海周边布设的6个站点进行了为期1 a的大气干沉降连续监测,使用自动降尘采样器湿法收集大气干沉降。分析了洱海湖区氮磷干沉降通量的时空分布特征,估算了氮磷干沉降直接入湖负荷量。结果表明:洱海湖区干沉降(颗粒物)TN、TP沉降通量年内总体呈先降后升再降的趋势。TN沉降通量范围为8.78~84.93 kg/km^(2),均值为(33.44±15.94)kg/km^(2);TP沉降通量范围为0.38~11.91 kg/km^(2),均值为(4.04±2.69)kg/km^(2);2021年洱海湖区干沉降TN、TP直接入湖负荷量分别为107.69 t和13.28 t,TN、TP干沉降直接入湖负荷量约占流域农业面源排放量的3.91%和5.12%;影响洱海湖区TN、TP干沉降的主要因素包括湖区上空低层风场环流、湖区降雨分布、气溶胶粒径以及小流域下垫面土地利用现状。
Atmospheric nitrogen and phosphorus dry deposition is one of the important ways for lake exogenous nutrient input,which has a significant impact on lake water eutrophication and ecosystem evolution.In order to further reveal the contribution of atmospheric nitrogen and phosphorus dry deposition(particulate matter)to the water body in Erhai Lake area,continuous monitoring of atmospheric dry deposition was carried out for 1 year at 6 stations around Erhai Lake in 2021,and automatic dust sampling device was used to collect wet method.Atmospheric dry deposition,the temporal and spatial distribution characteristics of nitrogen and phosphorus dry deposition flux in the Lake area were analyzed,and the direct load of nitrogen and phosphorus dry deposition into the lake was estimated.The results showed that the dry deposition(particulate matter)TN and TP deposition fluxes in the Lake area generally showed a trend of first decreasing,then increasing and then decreasing during the year.The TN sedimentation flux ranged from 8.78 to 84.93 kg/km^(2),with an average value of(33.44±15.94)kg/km^(2);the TP sedimentation flux ranged from 0.38 to 11.91 kg/km^(2),with an average value of(4.04±2.69)kg/km^(2).The direct load of TN and TP into the lake by dry deposition in 2021 was 107.69 t and 13.28 t respectively,and the load of TN and TP directly into the lake by dry deposition accounted for about 3.91%and 5.12%of the agricultural non-point source emissions in the basin;The main factors affecting the dry deposition of TN and TP in the Erhai Lake area include low-level wind circulation over the lake area,rainfall distribution in the lake area,aerosol particle size,and land use status of the underlying surface of the small watershed.
作者
黄明雨
HUANG Mingyu(Dali Erhai Lake Research Institute,Dali 671000,China)
出处
《环境科学与技术》
CAS
CSCD
北大核心
2023年第1期33-38,共6页
Environmental Science & Technology
基金
大理州州财政项目(2019532900000519)
关键词
洱海
干沉降
氮磷
通量
时空分布
入湖负荷
Erhai Lake
dry deposition
nitrogen and phosphorus
flux
temporal and spatial distribution
load into the lake
