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岗南水库上游流域大气氮干湿沉降研究

2018-12-29赵宪伟李橙杨晶马雄飞王月锋吴亦红田在锋

南水北调与水利科技 2018年5期

赵宪伟 李橙 杨晶 马雄飞 王月锋 吴亦红 田在锋

摘要:以岗南水库上游流域为研究对象,在岗南水库及其控制流域设置5个采样点位,分析2015年7月至2016年6月流域大气氮素干、湿沉降通量时空分布特征。结果表明,岗南水库流域总氮干、湿沉降通量范围分别为177~1347 kg/(km2·月)和99~3868 kg/(km2·月)。大气干沉降以硝态氮和有机氮为主,春、夏季较高;湿沉降中氮素形态以氨态氮和硝态氮为主,夏季最高,春季次高,秋冬季较低。空间分布上,呈现出由西北向东南不断增加的趋势。利用大气氮素总沉降量、流域面积以及水库水面面积计算得到全流域大气总氮沉降入河负荷量为3 674 t/a,直接沉降入库负荷量为10516 t/a。

关键词:岗南水库;氮;干沉降;湿沉降

中图分类号:X52 文献标志码:A 文章编号:

16721683(2018)05011507

Dry and wet deposition of nitrogen in the upstream basin of Gangnan Reservoir

ZHAO Xianwei1,LI Cheng2,3,YANG Jing2,3,MA Xiongfei2,3,WANG Yuefeng2,3,WU Yihong2,TIAN Zaifeng2

(

1.College of Water Sciences,Beijng Normal University,Beijing 100875,China;2.Hebei Academy of Environmental Sciences,Shijiazhuang 050037,China;3.Zhengqi Environmental Technology Co Ltd of Hebei,Shijiazhuang 050037,China)

Abstract:

[JP+2]In this study,we chose five sampling points in Gangnan reservoir basin to monitor nitrogen depositions.We analyzed the spatial and temporal distribution characteristics of dry and wet deposition fluxes of atmospheric nitrogen from July 2015 to June 2016.The results showed that dry and wet deposition fluxes of total nitrogen were 1771347 kg/(km2·month) and 993868 kg/(km2·month) respectively.The nitrate and organic nitrogen were the dominant contributors to atmospheric dry deposition flux.Their amount was higher in spring and summer.The nitrogen forms in wet deposition were mainly [JP+3]ammonia nitrogen and nitrate nitrogen,the amount of which was higher in summer and spring and lower in fall and winter.In terms of spatial distribution,there was an increasing trend from the northwest to the southeast.Based on the total amount of atmospheric nitrogen deposition,watershed area,and reservoir surface area,we calculated the total atmospheric nitrogen deposition into river for the whole basin,which was 3 674 t/a.The direct nitrogen deposition into the Gangnan reservoir was 10516 t/a.

Key words:

Gangnan Reservoir;nitrogen;dry deposition;wet deposition

氮素循環是自然界中重要的物质循环之一,20世纪以来,全球人口迅速增长,过量施用合成化肥以及畜禽养殖的发展,使得地球生态系统氮负荷超载,大气中含氮物质的浓度快速增加,最终过量的氮通过大气沉降进入水体和土壤。研究表明,55%~60%的人为活性氮以NOx和NHy这两种形式释放到大气中,其中70%~80%的成分继而又以大气干、湿沉降的方式返回到陆地系统和水体[12]。过量的氮沉降会引发土壤酸化、水生态系统富营养化等负面效应[34]。发达国家开展大气沉降的研究较早,目前主要集中在网络化、系统化方向,应用模型模拟不同生态系统的氮沉降量和沉降负荷[5]。中国氮沉降研究起步于20世纪70年代[6]。近些年的研究主要集中在不同生态系统大气氮素沉降的时空分布规律及影响方面[710]。……

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