岗南水库上游流域大气氮干湿沉降研究

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 171 7~ 1341 7 kg / ( km2 # 月) 和 91 9~ 3861 8 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 1051 16 t/ a。 In this study , w e chose fiv e sam pling points in Gangnan reserv oir basin to m onitor nitro gen depo sitions. We analyzed the spatial and t em po ral distributio n characteristics o f dr y and w et depo sition fluxes o f atm ospheric nit rog en fr om July 2015 to June 2016. T he r esults show ed that dry and w et depositio n flux es of to tal nitr og en wer e 171 721341 7 kg/ ( km 2 # month) and 91 923861 8 kg/ ( km2 # m onth) r espectively. The nitr ate and or ganic nit rog en w ere the dominant contributors to atmo spheric dr y depositio n flux . Their amount w as hig her in spring and summer. The nitr og en form s in w et depositio n w ere m ainly amm onia nitro g en and nitr ate nitro g en, the am ount of w hich w as hig her in sum mer and spring and low er in fall and w inter. In t erms of spat ial dist ribution, ther e w as an increasing tr end f rom the northw est to the so utheast. Based o n the t otal amo unt o f atm os2 pheric nitro g en deposit ion, w at ershed ar ea, and r eserv oir surface area, w e calculated the tota l atmo spheric nitr og en depositio n into riv er fo r the w hole ba sin, w hich w as 3 674 t/ a. The dir ect nitr og en depo sition into the Gang nan reser vo ir w as 1 051 16 t/ a