LIANG Yayu1, LI Lijun2, SONG Zhihui3, BAI Guangjie2, LV Wei2, LIU Ping2**
(1. School of Biological Engineering, Shanxi University, Taiyuan 030006, China;
2. Institute of Agricultural Environment and Resources, Shanxi Academy of Agricultural Sciences, Taiyuan 030031, China;
3. Monitoring Station of Xinghualing Branch Bureau of Taiyuan Environmental Protection Bureau, Taiyuan 030009, China)
Abstract: A research on temporal and spatial variation of atmospheric nitrogen wet deposition was conducted using the rain gauge method at the downtown, suburb and outer suburbs of the Taiyuan City from January 2016 to December 2017. The concentrations of NO3--N and NH4+-N averaged from1.3 mg/L to18.4 mg/L and from1.6 to 3.6 mg/L, respectively. The average concentrations of NH4+-N were stable in all seasons, but average concentrations of NO3--N were higher in winter and spring seasons. The annual averaged wet depositions of inorganic N(IN) were 40.0, 48.0, 14.2 kg/hm2, respectively, at three sampling sites (downtown, suburb and outer suburbs of Taiyuan). The wet deposition rates of NH4+-N were 9.0, 5.0, 8.2 kg/hm2 and accounted for 22%, 11%, 57% of the IN depositions, while wet deposition rates of NO3--N were 31.0, 43.0, 6.0 kg/hm2 and accounted for 78%, 89%, 43% of IN depositions at three sampling sites, respectively. The average concentration ratios of NH4+-N/NO3--N were 0.54, 0.30 and 1.31, respectively, at three sites. In addition, the difference between nitrogen wet deposition and rainfall in the downtown and suburban areas was not significant but reached a very significant level at outer suburbs, indicating that affecting factors of wet deposition at urban areas are more complicated than at the outer suburbs. These results might suggest that atmospheric nitrogen wet depositions were affected mainly by industry or/and transportation at downtown and suburb, while by agriculture activities at outer suburbs. In summary, to prevent high wet depositions of N in the Taiyuan area, different strategies should be applied according to different sites.
Key words:city center;near suburb;far suburb;wet N deposition;NH4+-N and NO3--N;correlation
EARTH AND ENVIRONMENT Vol.47, No.4, Tot No.330, 2019, Page 405-411