Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu 610065, Sichuan, China.
Department of Environment, College of Architecture and Environment, Sichuan University, Chengdu 610065, Sichuan, China; Jiuzhaigou Administrative Bureau, Zhangzha Town, Jiuzhaigou County 623402, Sichuan, China.
Environ Pollut. 2018 Feb;233:267-277. doi: 10.1016/j.envpol.2017.08.041. Epub 2017 Nov 5.
In order to understand the impacts of regional emission changes and local tourism on sulfur and nitrogen wet deposition in Jiuzhaigou National Nature Reserve of southwestern China, wet deposition was monitored at a background site (Rize) and a tourist-affected site (PE: park entrance) in the reserve during 2015-2016. The observation data were compared between Rize and PE and between 2010-2011 and 2015-2016 monitoring campaigns. Also, the observation data were used in the Positive Matrix Factorization (PMF) model to identify the major sources of sulfur and nitrogen wet deposition. The results show that although local tourism emissions had considerable contributions to NH, NO, NO, and SO concentrations in wet deposition (p < 0.05), most of the annual Volume Weighted Mean (VWM) concentrations of these four ions were likely from emissions outside Jiuzhaigou. Annual wet deposition fluxes of the four ions were also affected more by precipitation and regional emissions than by local emissions. Although annual precipitation was higher at Rize (818 mm) during 2015-2016 than at another background site near Long Lake (LL: 752 mm) during 2010-2011, the annual concentrations and fluxes of SO and NO wet deposition decreased by 77% and 74% for SO and by 12% and 19% for NO, respectively, most likely due to regional emission reductions. Similar large reductions in SO and NO concentrations have been also found in some other sites in southwestern China. In contrast, the annual concentration and flux of NH wet deposition at Rize during 2015-2016 were 1.4 and 1.2 times of that measured at LL during 2010-2011, respectively. The results of source apportionment analysis and tour bus emission estimates suggest that elevated NH wet deposition was possibly related to NH emissions from local tour buses, but additional studies on NH emissions from tour buses in the reserve are needed to confirm this.
为了了解区域排放变化和当地旅游业对中国西南九寨沟国家自然保护区硫和氮湿沉降的影响，在 2015-2016 年期间，在保护区的背景站点（日则）和受游客影响的站点（PE：公园入口）监测了湿沉降。比较了日则和 PE 站点之间以及 2010-2011 年和 2015-2016 年监测期间的观测数据。此外，还将观测数据应用于正定矩阵因子分解（PMF）模型，以确定硫和氮湿沉降的主要来源。结果表明，尽管当地旅游业排放对湿沉降中 NH、NO、NO 和 SO 浓度有相当大的贡献（p<0.05），但这四种离子的年体积加权平均值（VWM）浓度主要来自九寨沟以外的排放源。这四种离子的年湿沉降通量也更多地受到降水和区域排放的影响，而不是受到当地排放的影响。尽管 2015-2016 年日则的年降水量（818mm）高于 2010-2011 年另一个靠近长海（LL）的背景站点（752mm），但 SO 和 NO 的年湿沉降浓度和通量分别下降了 77%和 74%，SO 下降了 12%和 19%，这很可能是由于区域减排。在中国西南地区的其他一些地区也发现了类似的 SO 和 NO 浓度大幅下降的情况。相比之下，2015-2016 年日则的年 NH 湿沉降浓度和通量分别是 2010-2011 年 LL 站点的 1.4 和 1.2 倍。来源解析分析和旅游巴士排放估算的结果表明，NH 湿沉降的增加可能与当地旅游巴士排放的 NH 有关，但需要对保护区内旅游巴士的 NH 排放进行更多的研究来证实这一点。
