title: Surface water pH variations and trends in China from 2004 to 2014.
abstract: With economic development and the increase of energy consumption, surface water acidification has been a potential environmental concern in China. Here, we analyzed variations and trends in surface water pH of 73 sites from ten river basins in China from 2004 to 2014 with nonparametric Seasonal Kendall test method. Our analysis showed that the variations of surface water pH in China ranged from 6.5 to 9.0 in the past decade (2004-2014), which satisfied the water quality criteria in pH for protection of aquatic ecosystems in China (6.0-9.0) and USA (6.5-9.0). However, significant decreasing trends in surface water pH were found in 31 monitoring sites, which were mainly located in Haihe River, Taihu Lake and Yangtze River, while the pH value showed significant increasing trends in 22 sites, which mainly were located in Songhua River and Pearl River. Our results suggested the increased potential acidification of susceptible water bodies in China. Besides the control policy of sulfur dioxide (SO2) emissions, the emissions of nitrous oxides (NOx) should also be reduced to protect the aquatic systems in China.
authors.affiliation: Key Laboratory of Pollution Process and Environmental Criteria of Ministry of Education and Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China.
authors.forename: Yinhuan
authors.initials: Y
authors.lastname: Qiao
authors.affiliation: Key Laboratory of Pollution Process and Environmental Criteria of Ministry of Education and Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China. fengjf@nankai.edu.cn.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Feng
authors.affiliation: Key Laboratory of Pollution Process and Environmental Criteria of Ministry of Education and Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Liu
authors.affiliation: Bureau of Hydrology and Water Resources of Henan Province, Zhenzhou, 450003, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Bureau of Hydrology and Water Resources of Henan Province, Zhenzhou, 450003, China.
authors.forename: Pei
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Pollution Process and Environmental Criteria of Ministry of Education and Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhu
mesh_terms: D002681:China; D004784:Environmental Monitoring / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D060106:Lakes / Q000737:chemistry*; D045483:Rivers / Q000737:chemistry*; D013458:Sulfur Dioxide / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*; D060753:Water Quality
chemical_list: D014874:Water Pollutants, Chemical; D013458:Sulfur Dioxide
keywords: Acidification; Seasonal Mann–Kendall; Space distribution; Surface water; pH