title: Water quality variation in the highly disturbed Huai River Basin, China from 1994 to 2005 by multi-statistical analyses.
abstract: Water quality deterioration is a prominent issue threatening water security throughout the world. Huai River Basin, as the sixth largest basin in China, is facing the most severe water pollution and high disturbance. Statistical detection of water quality trends and identification of human interferences are significant for sustainable water quality management. Three key water quality elements (ammonium nitrogen: NH3-N, permanganate index: CODMn and dissolved oxygen: DO) at 18 monitoring stations were selected to analyze their spatio-temporal variations in the highly disturbed Huai River Basin using seasonal Mann-Kendall test and Moran's I method. Relationship between surrounding water environment and anthropogenic activities (point source emission, land use) was investigated by regression analysis. The results indicated that water environment was significantly improved on the whole from 1994 to 2005. CODMn and NH3-N concentrations decreased at half of the stations, and DO concentration increased significantly at 39% (7/18) stations. The high pollution cluster centers for both NH3-N and CODMn were in the middle stream of Shaying River and Guo River in the 2000s. Water quality of Huai River Basin was mainly influenced by point source pollution emission, flows regulated by dams, water temperature and land use variations and so on. This study was expected to provide insights into water quality evolution and foundations for water quality management in Huai River Basin, and scientific references for the implementation of water pollution prevention in China.
authors.affiliation: State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhai
authors.affiliation: State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China. Electronic address: xiaj@igsnrr.ac.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Xia
authors.affiliation: Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Science and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Yongyong
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D002681:China; D004784:Environmental Monitoring; D012044:Regression Analysis; D045483:Rivers / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014876:Water Pollution / Q000706:statistics & numerical data*; D060753:Water Quality
chemical_list: D014874:Water Pollutants, Chemical
keywords: Huai River Basin; Moran's I; Regression analysis; Seasonal Mann–Kendall; Water quality trends