title: Assessment of water quality and identification of polluted risky regions based on field observations & GIS in the Honghe River watershed, China.
abstract: Water quality assessment at the watershed scale requires not only an investigation of water pollution and the recognition of main pollution factors, but also the identification of polluted risky regions resulted in polluted surrounding river sections. To realize this objective, we collected water samplings from 67 sampling sites in the Honghe River watershed of China with Grid GIS method to analyze six parameters including dissolved oxygen (DO), ammonia nitrogen (NH3-N), nitrate nitrogen (NO3-N), nitrite nitrogen (NO2-N), total nitrogen (TN) and total phosphorus (TP). Single factor pollution index and comprehensive pollution index were adopted to explore main water pollutants and evaluate water quality pollution level. Based on two evaluate methods, Geo-statistical analysis and Geographical Information System (GIS) were used to visualize the spatial pollution characteristics and identifying potential polluted risky regions. The results indicated that the general water quality in the watershed has been exposed to various pollutants, in which TP, NO2-N and TN were the main pollutants and seriously exceeded the standard of Category III. The zones of TP, TN, DO, NO2-N and NH3-N pollution covered 99.07%, 62.22%, 59.72%, 37.34% and 13.82% of the watershed respectively, and they were from medium to serious polluted. 83.27% of the watershed in total was polluted by comprehensive pollutants. These conclusions may provide useful and effective information for watershed water pollution control and management.
authors.affiliation: State Key Laboratory of Pollution Control & Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, P. R. China; Kunming Institute of Environmental Science, Kunming 650032, P.R. China.
authors.forename: Chang-An
authors.initials: CA
authors.lastname: Yan
authors.affiliation: Key Laboratory of Digital Earth Science, Institute of Remote Sensing and Digital Earth (RADI), Chinese Academy of Sciences (CAS), Beijing 100094, P. R. China.
authors.forename: Wanchang
authors.initials: W
authors.lastname: Zhang
authors.affiliation: College of Automation, Nanjing University of Posts and Telecommunications, Nanjing 210093, P.R. China.
authors.forename: Zhijie
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Pollution Control & Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, P. R. China; Key Laboratory of Digital Earth Science, Institute of Remote Sensing and Digital Earth (RADI), Chinese Academy of Sciences (CAS), Beijing 100094, P. R. China.
authors.forename: Yuanmin
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Pollution Control & Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, P. R. China; Key Laboratory of Digital Earth Science, Institute of Remote Sensing and Digital Earth (RADI), Chinese Academy of Sciences (CAS), Beijing 100094, P. R. China.
authors.forename: Cai
authors.initials: C
authors.lastname: Deng
authors.affiliation: State Key Laboratory of Pollution Control & Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, P. R. China; Key Laboratory of Digital Earth Science, Institute of Remote Sensing and Digital Earth (RADI), Chinese Academy of Sciences (CAS), Beijing 100094, P. R. China.
authors.forename: Ning
authors.initials: N
authors.lastname: Nie
mesh_terms: D002681:China; D003247:Conservation of Natural Resources / Q000379:methods; D004784:Environmental Monitoring / Q000379:methods; D040362:Geographic Information Systems; D015386:Hazardous Substances / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D010758:Phosphorus / Q000737:chemistry; D045483:Rivers / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry; D014876:Water Pollution / Q000032:analysis*; D060753:Water Quality
chemical_list: D015386:Hazardous Substances; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D009584:Nitrogen; D010100:Oxygen