title: Influencing factor analysis of phosphorus loads from non-point source: a case study in central China.
abstract: The influence factor analysis for non-point source (NPS) pollution is very important to taking effective water pollution control measures. In this study, the self-organizing map (SOM) and linear model analysis were used to analyze the relationships between total phosphorus (TP) loads and influencing factors, both qualitatively and quantitatively. The land-use type, topography, and vegetation coverage were the main factors influencing the export of TP loads in Tangxun watershed. Slope and normalized difference vegetation index (NDVI) were chosen as characteristic indices of topography and vegetation coverage, respectively. For the whole watershed, the high TP loads were mainly distributed in areas with high slope and low vegetation coverage for a specific land-use type. For different land types, the slope significantly influenced the export of TP loads in waste/bare land and forest/green land while NDVI influenced the export of TP loads in forest/green land and farmland. In terms of multi-factor analysis, the comprehensive influence of slope and NDVI on TP loads showed as waste/bare land>forest/green land>farmland>rural/urban construction land.
authors.affiliation: Key Laboratory of Environment and Disaster Monitoring and Evaluation of Hubei, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan, 430077, China.
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Zhuang
authors.affiliation: School of Resource and Environmental Science, Wuhan University, Wuhan, 430079, China. songhongpku@126.com.|Department of Geography, Texas State University, San Marcos, TX, 78666, USA. songhongpku@126.com.
authors.forename: Song
authors.initials: S
authors.lastname: Hong
authors.affiliation: Department of Geography, Texas State University, San Marcos, TX, 78666, USA.
authors.forename: F Benjamin
authors.initials: FB
authors.lastname: Zhan
authors.affiliation: Key Laboratory of Environment and Disaster Monitoring and Evaluation of Hubei, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan, 430077, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhang
mesh_terms: D002681:China; D004784:Environmental Monitoring; D005163:Factor Analysis, Statistical; D009584:Nitrogen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis*; D045483:Rivers; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D010758:Phosphorus; D009584:Nitrogen
keywords: Complex non-point source; Influence factors; Phosphorus; Self-organizing map (SOM); Urban-rural fringe