Elemental Analysis of Soil Phosphorus Neighborhoods Using SEM, Spectral Mapping and GIS  

作　　者：Kathleen M. Baker Asmare Atalay Carol Bronick Brodie Whitehead 

机构地区：[1]Department of Geography, Western Michigan University, Kalamazoo 49008, US [2]Agricultural Research Station, Virginia State University, Petersburg 23806, US [3]Formerly Post-Doctoral Associate at ~Trginia State University, Petersburg 23806, US

出　　处：《Journal of Environmental Science and Engineering(A)》2013年第8期494-505,共12页环境科学与工程（A）

摘　　要：The utility of GIS （geographic information system） methods and spatial statistical analysis on spectral maps of sediment samples were examined. Detailed elemental maps are often constructed using energy dispersive X-ray techniques and SEM （scanning electron microscopy）. The elemental neighborhood associations of a single element, P （phosphorus）, were quantified at a magnification of 3,000 ×. For each of the 170,000 pixels on the images which displayed a strong P concentration, neighborhoods from 0.1μm^2 to 12 μm^2 were examined for associated elemental concentrations. PCA （principal component analysis） revealed two significant neighborhood types associated with P in samples of pH 4, and three neighborhood types at pH 8. These neighborhoods corresponded to Mg-P associations commonly found to be chemically prevalent in river sediments impacted by agricultural operations. Discriminant analysis showed that the greatest accuracy in predicting sample pH could be achieved by using a neighborhood size of 12 ~m2. Potassium at relatively large neighborhood sizes was the element most significant in predicting pH. While many of the chemical associations in close proximity to P could be predicted and explained through mineral solubility, spatial analysis provided some interesting insights into the structure of the samples. Results also indicted differences in the spatial scale associated with different processes.

关 键 词：SEM （scanning electron microscopy） geographic information systems energy dispersive X-ray analysis principalcomponents analysis spatial analysis soil chemistry. 

分 类 号：P208[天文地球—地图制图学与地理信息工程] TQ533.1[天文地球—测绘科学与技术]