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Environmental Protection Agency GeoSEM Overview  

GeoSEM is a geographic information system (GIS)-based program for incorporating spatial statistics in human health and ecological exposure assessment. With GeoSEM, the user can evaluate the spatial information contained in analytical data by comparing the results obtained using classical "non-spatial" statistical methods with the results obtained using one of the three spatial methods available in GeoSEM: spatial weighting, kriging, and simulation. The results can be used to estimate exposure point concentrations at the site.


GeoSEM Home Site
  • Visualization
  • Statistical Analysis
  • Geospatial Interpolation
  • Input
  • Tabular File: *.xls, *.mdb
  • Graphical File: DOD vector product format (VPF) ,   ESRI product files, CAD drawings (dxf), ASCI II   grids, and georeferenced image formats such as   geoTIFs, bitmaps, GIFs, JPGs, and ERDAS.
  • Output
    • Tabular File: *.dbf
    • Graphical File: *.shp
    • Print Report: No
    • Metals
    • Chlorinated Solvents
    • SVOCs
    • Pesticides/PCBs
    • Petroleum
    • Radionuclides
    • Soil Sediment
    • Soil Gas
    • Air
    • Surface Water
    • Groundwater
    Technical Team Members
    • Risk Assessor
    • Statistician
    GeoSEM - data loading
    • Tabular data can be entered as Microsoft Excel files or Microsoft Access format, but the column headings must follow a specific format.
    GeoSEM - graphic loading
    • GeoSEM uses several geographic information system (GIS) vector and raster file formats, including DOD vector product format (VPF), ESRI product files, CAD drawings (dxf), ASCI II grids, and georeferenced image formats such as geoTIFs, bitmaps, gif, jpg, and ERDAS.
    GeoSEM - logical flow
    • Functionality follows ESRI's MapObjects 2.0. Menus along the top of screen are arranged to follow logical flow from left to right. Some buttons are grayed out until the user completes the necessary precursor steps.
    GeoSEM - expert knowledge
    • This DST is designed for use by risk assessors. Other team members may include a statistician to assist with specific parameters of various statistical methods, applications, and interpretation. The graphical interface is GIS based; although it is user-friendly, knowledge of ESRI software is helpful, so a GIS technician could assist.
    GeoSEM - documentation
    • Users manual has clear layout, including sections on Installation and a "Quick Start to Using GeoSEM" section that provides a demonstration of the software using data provided with the program. The users manual is cursory, providing information on specific buttons and menus. Several appendices are provided in the Users Manual.
    • Section 8.0 - Release Notes - provides important information such as an interpretation of common error messages and discussion of "bugs" that may interfere with using the software. The user should review this section before working with the software.
    • Appendix A provides the abbreviations used in GeoSEM output.
    • Appendix B provides a brief discussion of map projections and datums.
    • Appendix C provides a brief overview of geostatistics.
    • Appendix D provides equations used in GeoSEM functions.
    • There are no Help menus.
    GeoSEM - output
    • Graphical results are output in shp files. Tabular data are output as dbf files.
    GeoSEM - sources
    • Version 2.0a (October 2004) downloaded December 14, 2004.
    • Users Manual Version 5.0.
    • Mr. Bill Thayer, one of the developers of the DST, with Syracuse Research Corporation (SRC) was contacted several times to discuss issues the evaluator was having with the DST during the week of January 10, 2005.
    Note that this DST matrix is under active construction. Comments and suggestions about the structure
    or content of this website should be sent to Mike Adam .
    This web site contains technology information from private contractors and government agencies and is for informational purposes only. EPA cannot guarantee the accuracy or completeness of the data. Reference to any specific commercial product, process, or service, by trade name, trademark, manufacturer, or otherwise, does not constitute or imply the endorsement, recommendation, or favor of the United States Government.