Robert T. Pack
    Civil and Environmental Engineering
    Utah State University
    Logan, Utah 84322-4110
    robert<at symbol>
    David Tarboton
    Civil and Environmental Engineering, Utah Water Research Laboratory
    Utah State University
    Logan, Ut 84322-8200
    david.tarboton<at symbol>
    Craig N. Goodwin 
    Aquatic, Watershed and Earth Resources 
    Utah State University 
    Logan, Utah 84322-5230 

    SINMAP (Stability Index MAPping) is an ArcView extension that implements the computation and mapping of a slope stability index based upon geographic information, primarily digital elevation data.  SINMAP has its theoretical basis in the infinite plane slope stability model with wetness (pore pressures) obtained from a topographically based steady state model of hydrology.  Digital elevation model (DEM) methods are used to obtain the necessary input information (slope and specific catchment area). Parameters are allowed to be uncertain following uniform distributions between specified limits.  These may be adjusted (and calibrated) for geographic “calibration regions” based upon soil, vegetation or geologic data.  The methodology includes an interactive visual calibration that adjusts parameters while referring to observed landslides.  The calibration involves adjustment of parameters so that the stability map “captures” a high proportion of observed landslides in regions with low stability index, while minimizing the extent of low stability regions and consequent alienation of terrain to regions where landslides have not been observed.  This calibration is done while simultaneously referring to the stability index map, a specific catchment area and slope plot (of landslide and non landslide points) where lines distinguish the zones categorized into the different stability classes and a table giving summary statistics.

    This version of SINMAP was developed for the Windows NT and Windows 95 operating systems and ArcView 3.x.  It utilizes the ArcView geographic information system (GIS) from Environmental Systems Research Institute, Inc. (ESRI) for its standard GIS functionality and requires the following versions (or higher) of:

    Source code is also included for those who may not have these products or want to try implement the system on a different system.

    SINMAP2 was developed for ArcGIS 9.x. MW SINMAP V1.1 was developed by Enrico Chiaradia for MapWindow.

    Translations: Swedish


    The distribution comprises the following:  (1600KB) All inclusive zip file.  Click here and get the whole package, or explore individual pieces below.  (84KB) A zip file with only the program files sinmap.avx and sinmap.dll. sinmap.avx is the ArcView extension file used by SINMAP.  This file must be placed in the directory called arcview/ext32, which is the standard location for ArcView extension files. sinmap.dll is the binary dynamic link library file containing SINMAP routines.  It must be placed in the arcview/bin32 directory where arcview.exe and all ArcView DLL files are located.

    sinmap.pdf.  (1335KB) Copy of the user's manual in Adobe Acrobat format.  This document also includes 3 case studies in British Columbia. To read this you need the free Adobe Acrobat (TM) Reader.  (314KB) A zip file containing the following four files that comprise a small test example. (16808 KB). Orthoimage geotiff file (with a 1 m pixel size) of the sample area.
    C source code.


    Pack, R. T., D. G. Tarboton and C. N. Goodwin, (2001),"Assessing Terrain Stability in a GIS using SINMAP," in 15th annual GIS conference, GIS 2001, Vancouver, British Columbia, February 19-22. (Adobe PDF 255KB)

    Pack, R. T., D. G. Tarboton and C. N. Goodwin, (1998), "The SINMAP Approach to Terrain Stability Mapping," Paper Submitted to 8th Congress of the International Association of Engineering Geology, Vancouver, British Columbia, Canada 21-25 September 1998.(Adobe PDF 328 KB)

    Pack, R. T., D. G. Tarboton and C. N. Goodwin, (1998), "Terrain Stability Mapping with SINMAP, technical description and users guide for version 1.00," Report Number 4114-0, Terratech Consulting Ltd., Salmon Arm, B.C., Canada. (Adobe PDF 1336 KB).


    The links above point to the most current version is 1.0g (July 4, 2001).

    Changes in Version 1.0g (July 4, 2001)

  1. Increased the number of significant figures in the parameter dbf files
  2. Added Mosaic as well as Merge functions for the combination of grids, named consistently with the underlying ArcView Grid Mosaic and Merge functions.
  3. Added the capability to handle more than 10 calibration regions.  The limit is now 100.
  4. Fixed an issue with the refreshing of calibration parameter values if the table is edited but not saved.  The action is to use values in the edited table even if it has not been saved. 
    Changes in Version 1.0f  (March 14, 2001)
    Fixed a bug that resulted in SAPlot themes not displaying if the calibration region theme contained no data for some landslide locations.  The action is to now exclude these landslides from the analysis.

    Changes in Version 1.0e (November 11, 1999)
    Fixed bug that counted landslides falling in "no data" regions as in the "defended" class.  Now landslides in the "no data" region are excluded from the evaluation of statistics.

    Changes in Version 1.0d  (January 9, 1999)
    1.  Properly initializing global variables no matter how an apr is loaded.  This fixes problems that occurred when SINMAP was a default extension and an existing project that did not use SINMAP was opened using the file/open pulldown menu.
    2.  Eliminates unecessary development code (SINMAP.shadow.c) in the avx.
    3.  Fixes the uninstall routines to get rid of all SINMAP references in projects
    that have had the SINMAP extension uninstalled.
    4.  Disallows using SINMAP if the dll is not available.
    5.  Version 1.0c changes listed below.

    Changes in Version 1.0c (dated November 7, 1998, released November 25, 1998)
    1.  A problem when used in conjunction with 3d analyst due to a name clash has been fixed.
    2.  SINMAP.Statistics script has been fixed to better display calibration statistics when there are multiple calibration regions.  The problem of getting stuck with a particular region has been fixed.  Now if no themes are selected in the view, statistics for all themes are displayed, otherwise only statistics for the selected themes are displayed.
    3.  The contributing area is now displayed using a log scale.  Initial colors have been hard coded to eliminate differences between different arcview versions.  The log scale circumvents the arcview display bug that incorrectly maps colors to grid values when the range of grid values is large (as for contributing area themes).

    Older versions still available by request


    SINMAP was developed with the support of Forest Renewal British Columbia, in collaboration with Canadian Forest Products Ltd., Vancouver, British Columbia. These programs were developed with government funding and are in the public domain, not subject to copyright.  They are distributed freely with the following requests.
    1.  In any publication arising from the use for research purposes, the source of the program should be properly acknowledged and a pre-print of the publication sent to the developers at the address below.
    2.  In any use for commercial purposes or inclusion in any commercial software, appropriate acknowledgement is to be included and a free copy of the commercial software made available to the authors at the address below.


    There is no formal ongoing support for this freely distributed public domain software.  However, we are interested in feedback and can help to the extent that our time permits.  If you find errors, have suggestions, or are interested in any later versions contact the authors.