For a reservoir watershed management project in Taiwan a spatial database has been
established. The database contains information about landslides, soil samples, and
also stores geo-referenced air photographs and other geographic information. The UMN
Mapserver solution enables viewing, zooming and querying of spatial information in
different GIS formats in a web browser. The web based application was developed to
enable easy access to the different  spatial information layers needed for integrated
watershed management.

The Watershed GIS Mapserver solution is based on a combination of Apache Web Server
and the UMN Mapserver. The flexible Mapserver solution was used in this case to
display and enable querying of spatial information that was collected for an almost
700km2 large watershed in Taiwan. Supported vector formats are: ESRI shapefiles,
PostGIS, ESRI ArcSDE and many others via OGR. Raster formats supported: TIFF/GeoTIFF,
EPPL7 and many others via GDAL. Vector data is used for sub watershed boundaries,
streams, roads, sample points and landslides. While raster data is used to display
digital elevation model data in GRASS raster format, land use maps and air
photographs in GeoTIFF format.
When querying sample points, attribute information is shown in a template providing
details about caesium-137 (137Cs) activity in soil samples, date of sampling,
coordinates and elevation and when present also the number of erosion pins. In the
near future the calculated and actual erosion rate for each sample location will be
added. Photographs taken during the sampling can be viewed as well as a graph showing
the depth distribution of 137Cs activity in profile samples. For landslides the
landslide area is shown in the template. In the future the web-based spatial
watershed database will show variation in erosion rates across the watershed. A
training will be given to watershed managers to instruct office personnel how to use
the system. The author believes the use of FOSS GIS software enables flexible and
cost-effective implementation of this and other GIS applications in government and
non-profit organizations.