Digital maps (GIS layers) are referred to as map layers in CWMS. When a map layer is included in a watershed, the software displays the map layer as GIS features, points, lines, and polygons.
The common map layer formats recommended for use within CWMS include the Arc Shapefile (.shp) format for displaying points, lines, and polygons and the GeoTiff (.tif) format for displaying gridded data. Other file formats are supported and are listed below.
This file type is the native data structure for the ArcGIS® program. Shapefiles store non-topological geometry and attribute information for the spatial features of a data set in a particular format. For more information on shapefiles, see the ESRI Shapefile Technical Description available here: http://www.esri.com/library/whitepapers/pdfs/shapefile.pdf
A metadata standard which allows georeferencing information to be embedded into a TIF (Tagged Image File Format) file. The added metadata could be map projection datums, coordinate systems, and any other information that will establish spatial references. A TIF file stores raster graphic images and data within a single file.
This is an XML file created in the OpenStreetMap (OSM) file format, which is used for saving street map information. This file is generated by CWMS in the watershed’s map folder and should not be placed or edited by the user.
USGS publishes the file format USGS DEM. A raster file format, .dem files usually contain terrain elevations, but the file format can be used for representing any surface. The format allows for internal documentation of the coordinate system, date of publication, etc. These values are referenced horizontally either to a Universal Transverse Mercator (UTM) projection or to a geographic coordinate system.
This is an ASCII file format used to represent a triangulated irregular network (TIN). TIN data are stored in a simple format that defines the nodes, edges, and triangles contained in the TIN. This format is common for transferring TIN data between software.