Deriving contour lines from a surface

Contour lines are a familiar way of representing surfaces on maps. A contour is a line through all contiguous points with equal height (or other) values.

You can create contour lines for a raster, triangulated irregular network (TIN), or terrain dataset surface. You can use the following geoprocessing tools to create contours from a surface.

Creating contour lines from a raster surface

• To create contours or isolines from a raster surface, use the Contour geoprocessing tool.
• To create contours or isolines based on a list of contour values, use the Contour List geoprocessing tool.
• To create contours from a raster surface and independently generate contours on either side of a barrier, use the Contour With Barriers geoprocessing tool.

Creating contour lines from a TIN or terrain dataset surface

• To create contours or isolines from a TIN or terrain dataset surface, use the Surface Contour geoprocessing tool.

Note:

• The geoprocessing tools used to create contours from surfaces require ArcGIS Spatial Analyst and/or 3D Analyst extensions.
• In certain instances, the last valid contour line might not be produced when creating contours using TIN surfaces. This is an algorithmic limitation common to computer contouring software. To ensure that all valid contours are generated, add a very small negative value to the base contour field to slightly shift the data.