The Slope tool can be used to create a slope map by identifying the slope from each cell of a raster surface. Contour lines are usually presented as line features in a shapefile or feature class (vector data). However, a slope map cannot be created directly from contour lines because the Slope tool does not support vector data as the input.
The instructions provided describe how to create a slope map from contour lines.
The Topo to Raster and Slope tool require a Spatial Analyst or 3D Analyst license.
Create a digital elevation model (DEM) from the contour layer.
Navigate to System Toolboxes > Spatial Analyst Tools > Interpolation > Topo to Raster.
Select the contour layer as the input feature data.
Specify the location of the output surface raster.
Set the output extent to have the same extent as the contour layer.
Click OK. A raster layer is created from the contour.
For more information on the Topo to Raster tool, refer to the following ArcGIS Web Help topic, Topo to Raster.
Create a slope map from the DEM layer.
Navigate to System Toolboxes > Spatial Analyst Tools > Surface > Slope.
Select the output of the Topo to Raster tool as the input raster.
Specify the location of the output raster.
Select the output measurement.
Click OK. The slope map is created from the DEM layer.
For more information on the Slope tool, refer to the following ArcGIS Web Help topic: Slope.