This layer provides slope values calculated dynamically from the elevation data (within the current extents) using the server-side slope function applied to a Terrain layer. The values are integer and represent the angle of the downward sloping terrain (0 to 90 degrees). Note slope is a function of the pixel size of the request, so at smaller scales the slope values are smaller as pixel sizes increase.
WARNING: Slope is computed in the projection specified by the client software. The server resamples the elevation data to the requested projection and pixel size and then computes slope. Slope should be requested in a projection that maintains correct scale in x and y directions for the area of interest. Using geographic coordinates will give incorrect results. For the WGS84 Mercator and WGS Web Mercator (auxiliary sphere) projections used by many web applications, a correction factor has been included to correct for latitude-dependent scale changes.
What can you do with this layer?
Use for Visualization: No. This image service provides numeric values indicating terrain characteristics. Due to the limited range of values, this service is not generally appropriate for visual interpretation, unless the client application applies an additional color map. For use in visualization, use the Terrain: Slope Map.
Use for Analysis: Yes. This layer provides numeric values indicating the average slope angle within a raster cell, calculated based on the defined cell size. Cell size has an effect on the slope values.
For more details such as Data
Sources, Mosaic method used in this layer, please see the Terrain layer. This layer allows query, identify, and
export image requests. The layer is restricted to a 5,000 x 5,000 pixel limit
in a single export image request.
This layer is part of a larger collection of elevation layers that you can use to perform a variety
of mapping analysis tasks.