Hill shading
Topic: Topographical Maps: Relief Representation and Interpretation · NCERT: Class 11, Ch 5 "Topographical Maps"
Meaning
Hill shading shows relief by shading slopes as if a light is shining on them. The light usually comes from the north-west. Slopes facing the light look bright, and slopes facing away look dark. This gives the map a vivid, three-dimensional look, so mountains and valleys stand out. However, it gives no exact heights.
Example
On a shaded relief map of the Himalaya in an atlas, the light is taken to come from the north-west. So the south-east-facing slopes of the ranges in Uttarakhand look dark, and the ridges stand out sharply.
Don't confuse with
- Hachures: these show slope with short drawn lines that are thicker on steep ground. Hill shading uses smooth light and dark tones. Neither gives exact heights.
- Layer tints: these colour whole height zones, such as green for lowlands. Hill shading depends on which way a slope faces, not on how high it is.