Question

Two differences between use of black and blue colours on a topographical sheet

Answer 1

Brown colour indicates various sand features such as sand dunes and sand hills. Agricultural lands are shaded in yellow. Green colour shows forested regions. White patches show uncultivated and waste lands.

Answer 2

USGS standard 7.5-minute topographic maps are printed using these colors: Black for cultural features, boundaries, and names. Blue for water features. Red for highway classifications, built-up areas, fence lines, and U.S. Public Land Survey lines.