What is the term for a thematic map in which areas are shaded or patterned in proportion to a statistical variable such as population density?

What is the term for a thematic map in which areas are shaded or patterned in proportion to a statistical variable such as population density?

• A. Choropleth Map
• B. Control Point
• C. Hachures
• D. Map Projection

Answer: (A)

Shading areas on a map to reflect a numeric statistic across regions is a choropleth map. In this type, each geographic unit—such as a state or county—gets a value, and colors or patterns are scaled to that value so you can compare regions at a glance. Darker shades typically indicate higher values (like greater population density), while lighter shades indicate lower values. This approach works well because it leverages fixed boundaries to let you see spatial patterns and contrasts in the data. Other terms don’t describe this kind of map: a control point is a reference location used in surveying or image registration, not a method for displaying data across areas; hachures are relief lines used to hint at terrain, not to convey statistical values; a map projection is about converting the curved globe to a flat map, not about shading by data.

Shading areas on a map to reflect a numeric statistic across regions is a choropleth map. In this type, each geographic unit—such as a state or county—gets a value, and colors or patterns are scaled to that value so you can compare regions at a glance. Darker shades typically indicate higher values (like greater population density), while lighter shades indicate lower values. This approach works well because it leverages fixed boundaries to let you see spatial patterns and contrasts in the data.

Other terms don’t describe this kind of map: a control point is a reference location used in surveying or image registration, not a method for displaying data across areas; hachures are relief lines used to hint at terrain, not to convey statistical values; a map projection is about converting the curved globe to a flat map, not about shading by data.