What is a flow-line map used to depict?

A flow-line map is specifically designed to depict the movement of people, goods, ideas, and other phenomena across various locations. This type of map utilizes arrows or lines to illustrate the direction and volume of movement, making it particularly useful in visualizing migration patterns, trade routes, or the spread of cultural practices. By representing these flows, the map provides insight into the dynamics of interaction and exchange between different regions, showcasing not just where things are happening, but how they connect and influence one another.

The other options focus on more static representations. Elevation changes would be depicted using contour lines or shaded relief, emphasizing physical terrain rather than movement. Political boundaries are represented through distinct lines marking the borders of countries or regions. Physical geography involves characteristics of the Earth’s surface, such as landforms and climates, often illustrated through different types of maps that highlight those features without emphasizing movement. Thus, flow-line maps stand out as a unique tool specifically for analyzing movement and interaction rather than static features.