Survey Symbols Practice Test

Contour lines connect points that share the same elevation, so they reveal the shape of the land—the highs, lows, ridges, and valleys. The contour interval is the vertical difference in elevation between adjacent contour lines, and it is fixed for the map. For example, with a 20-meter interval, each neighboring line represents a 20-meter change in elevation. How closely the lines sit tells you about slope: tightly spaced lines indicate steep terrain, while widely spaced lines show gentler slopes. Contour lines don’t depict drainage alone, nor do they map roads; those features would be shown by other map elements. The interval is about vertical height, not horizontal spacing, and it helps you interpret elevation changes across the map.