1. THE SHAPE OF THE GROUND RELIEF is a term used to describe the shape of the ground. Relief has two elements:1. HEIGHT 2. SHAPE HEIGHTS can be represented in 3 ways: 1. BENCHMARKS (leveled heights) 2. TRIGONOMETRICAL (trig) POINTS 3. SPOT HEIGHTS SHAPE is indicated through the use of contour lines. 405.06 Red Star OHP-1

2. CONTOUR LINES A contour line is like a path. If you walk around a hill at the same level, you are following a contour. By walking around the hill at a higher level, another contour is formed. A hill can also be cut into equally thick horizontal slices. The outline of each slice is a contour line. 405.06 Red Star OHP-2

3. SHAPE OF THE GROUND Every feature on the ground can be seen in 3 ways: 1. Perspective: appears as if seen from above 2. Elevation: Side-on view 3. Plan: shows the contour lines as they appear on a map. 405.06 Red Star OHP-3

4. SLOPES 1. Where the slope of a hill is gentle, the contour lines are spaced far apart. 2. Where the slope of a hill is steep, the contour lines are close together. 3. Evenly spaced contour lines mean a uniform slope. 405.06 Red Star OHP-4

5. CONTOUR PATTERNS (1) CONVEX SLOPES: The hill is steep at the bottom and flattens out near the top. CONCAVE SLOPES: The slope is gentle at the bottom of the hill and gets steep as you near the top. 405.06 Red Star OHP-5

6. CONTOUR PATTERNS (2) Ridge with a Saddle Valleys Spurs with Re-entrant Separate Hills 405.06 Red Star OHP-6