GEOLOGY

Detailed explanation-1: -If the numbers associated with specific contour lines are increasing, the elevation of the terrain is also increasing. If the numbers associated with the contour lines are decreasing, there is a decrease in elevation. As a contour approaches a stream, canyon, or drainage area, the contour lines turn upstream.

Detailed explanation-2: -Contour interval: The change in elevation from one contour line to the next is always the same within the same map. Many maps have either a 40-or 80-foot contour interval: An 80-foot interval simply means that each contour line is 80 vertical feet away from the next closest line.

Detailed explanation-3: -Put simply, contour lines mark points of equal elevation on a map. If you trace the length of a line with your finger, each point you touch is the same height above sea level. If you were to walk the path of a contour line in real life, you would remain at the same elevation the whole hike, never traveling up or down.

Detailed explanation-4: -On topographic maps, each contour line connects points at the same elevation. The contour interval is the difference in elevation between adjacent contour lines.

Detailed explanation-5: -In hilly areas, the contour lines are close together while they are wider apart on flat slopes. The closer the contour lines, the steeper the slope. The wider the contour lines, the flatter the slopes. On a hill, the contour lines form circles; whereby the values of their elevation increase from the edge to the centre.