GEODESY Lecture 5 Introduction to slope

Slope • Slope is a measure of Steepness. • Slope is sometimes referred to as the “rate of change” between 2 points.

Types of Slope Zero Positive Negative Undefined or No Slope

Slope • If given 2 points on a line, you may find the slope using the formula m= y 2 – y 1 x 2 – x 1

Steep gradient • Contour lines close together

Gentle gradient • Contour lines far apart • A Uniform slope is a slope with evenly spaced contours, it can be for hills of any gradient, weather it is steep or gradual, but they have to be evenly spaced.

Convex slope • Contour lines close together at foot of hill • Contour lines far apart near the crest (top)

Concave slope • Contour lines close together at top of hill • Contour lines far apart near the foot of the hill

Conical hill • Circular shape contour lines • Small crest

Butte • Small flat top • Height is 2 x greater than width

Mesa (table mountain) • Large flat top • 2 x wider than the height • Resistant rock layer at top – dolerite/ granite

Dip slope and Scarp slope • Dip slope = gentle slope of mountain • Scarp slope = steep slope of mountain

Homoclinal ridge • A mountain with a clear dip and scarp slope

Valley and Spur • Valley = contour lines bend (V) towards the top of mountain • Usually a non-perennial stream flowing down • Spur = contour lines bend towards the foot of mountain • Flank on both sides of a valley

Poort, Cliff and Saddle