Calculating the Gradient Mr Daly 16/02/2019 11:18 PM16/02/2019 11:18 PM Calculating the Gradient The grade of a slope is important to understand in walking, road building, roofers, landscapers, train track laying, etc. Calculating gradient in geography Gradient in geography is different to gradient in maths. It is always expressed as 1:x, ie 1:4, or 1:1. the second number in the expression is run/rise, so the way to calculate is: run/rise  (where the run and the rise are measured in the same units). Tricks and traps Not expressing the gradient in the form 1:x using rise over run as in maths With a contour map, the contours are likely to be expressed in metres (for the rise) whereas the run is likely to be measured in km. So, make sure the rise is also in km (ie 700m = 0.7km) before applying the formula. 1: run/rise

Calculating the Gradient Mr Daly 16/02/2019 11:18 PM16/02/2019 11:18 PM Calculating the Gradient Gradient measures the steepness of a slope Step 1: Measure the rise (difference in height between 2 points) Step 2: Measure the run (the distance between 2 points). Step 3: Make sure that you convert the scale into metres Both the rise and run need to be expressed in metres.

Calculating the Gradient Mr Daly 16/02/2019 11:18 PM16/02/2019 11:18 PM Calculating the Gradient Say the rise is 42 metres and the run is 600 metres. 42m 600m divided by 42m equals 14.28 600m The answer is then written 1 : 14:28 The answer is written like this to show that for every 1 metre up, you travel 14.28 metres across

Calculating the Gradient Mr Daly 16/02/2019 11:18 PM16/02/2019 11:18 PM Calculating the Gradient The gradient is the rate of change of a slope. Another way to think of it is that gradients measure steepness. This can also be shown as a percentage. This then shows, how fast the slope is increasing or decreasing http://www.youtube.com/watch?v=3QFJ_uv2mGw

Calculating the Gradient Mr Daly 16/02/2019 11:18 PM16/02/2019 11:18 PM Calculating the Gradient Say the rise is 100 metres and the run is 200 metres. 100m 200m divided by 100m equals 2.00 200m The answer is then written 1 : 2 The answer is written like this to show that for every 1 metre up, you travel 2 metres across 1 : 2 = 20% The answer can also be written like this to show you the grade of the slop

Vertical Distance (Rise) Horizontal Distance (Run) Slope Vertical Distance (Rise) Horizontal Distance (Run) Gradient Incline Grade A 23m 115m 1:5 20% B 16m 1:51 C 28m 448m D 564m 1:12 E 10m 1:30 F 480m 1:20

Mr Daly 16/02/2019 11:18 PM16/02/2019 11:18 PM Types of Slopes There are two main types of Geographical slopes. They are Convex or Concave

If a slope is not Convex (A) and Concave (B), it is then Linear (C) Mr Daly 16/02/2019 11:18 PM16/02/2019 11:18 PM Types of Slopes If a slope is not Convex (A) and Concave (B), it is then Linear (C)

Mr Daly 16/02/2019 11:18 PM16/02/2019 11:18 PM Types of Slopes