(i) On a topographical map two stations A and B are situated at height of 500 metres and 100 metres respectively. If the horizontal distance between them is 2 km, calculate the gradient.
(ii) On a topographical map, two places A and B are given. Calculate the gradient between them.
Solution
(i) Horizontal distance = 2 km = 2000 m
Vertical difference in height = 500 – 100 = 400 metres
Gradient =`"Vertical interval"/"Horizontal equivalent"`
`= 400/2000`
`= 1/5 = 1 : 5`
(ii) Horizontal distance: Measure the distance in cms. between the two places with your ruler. Then from the R.F. given on the toposheet calculate the actual distance between the two places in km and then convert into metres.
Vertical interval in height: Find the difference between the values of the two contours in which the places lie or if no contour lines are shown, find the difference in the spot heights of the two places.
Gradient = `"Vertical Interval"/"Horizontal Equivalent" "Express your answer as a ratio"`
