6 Draw the grid reference index (3124BB) of the topographic map in the space below. Name
the latitude and longitude. Illustrate the alphabetic letters (BB) on the illustration.
1. Name the grid reference index of the map to the east of the above map.
2. Measure the gradient from Δ92 (block C1) to •1526 (block C1). Show ALL the
calculations. Marks will be allocated for calculations. Use the following formula:GRADIENT = VERTICAL INTERVAL(VI)
HORIZONTAL EQUIVALENT(HE)
3. Does the above gradient indicate a gentle, or a moderate or a steep gradient? Explain
your answer.
1. The grid reference index of the map to the east of (3124BB) would be (3125BB).
Latitude: 31° 24' N
Longitude: 118° 24' E
2. To measure the gradient from Δ92 (block C1) to •1526 (block C1), we need to calculate the vertical interval (VI) and the horizontal equivalent (HE).
Δ92 (Block C1):
Elevation: 480m
•1526 (Block C1):
Elevation: 620m
VI = 620m - 480m = 140m
HE = 2 blocks = 2 km
Gradient = VI / HE
Gradient = 140m / 2km
Gradient = 70
3. The gradient of 70 indicates a steep slope. This is because the vertical interval is relatively high compared to the horizontal distance traveled.