Which human-made feature is found at grid reference 31°49'41"S; 26°45'35"E on the topographical map? A - NSC Geography - Question 3 - 2023 - Paper 1

The contour interval on the orthophoto map is 10 metres (Option B).

The photo number for the orthophoto map of NOOITGEDACHT is 31 (Option A).

To calculate the area (A) of the panel, use the formula:

$A = ext{Length} imes ext{Breadth}$

Given that the length is 0.9 m and the breadth is 0.7 m, the calculation is:

$A = 0.9 ext{ m} imes 0.7 ext{ m} = 0.63 ext{ m}²$

To calculate the average gradient, first determine the vertical interval:

$VI = ext{spot height at D4} - ext{spot height at D7} = 150 ext{ m} - 0 ext{ m} = 150 ext{ m}$

Then, use the formula for average gradient:

ext{Average Gradient} = rac{VI}{HE} = rac{150 ext{ m}}{950 ext{ m}} ext{ (express as a ratio)}

The type of slope responsible for the lack of intervisibility between blocks D4 and D2 is a hidden slope or a valley, which obstructs the line of sight.