Which of the following is not a mathematical method of relief representation ?

Question

Accepted Answer

The correct answer is Option 1: Hachure System. Here's why:

*   **Hachure System:** Hachures are short, broken lines drawn on a map to show the direction and steepness of slopes. They are drawn perpendicular to contour lines (if contour lines were present). The closer and thicker the hachures, the steeper the slope. While hachures *represent* relief, they are a *graphical* method, relying on visual representation and artistic interpretation of slope rather than precise mathematical calculation or measurement. The length and thickness of the lines are subjective and not based on specific mathematical formulas.

Now, let's explain why the other options are incorrect:

*   **Bench Mark:** Benchmarks are points of known elevation that have been precisely surveyed and marked. These elevations are determined through mathematical surveying techniques and are used as reference points for determining the elevation of other locations. They are a direct application of mathematical measurement in relief representation.

*   **Form Lines:** Form lines are lines drawn on a map to give a general impression of the terrain. While they are not as accurate as contours, their placement is often based on estimations and interpolations derived from surveyed data or other mathematical methods of elevation determination. They represent an attempt to approximate relief based on some level of mathematical understanding of the terrain.

*   **Contours:** Contours are lines on a map that connect points of equal elevation. The creation of contour lines relies heavily on mathematical surveying techniques, interpolation, and the understanding of elevation data. The spacing and shape of contour lines are directly related to the slope of the land, which can be mathematically calculated. Therefore, contours are a mathematical method of relief representation.

In summary, the hachure system is a graphical representation of relief, relying on visual interpretation rather than precise mathematical calculation, making it the option that is *not* a mathematical method of relief representation. The other options (Bench Marks, Form Lines, and Contours) all involve mathematical principles and measurements in their creation and use.