PS Topographic & Contour Mapping 3

Question 1

A closed contour with hachure marks (tick marks pointing inward) on a topographic map represents:

Accepted Answer

A depression

Answer

Hachure marks on a closed contour indicate a depression, with ticks pointing downhill toward the lower interior of the closed area.

Question 2

When interpolating contour lines from a grid of spot elevations, which method assumes uniform slope between adjacent points?

Accepted Answer

Linear interpolation

Answer

Linear interpolation assumes a uniform (constant) slope between two adjacent elevation points and positions the contour proportionally between them.

Question 3

The horizontal distance between two contour lines on a map is called the:

Accepted Answer

Horizontal equivalent

Answer

The horizontal equivalent is the plan (map) distance between adjacent contour lines, which varies inversely with slope steepness.

Question 4

In LiDAR-based topographic mapping, what does the term 'bare-earth DEM' mean?

Accepted Answer

A DEM representing only the ground surface after removing vegetation and structures

Answer

A bare-earth DEM is produced by filtering out LiDAR returns from vegetation, buildings, and other above-ground objects, leaving only ground-level elevations.

Question 5

On a topographic map, two contour lines of different elevations may touch but never cross because:

Accepted Answer

A single point on Earth cannot simultaneously have two different elevations

Answer

Each contour line represents a unique elevation, so two different contours crossing would imply one ground point has two elevations, which is physically impossible.

(PS) Professional Licensed Surveyor Practice Test

(PS) Professional Licensed Surveyor Practice Test

PS Topographic & Contour Mapping 3