Chapter 7, Problem 1LR

Determine the contour interval used on this map

Contour interval:_________________ feet.

Summary Introduction

The counter interval used on the given topographic map of a hypothetical area.

Introduction:

Topographic maps represent large scale structures of the Earth surface such as hills, streams, and valley. The contour interval is defined as the difference in the vertical elevation between the adjacent contour lines.

Explanation of Solution

Contour interval is calculated by the given formula:

$\text{Contour}\text{interval}=\frac{\text{Difference}\text{in}\text{elevation}}{\text{Number}\text{of}\text{contour}\text{lines}}$ …… (I)

The difference in elevation from the given map is calculated as:

$\begin{array}{rll}\text{Difference}\text{in}\text{elevation}& =& 200\text{feet}-100\text{feet}\\ & =& \text{100}\text{feet}\end{array}$

Number of contour lines are 5

Therefore, by substituting the following values in equation (I),

$\begin{array}{rll}\text{Contour}\text{interval}& =& \frac{100\text{feet}}{5}\\ & =& 20\text{feet}\end{array}$

Hence, the counter interval used on the given map is 20 feet.