# Quick Answer: What Is The Rule About Contour Lines That Cross Rivers?

## What is the importance of contour lines?

The purpose of contour lines is to represent the tridimensional shape of the terrestrial surface on a bidimensional map.

Contour lines are the intersection of an horizontal plane parallel to the reference level and the topographical surface to describe.

Consequently: Contour lines are always closed curves..

## What is the elevation difference between contour lines?

The elevation difference between two adjacent contour lines is called the contour interval (CI). Usually the contour interval is noted on the map legend. In most topographic maps every 5th contour line is drawn in bold print or wider than other contours. Such lines are called index contour lines.

## What is every fifth contour line called?

A contour map is another name for a topographic map, illustrated from contour lines. … To make topographic maps easier to read, every fifth contour line is an index contour. The index contour lines are the only ones labeled. The index contours are a darker or wider line in comparison to the regular contour lines.

## What do contour lines do when they cross a river?

When contour lines cross a stream, they form a “V” that always points uphill. As a general rule, water flows downhill perpendicular to contour lines.

## What are the 5 Rules of contour lines?

Rule 1 – every point of a contour line has the same elevation. Rule 2 – contour lines separate uphill from downhill. Rule 3 – contour lines do not touch or cross each other except at a cliff. Rule 4 – every 5th contour line is darker in color.

## What 2 types of lines show elevation differences?

Contour lines are used to show elevation on a topographic map. Lines or isolines on a map that connect points with the same elevation. What does each contour line on a map show? Each contour line shows a different elevation.

## How do contour lines work?

Contour lines are lines drawn on a map connecting points of equal elevation, meaning if you physically followed a contour line, elevation would remain constant. Contour lines show elevation and the shape of the terrain. … In order to keep things simple, topographic maps show lines for certain elevations only.

## What is meant by contour interval?

A contour interval is the vertical distance or difference in elevation between contour lines. Index contours are bold or thicker lines that appear at every fifth contour line. If the numbers associated with specific contour lines are increasing, the elevation of the terrain is also increasing.

## Can contour lines cross?

Contour lines can never cross one another. Each line represents a separate elevation, and you can’t have two different elevations at the same point.

## What are 3 types of contour lines?

There are 3 kinds of contour lines you’ll see on a map: intermediate, index, and supplementary.Index lines are the thickest contour lines and are usually labeled with a number at one point along the line. … Intermediate lines are the thinner, more common, lines between the index lines.More items…

## What are the basic features of contour lines?

Other characteristics of contour lines are: – Horizontal distance between contour lines is inversely proportional to slope. – Uniform slopes have uniformly spaced lines. – Along plane surfaces, contour lines are straight and parallel. – Contour lines are perpendicular to lines of steepest slopes.

## What does it mean when contour lines are far apart?

Contour lines that are relatively close together indicate a slope that is fairly steep. Contour lines that are further apart indicates a slope that is relatively flat.

## What is the space between contour lines called?

Contour lines–usually curved, parallel brown lines–show the shape and elevation of the land by connecting points of equal elevation. … The space between the contour lines is called the contour interval and represents a specific (set) distance.

## What do you mean by contour lines?

Contour line, a line on a map representing an imaginary line on the land surface, all points of which are at the same elevation above a datum plane, usually mean sea level. map: contour lines. The diagram illustrates how contour lines show relief by joining points of equal elevation.