What is Flowline Maps? Advantages and Disadvantages of Flowline Map

What is Flowline Map?

A flow map is a type of thematic map that uses linear symbols to represent movement. Flowline mapping is an information visualization technique used to display the paths of objects over time

. It is a tool used by geographers and city planners to study the movement of people and goods.

The map is created by drawing lines between points where an object was observed. As a result, it is a cross between a map and a flow diagram.

The movement being mapped could be anything, including people, highway traffic, trade goods, water, ideas, or even telecommunications data.

The wide variety of moving material, as well as the wide variety of geographic networks through which it moves, has resulted in a wide variety of design strategies.

Some cartographers use this term to refer to any thematic map of a linear network, while others limit it to maps that specifically depict the movement of some kind.

History of Flowline Map

Two maps by engineer Henry Drury Harness, published in 1838 as part of a report on the potential for railroad construction in Ireland, showing the quantity of cargo traffic by road and canal, are the earliest known maps to visually represent the volume of flow.

Others experimented with the technique in Europe over the years until it was mastered by Charles Joseph Minard.

Among his cartes figurative, Minard published forty-two flow maps on a wide range of topics during the 1850s and 1860s.

Among these is his 1869 map of the French invasion of Russia in 1812-1813, which has been dubbed “the best statistical graphic ever drawn. Many of Minard’s maps employ design techniques that, even in the age of computer graphics, have yet to be improved upon.

Waldo Tobler experimented with computerized flow maps in the 1980s.

Early computer-generated maps were not up to Minard standards, but Geographic information system (GIS) and graphics software has improved in the ability to design flow maps.

The use of Flowline Maps

Flowline Maps are used to:

To show the movement of people or vehicles.
To show the movement of goods, either in quantity or value.
To show the flow of energy (e.g., in electricity).
To depict water resources including drainage basins and watersheds, water supply and distribution systems, as well as natural rivers and canals.
To show the flow of information.
To show the relationship between two variables (e.g., population density and number of doctors).
To indicate the ‘flow’ in time of any variable. Demographic changes, for instance, can be depicted using Flow Maps in which the color or symbol shows the density of a certain class at a certain time period.
To represent migration at a very local scale, often used to determine a population’s origin point within a small area like a city or town. Flowline Maps are often used as a tool to show where migrants settled.
To map resource flows in political, social, and economic space. (Cities are often used on a flow map to show their place in the economy.)
To show what various features are doing economically and physically (e.g., peak demand for electricity is shown by how many lights go off or on).
To show changes in the physical environment (e.g., if everything will be eroded or inundated if dams are built).
To show how fast something is moving (e.g., speed of vehicles or the flow of ideas).
To show the network of people and resources that are flowing to and from a central location (e.g., a war zone).

Types of Flowline Maps

the three primary categories for the maps are;

Radial Flow Maps

This is the most basic form of a flow map. It shows the movement from a central point or origin, through a central hub and then to a single destination.

An example of this would be the flow of electricity from a power plant to homes.

The advantages of this type of Flow Map are that it is very clear in showing movement, often looking like a snake or electric circuit.

It can also be a tracer for the flow of electricity.

Corridors are also used to show movement in radial type maps.

Network Flow Maps

This is similar to the radial flow map in that it shows movement from a central point or origin to a single destination.

But it shows movement between multiple hubs instead of just one.

The advantages to this type of Flow Map are that it can show many movement patterns, and because the roads/roads are drawn as ‘networks’ of lines it is often easier to follow the flow.

Corridors are usually used to show movement in Network Flow maps.

Distributive Flow Maps

This shows the movement of a single type of material through routers or hubs.

This can be very useful in showing the movement of material from one location to another.

It is also useful when being used as a means to symbolically represent concepts like pollution, water, or waste.

This type of Flow Map is often used to help with water resource management (e.g., regulation) and the allocation of resources where one type of resource is being taken from one place and distributed to another place.

How to create a Flowline Map

The step-by-step procedure has been discussed below.

Obtain a base map of the desired region.
Determine where you want the beginning to end of your flow lines (beginning and end are not marked on the map, they should be obvious). State how many steps or turns each line will take in your plot. Pick enough points to create a significant amount.
On a computer, trace every edge of the base map except for any roads or waterways (they can be added later).
Draw arrows and lines based on common sense and functional requirements (e.g., commuters, merchants, utilities). Leave the lines open to allow for future expansion.
Add in all the roads and other features that will be connected to your analysis or flow line system. For example, add in railways, bridges, waterways, and whatever else you can think of.
Add symbols to represent each point on every line (e.g., for each point).
In a new file, use different colored symbols for primary roads and secondary roads, etc.
Fill in the blank areas with your completed flow lines.
Create a legend to explain your relationships.
Create a scale diagram to rate each of the steps on your map (e.g., infrastructure, population, etc.).
Label all of your lines and points on the map with a key and/or scale (both are strongly recommended).
Add columns to your chart to make it readable and easier to understand (e.g., in electricity production).

How to interpret Flowline Maps

The steps are:

Identify the geographic phenomenon or feature that is being mapped,
Determine the phenomenon’s characteristics.
Identify the relationships between the property of interest (e.g., correlating with transportation, school enrollment, etc.).
Decide on a scale, units, and units of measurement (e.g., miles per hour, population counts, etc.).
Identify the possible location(s) where this phenomenon can be observed or measured in terms of space and/or time (e.g., monitoring stations).
If possible, collect empirical data and observations (e.g., on the ground) of the phenomenon’s characteristics in order to verify or invalidate your analysis.
Interpret your results/analysis of a flowline map in a way that can be understood by another individual or group of people.
Use your information to make an informed decision (e.g., planning, management, etc.).

Flowline Map Characteristics

The characteristics of flowline maps are:

They show the movement of a unit or commodity from point A to point B,
They show that movement in relation to other things (e.g., roads/roads, drains/drainage systems, etc.).
One of the arc-type charts (circles),
They show the movement of a unit or commodity from point A to point B,
They show that movement in relation to other things (e.g., roads/roads, drains/drainage systems, etc.),
They show a switching pattern (e.g., the flow of electricity).
They show the movement of a unit or commodity from point A to point B,
They show that movement in relation to other things (e.g. roads/roads, drains/drainage systems, etc.),
They show a switching pattern (e.g., the flow of electricity).
They show that movement in relation to other things (e.g., roads/roads, drains/drainage systems, etc.).
They show a switching pattern (e.g., the flow of electricity).

Flowline Maps Advantages

The advantages to flowline maps are:

They often show a big picture.
They are easy to read and interpret for the user (e.g., everyone can understand them).
They are easier to use when compared to other types of maps (e.g., radial, network, etc.).
They are quite useful when trying to draw patterns in large regions; they help to even out the more subtle patterns in a region (e.g., towns, cities, etc.).

Flowline Maps Disadvantages

The disadvantages to flowline maps are:

They are difficult to use as a stand-alone map.
They are difficult for users who do not understand them (e.g., specialists).
They are difficult to use in comparison with other types of maps (e.g., radial, network, etc.).
They are not useful for some purposes; the flow lines can be misleading or the map may be misinterpreted (e.g., not applicable in the long term).
They are difficult to use in comparison with other types of charts (e.g., radial, network, etc.).

Flowline Maps Considerations

The following is a list of considerations for flowline maps:

Decide on your scale(s). Although flow line maps are often used in the United States and some parts of Europe, they are not very common in those countries.
Decide on your units (e.g., km/h or miles per hour).
Decide on your units of measurement (e.g., miles or kilometers).
Check for local factors that may have an impact on the flow line system; these may include but are not limited to, time of day, public holidays, and public events (e.g., parades).
Try to look at the map as a whole whenever possible; focus on the entire map and not just a single item (i.e., draw all of the connections to everything else in the area).
Use a common language whenever possible (e.g., road names instead of numbers).
Be aware that the lines for roads and railways are not the same in most countries (e.g., look at the link between 2 points on a road or railway).
Try to be as specific as possible when naming your lines; use internationally recognized names of places and regions.
Consider using different colors to represent different categories of lines (e.g., red for roads, blue for railways, etc.).
Check whether or not the data is available in a form that can be added to your map (e.g., statistical information, historical information, etc.).
Decide which flows are important for the objectives of your analysis; this will help you to determine where to place them on the map (e.g., on transportation routes). names (e.g., main street, highway, railway line, etc.).

Flowline Map FAQS

What is a flowline map definition?

A flowline map is a type of map that shows the movement of one unit or commodity from point A to point B. The flowline map will appear similar to a traffic jam, with a large number of lines indicating the paths that the units take from one place to another.

Each point on these lines will represent one unit (e.g., gallons), and the flowlines themselves will show how many units were moved in each direction from that location at any particular time (e.g., during each hour or day).

Why use a flowline map?

The flowline maps will help you to show the movements of a unit across an area (e.g., people, electricity, water).

The maps are useful in showing the movement of a unit across an area in relation to other things (e.g., roads, towns, cities).

They can also show trends that may be happening in the area. This can give you an idea of how people move around (e.g., who is moving where and at what time).

What are flowline maps used for?

Flowline maps are used to assess the movement of a unit or commodity from point A to point B, in relation to other things (e.g., roads, drains, streets).

What are flow line maps also known as?

Arc-type charts (e.g., circles), flows, flows lines, flow measure maps, traffic signals, contour maps, line diagrams.

What are the characteristics of flowline maps?

They show the movement of a unit or commodity from point A to point B; They show that movement in relation to other things (e.g., roads/roads, drains/drainage systems, etc.).

What is the advantage of flowline maps?

They show a big picture.

What is the main disadvantage of flowline maps?

They are difficult to use as a stand-alone map.

Why should you use them in your work?

They can be used in many different ways: for example, schools for students, or local governments for planning purposes (e.g., traffic or public transportation).

They help to even out the more subtle patterns in a region; they help to draw patterns in large regions.

What is a traffic flow map?

Flowlines are also known as traffic signals or contour maps. They show the movement of a unit or commodity from point A to point B, in relation to other things (e.g., roads/roads, drains/drainage systems, etc.).

Which map would best represent the traffic flow?

You can use a network map or a traffic flow map. The network map is often the most appropriate option because it shows how things are connected; however, it will not show the direction in which traffic flows.

Traffic flow maps (or contour maps) are more suitable for showing the flow of traffic from one place to another.

What is a traffic flow map used for?

Traffic flow maps are used to assess the movement of a unit or commodity from point A to point B, in relation to other things (e.g., roads/roads, drains/drainage systems, etc.).

What is qualitative distribution map?

Qualitative distribution maps are another form of flowline maps; they show the movement of a unit or commodity from point A to point B, in relation to other things (e.g., roads/roads, drains/drainage systems, etc.). One can also use this type of map in conjunction with quantitative distribution maps.

What is a qualitative distribution map used for?

Qualitative distribution maps are used to assess the movement of a unit or commodity from point A to point B, in relation to other things (e.g., roads/roads, drains/drainage systems, etc.).

What are the characteristics of a qualitative distribution map?

They show the movement of one unit or commodity from point A to B, in relation to other things.

They show that movement in relation to other things (e.g., roads/roads, drains/drainage systems, etc.).

What are the general classes of map projections?

Map projections can be described in terms of their: Class, number of parameters, origin of coordinates or units, etc.

What do you know about map projections?

It is hard to define a general concept of projection because they are so different depending on the purpose. For example, maps can be “flat” (e.g., Mercator projection), “lineal” (e.g., equal area), “cylindrical” (e.g., equidistant projection), “conic” (e.g., conformal mapping).

How did map projections originate?

Map projections were first introduced in the 1600s by a man named Gerardus Mercator (1512-1594). His main motivation in creating these maps was to produce a world map that would be useful for navigation.

What are conformal projections?

Conformal projections are cylindrical or conical map projections that preserve angles and shapes at all locations on the earth. Angles, Areas and directions are correctly represented on conformal maps.

What is a pseudo cylindrical projection?

Pseudo cylindrical projections are those that are mathematically built up from the Mercator.

They are called pseudo cylindrical because their defining meridians (loxodromes) and parallels (rhumb lines) in theory meet and pass through the earth’s axis of rotation. As with any conformal projection, shapes and sizes are generally well preserved on these maps.