When you have geospatial data, you will often look to make a map when you have finalized your analyses. Just like in other figures and documents, some elements are required to create a map that will easily and accurately describe your data to viewers. For example, graphs must have labeled axes and documents require references to be able to interpret them appropriately. Maps can be made without these essential elements but it will reduce the potential impact of your work. Remember, your map is one possible representation of reality, and the user or viewer needs context to place the map in the 'real world'.
Figure: This 'map' does not give the viewer enough information to determine the context of the data.
All maps should have the following essential elements:
An important starting point for your map is to consider why you are making the map, and what or who is it for? This will help you decide what are the important elements to highlight in your map and what information is less important for the viewer.
Using our example map here, we want to highlight the impact of construction on parking (why) at Trent University in summer 2025. Since this is all occurring in the north-east corner of Trent lands, it may be beneficial to centre the map on this area for an emailed update (what) to parking pass holders (who). However if this map were going to be displayed on signs throughout campus (what) to inform the general public (who), it would make sense to have the entire campus contained within the map.
Something to consider is whether you will generate a map document or map figure. A map document is a stand-alone map like you would find at a trailhead or the entrance to a park. It is designed to be interpreted on its own with no other resources given to the viewer. A map figure is instead supported by additional text or documents, like what you would find in a research article for a graph or table. A key distinction here is that map figures will have a figure caption (which can provide additional context and explanation via text) whereas map documents do not.
Interactive maps also require the same map elements, but as they are 'living' documents these features can be resized, moved, and disappear depending on the context of the map. They may also require additional metadata and functionality to ensure it can be understood by a wide and diverse audience.
The map you design should be an appropriate physical size and shape for your desired context and have an appropriate level of your spatial data showing. Map documents may require certain dimensions and size to fit in their desired frame (e.g. 36" x 24" landscape orientation) whereas map figures may require a certain file type and resolution in order to be added to and resized within a document (e.g. a file in .png format at 300dpi). It is important to know what the requirements are for your map to be published in its best form!
The zoom level of the map is also important to set appropriately to convey the message on your map. This is linked to the scale of the map (see 'Scale bar or Scale Number') but here we are considering how we see the map visually - are all the data present and legible? In some situations it can be difficult to balance showing enough detail to distinguish objects on the map with fitting all of your data on the map. Some maps are best presented as a series of maps or as two similar maps displayed together. Another popular option is to include an inset map to show the greater context of the study site location (e.g., an inset map of Canada to show where Peterborough is in relation to the country). Remember to think about why you are making your map to help guide you.
Some maps have marks or ticks on their borders labelled with the latitude and longitude of the map. This can be an efficient way to show where your map is in space without the need for a separate, broader map showing the data in context.
Other than including all of the data in a distinct and legible manner, there is no correct answer here. Do what feels and looks best to you!
Figure: a 'map' with a poor zoom level. While it focusses on the closed parking lots, the viewer (who) cannot see any greater context of where they may encounter this.
The north arrow or compass rose are a common feature of maps, and you often see them pointing straight up. They are presented on the map to help orient the user in space by direction: think 'where does this map occur in real space?'
North arrows do not have to point up! If your data and map dimensions are better suited to be off centre, you can rotate your map for better balance in your document (what). In some scenarios, it may be easier for the viewer (who) to read your map if it is oriented so that 'up' is further away which may not necessarily be north.
A compass rose is simply a figure that includes more than one direction (instead of just north). Often these will show the four cardinal directions (north, south, east, west) but some may show intermediates (e.g. NE, WSW) or they may only show two directions (e.g. North and South). Historic maps often used these as a point of embellishment with significant artistry applied to them.
You may occasionally see or require a map with what appears to be two north arrows separated by a defined angle. These are displaying the difference between true north (toward the north pole) and magnetic north (where the earth's magnetic field points vertically downward). This can be important for navigation especially in northern latitudes where the difference between these two values are exaggerated as you get closer to the north/magnetic pole.
Most modern GIS software will include a variety of north arrows and compass roses; choose whichever looks best to you! Just make sure the directions are pointing in their true orientation.
Figure: Three different north arrows
You may find maps from earlier in history with an emphasis on other cardinal directions, as north being at the top does imply that the northern hemisphere (and therefore Europe & North America) are more important as this is how English is read (top to bottom). Some maps prioritized other cardinal directions to enhance their importance (e.g. south at the top for southern countries, or east being at the top for countries on the east coast) or referenced a specific location towards the top (e.g. the direction of a major religious site being at the top, regardless of if it is on the map). Sometimes, these map elements can tell you an additional story about the map in question.
The scale bar or scale number is an important piece for the user to understand how large the map is compared to reality, or how far some point on the map is compared to another point.
A scale bar often takes the form of a line or rectangle that is broken up into segments which are labelled by distance (e.g. the distance between two marks or of one block is equal to 1 kilometre). Scale bars contain at least one segment, but may contain several at different distances (e.g., one segment could be 1km, and another 5km). It is very important that the scale value is included here as this can take many forms that would offer very different perspectives of scale (like kilometres compared to centimetres).
A scale number is slightly simpler and presents the scale in a ratio or comparison of two numbers: the first reflects the distance on the map, and the second reflects the distance in real space, separated most often by a colon (:) or 'to'. In modern map making with computers, this scale is often calculated with the same units and is shown as a unitless measure (e.g., 1:50,000). Some maps (especially older ones) may use two different units to represent their scale (e.g. 1 inch to 1 mile) as these would have been measured on paper with a ruler. You may also find some odd units compared to what are used today - chains and knots were not uncommon measures!
Remember that a map is a representation of reality, and depending on the who, what, and why being addressed the scale bar or number can be rounded up or down to display a 'round' number (like 100km instead of 99km). With modern GIS the scale bar or number may automatically 'snap' to a round number to assist in making a clean map. While this is not required, it is recommended to have a round number and easy to read scale.
Some maps have marks or ticks on their borders labelled with the latitude and longitude of the map. This can be an efficient way to show where your map is in space without the need for a separate, broader map showing the data in context.
Like other aspects of map making, the choice of scale bar, scale number, and the style of either is up to you. Remember to balance your map elements and consider how the map may be used (who) - how will readers be able to compare a segment to a common distance on the map, and are the units in a suitable distance for the length of journey and method of transport?
Figure: Different examples of scale bars and texts
A point of confusion can arise when talking about the scale of a map, such as large scale and small scale. It may seem that a large scale map would show a large area (like a country) with less detail, but in fact it shows a small area (like a city) with more detail. Why is this the case? If you think back to the scale number, the largest possible value of a ratio starting with 1 is 1:1 (or 1/1 = 1). This would represent a map where each unit of distance is the same on the map as the real world, which would be very zoomed in! As the map 'zooms out', the ratio changes (e.g. 1:100, 1:10,000) and the number represented by the ratio becomes smaller (e.g. from before: 0.01, 0.0001).
TL;DR: a large scale map represents a small area, and a small scale map represents a large area.
The legend can be an integral part of your map, especially when a wide variety of data are being displayed. The legend should show what each feature on the map represents by displaying an example of the feature next to a label.
You will often see these with coloured boxes, lines, and points to represent vector data (polygon, line, and point data). There may also be different sizes of points or lines to represent different feature types (e.g., thicker/wider lines for highways compared to city roads).
Raster data may have different descriptors but often represent multiple data values in one legend entry, using a ramped scale of colour or discrete colours and a range of values. Generally speaking, imagery and simple basemaps (like the defaults shown on ArcGIS or Google Maps) are not given a legend entry but rather appear in the reference list as a source of data.
If the legend is getting too long or large, it may be best to consider a map series (with multiple individual maps) or to zoom out and have the legend appear in 'blank space'. If the legend is difficult to read when it overlaps with data on the map, consider adding a semi-transparent background to enhance readability while maintaining a view of the underlying data. A good starting point is a 30-60% transparency white or black background, with black or white text respectively.
Figure: A legend for a parking map of Trent University.
A legend should be intuitively obvious to the user. If the legend needs more explaining, more information needs to be on the legend! Legends do not need to be named or titled. Similar to map titles or captions, as well as the scale bar and north arrow, the legend does not need to be identified as such: just include the data examples and labels.
Depending on what you are making your map for, you will need a map title or figure caption. If it is a stand alone map document, include a title on the map. If it is included within a document, there should be a figure caption. While the map is displaying a location, the title or caption should place it in the greater context by answering where and what the map displays. There should be some form of geography in the title, like 'Parking Lots at Trent University' or 'Provinces of Canada'. Note that these also include the main data being displayed (parking lots, provinces); other data may be included, but this is the message (why) the map is delivering.
Map titles should reflect what the map contains and adequately describe it for the audience (who). They should be concise and convey a summary of the map in a few words. This does not have to be a full sentence and can often take the form of 'Data - Site' such as 'Industrial sites in Peterborough, Ontario'. This text should be the most obvious on the map but not necessarily at the top or centre. If the map is complex or contains an abundance of data, it may be prudent to have a subtitle that gives further explanation for the user.
Figure captions should similarly describe the map, but can be a few sentences long. Standard rules for figures apply here (as the map is 'just' a figure) so refer to the guide or specifications for your document to ensure it meets the criteria outlined. As with map titles, the figure caption should include some form of data and geographic descriptor (often contained in a short preliminary sentence), such as 'Study sites and water quality measurements in the Otonabee River'. Sometimes, this may be all that is required for a figure caption. Like other figures and captions, the map and its caption should be able to be interpreted without the rest of the document, so be sure that any acronyms or definitions are included in the caption.
Figure: A map document with a title. Please note that this represents a map document and normally map figures with a caption like this should not have a title.
A map title should not contain 'Map of...'. as it should be obvious that a map is what is being displayed. Similarly, book titles do not always contain 'Book of...' and websites are not titled 'Website of...' While we want to make things obvious for the reader, we may assume a basic knowledge of the world and what a map is.
Like other published media, listing an author and/or publisher is important for map making. This allows the user to identify who made the map and who to contact if further questions arise.
Authors are fairly easy to interpret: these are the individuals that created the map.. Like authorship in research, this may refer to the individual who created the map and/or individuals who contributed to the map project (if part of a team). Publishers may be listed if the work legally belongs to an entity rather than an individual (e.g., 'Published by Fisheries & Oceans Canada'). A copyright statement may also be included for the author and/or data referenced on the map if appropriate.
A simple authorship statement can be 'Created by: Guy Map', and is often adjacent to the date the map was made.
Figure: A map of parking on Trent University Symons campus, July 2025, featuring a labeled author, date, projection, and data sources. Please note that this represents a map document and normally map figures with a caption like this should not have a title.
Authors and publishers can also provide additional context for the viewer. Every creator will have their own bias as to what to include (or not) on a map, and some publishers may have more reliable or accurate data than others. During the early days of surveying in North America, it was not uncommon for some unscrupulous individuals to steal data from other publishers for their own work! This is where the concept of phantom settlements or 'paper towns' come from, wherein an author would create fake data on a map in order to catch other plagiarizers in a copyright trap.
The date of creation of a map can be more important than you may think. This is the date the map document or figure was created, not necessarily the date the data were collected or created or the date of the map title (those would be included in the reference list).
This one is pretty simple: just write the date! An example statement could be 'Created on: 9 September 2025', and will often be near the authorship statement.
Figure: A map of parking on Trent University Symons campus, July 2025, featuring a labeled author, date, projection, and data sources. Please note that this represents a map document and normally map figures with a caption like this should not have a title.
To display the importance of a date of creation, I can create a map today of the Great Lakes and surrounding towns in 1800, but this may be different from a map the same thing created in 1800 due to changes in data resolution or how representation has evolved over time. We have much more accurate and precise data on the shorelines and locations of cities now than was available in 1800, and placenames may have changed over time or may be different depending on the intended audience.
The projection of the map can inform a viewer how the data and space are altered to show what is a three dimensional object on a flat surface. Projections can preserve area, distance, or angles but cannot maintain all three perfectly. Some projections focus on smaller areas to increase accuracy whereas others are geared toward more continental or global display and mapping. This means that certain projections are better suited to a particular audience, viewer, or map type.
You may find that projections are listed as a code following EPSG:, which is a database containing a list of most projections using a numeric code. Common ones you may encounter are EPSG: for WGS 84 and EPSG:26917 for NAD83/ UTM zone 17N.
Like an authorship statement and date of creation, simple projection statement could be 'Projection: NAD83 UTM Zone 17N' or 'EPSG:26917'.
Figure: A map of parking on Trent University Symons campus, July 2025, featuring a labeled author, date, projection, and data sources. Please note that this represents a map document and normally map figures with a caption like this should not have a title.
As maps are representations of reality, there are inherent emphases and biases placed in them. While the common Mercator projection was chosen since it maintains straight rhumb lines (lines of latitude and longitude) which can make navigation easier, it severely distorts area near the poles and causes land masses in the northern hemisphere in particular to appear larger than they are in reality. While Greenland may seem as large as Africa on these maps, this northern landmass is actually under 10% of the size of the equatorial continent.
Did you know? EPSG originally stood for European Petroleum Survey Group, which has since ceased as an entity but the acronym remains as it became synonymous with projections.
Just like a research paper, a good map should have a reference list denoting where the data came from. How you appropriately cite the data will depend on the guidelines for your map or document, but at a minimum it should include the data/layer name, author, and date created and/or accessed (a link is also common). You can find more information under Citing Geospatial Data in our GIS LibGuide.
If you don't know where the data came from, check the metadata or ask whoever acquired the data if they know more. It's a good idea to download all related metadata for your own records and keep track of the sources you have been using for your map project.
As these data are important but not an integral part of the map, they are often 'hidden' in a corner of the map. You may notice that if you have a basemap enabled in ArcGIS Online or Pro, the software will automatically include a reference to this data that you cannot remove (usually at the bottom right corner of the map). Taking cues from this, you can use small text on a semi-transparent black or grey background to reduce the visual prominence of your references. A copyright statement may also be included for the data referenced and/or author on the map if appropriate.
A reference list would appear similar to those you find in a research paper, listing data like 'Contour Lines: Ontario Ministry of Natural Resources and Forestry, Updated 23 May 2024, geohub.lio.gov.on.ca'
Figure: A map of parking on Trent University Symons campus, July 2025, featuring a labeled author, date, projection, and data sources. Please note that this represents a map document and normally map figures with a caption like this should not have a title.
There are quite a few elements to include on your map! It may be difficult to manage all of these together or imagine how your map can be 'correct'. It can help to try and balance elements throughout the map. For example, you may put your north arrow, scale bar, and attributions all on one side of the map to 'balance' a particularly long legend. If you have the freedom to choose your map size, consider changing from landscape to portrait to fit the data better within the map. Sometimes you may have to 'zoom out' to get enough free space for your map elements, or you could consider creating a map series if the data are hard to overlay and view all at once.
Another important consideration is the use and balance of colour on the map. You may wish to employ a colour scheme to match the organization being represented on the map, or create something in black and white to better fit within a text document. It can be difficult to manage a map with a plethora of data classes as the colours may be difficult to distinguish between. A common colour ramp to show good from bad is green to red, but please note that this is difficult for people with red/green colour blindness to comprehend which is relatively common. A good website to assist in deciding on colour values is Color Brewer 2.0 which allows you to specify many requirements like number of data classes, colourblind safe, and print friendly: ColorBrewer: Color Advice for Maps
This is the time to let your visual artistry shine through and be confident in your layout and design!
The final decisions for map making are how to output your map. Again, the who, what, and why here should tell you what kind of file type or media, size, and dimensions you need for your output. We already went over this in the Map Size/Zoom section but it's important to ensure the map comes out looking the way it was intended. The dimensions will be set by the guidelines you are provided, and as a general rule a 300dpi image output is of good quality for most applications.
Now the map is ready to be shared to an audience, and you can be certain it will be a coherent and stunning work of art and science!
MaDGIC is hosting a map competition for GIS Day! Details on the timing and where to apply will be posted on their section of the Library website and at the Trent University GeoHub: Trent GeoHub. If you have a map that you have already created as part of another project, you are welcome to submit it. Maps will be displayed publicly in Bata Library and on our website so please consider this for your submission.
All of the map elements listed in this guide are suggested for your submission, but not mandatory. However, now would be a good time to start adding these elements to all of your future maps!
Static posters will be printed on 18" x 24" paper and can be displayed in portrait or landscape orientation. We suggest that your submission be scaled to this ratio (3:4) but other dimensions such as letter will fit with a blank border around them. Files should be .jpg, .png, or .tif and at 300dpi for the best clarity when printing at a larger scale. If your map is lower resolution, please let us know.
Digital maps (web or StoryMaps) should be have their sharing level set to be publicly visible. An interactive display will be present in the library along with a link for other community members to see and use your map. Interactive elements are encouraged.