Effective Cartography

Nuts and Bolts of Cartography with ArcGIS

This tutorial provides hands-on experience with the techniques of producing a reference map to that will be a framework for discussing a place and its context. The next several tutorials will use this base map to develop several types of thematic maps. A topographic reference map provides an understanding of a situation as a network of named physical and cultural features connected by corridors of various types and interrupted by edges, barriers and invisible boundaries. The reference map supports discussions of the critical aspects of a place in a geographic and decision-making context. This discussion-support is accomplished by labeling the critical places, transportation routes that lead to and through the place and other features within the area of interest and the area that surrounds it.

Introducing a decision-making conetxt into this exercise forces us to be concise: to use the map to focus the attention of our audience on specific elements of the situation that are part of a focused discussion. Not only will this direct and limit the amount of work that we are doing, but will also provide an easy means of evaluating the map with respect to its specific purpose.

Download the Tutorial Dataset

References

We assume an understanding of the concepts and techniques covered in these tutorials:

Tutorial Outline

The Layout

Arranging the Background of your Map's Graphical Hierarchy

Adding Title, Captions and Other Marginalia

Adding Labels and Diagramatic Shapes to the Map

Finishing Up

Establish Goals for a Simple Context Map and Introductory Aaption.

Every project that involves spatial decision-making should include a map and a descri[ption of the context. Building this map helps the analyst to understand the essential elements of the place that are known to locals. The map and description also demonstrate to the clients and the public that the analyst understands the context of the study. The goals for context maps of all types are discussed in more detail on the page Elements of Cartographic Style

Example Setting: Union Square and the Green Line Extension

We want to understand how the proposed extension of the MBTA Green Line will affect the city of Somerville, Massachusetts. This particular mapping project will examine the context of the neighborhood Union Square as it is today, as the setting for two of the proposed stations on the greenline extension. An important aspect of this context is the existing transit stops around the square.

Choose an Appropriate Projection for the Map

Maps covering cities, states and provinces (scales greater than than 1:250,000) should have consistent planimetric scale. To put it another way, people wil expect to be able to use a scale to infer tru distances and shapes on the map. Angles reflecting North, Eaast, South and West should be ninety-degrees apart. In order to assure that these assumptions are true the map-maker needs to choose an appropriate projection for the map. These principles are covered in detail on the page, Fundamentals of Geographic Refe4encing Systems and Map Projections The projection that ArcMap chooses for your map is determined by the inherent projection of the first data set that you add to the map. This default projection is often inapropriate.

References

To summarize a couple of pertinent facts from Fundamentals of Geographic Refe4encing Systems and Map Projections: You should never use an unprojected Geographic Coordinate System (GCS) as the coordinate system for a map of any kind. A sutible coordinate system for a map of Mainland Massachusetts would be the Massachusetts State Plan Coordinate System. Choose the Mainland or Island case as appropriate to your study area.

Create a letter-sized,landscape format map layout

Our map is going to be on a letter-sized sheet of paper, landscape format. This layour will help to assure that the map is easy to read either on a print-out, computer screen or projected. Setting this up requires that you set the File > Page and Print Properties.

References

Use Layout Zoom and Pan Tools to Set up your Layout

Having set up your map page size you can set your View properties of ArcMap to Layout View tp work with the placement of the data frame and other page elements onto your sheet of paper. Entering Layout View you wil see that you have a new set of pan and zoom and other tools for navigating on the page, in addition to the pan and zoom tools that you use to navigate witin the map window. The scroll wheel now zooms and pans relative to the sheet of paper.

Arranging your Layout Elements

When you first enter layout mode, your map may not be fitting the paper at all. The first ting you need to do is use the black arrow, also known as trhe Select Opjects tool to click on the map and to resize it by dradding one of the blue handles around the edge. You can move and resize the map window until it fits inside the page with some margin arouind the edges and a larger area for your caption, scale bar and other elements.

Use Map Zoom and Pan Tools to Frame your Context Map

Now to zoom and pan the contents of the map window toframe a meaningful context for your map. To begin with, you should think about the elements surrouinding your study area, that are important to consider. Here are a few considerations:

For example, since our example involves locating new transit stops, our context map shows the location of existing stops in the surrounding area. Since transit users in the study area are headed to Downtown Boston, our context map is shifted so that this important place appears on the map.

Noramlly, your area of cocus wil be near the center of the map. Avoid zooming out too far and including a lot of terriroy that has no relation to your discussion of context. COnversely, if the map is zoomes in too closely to your details, your user may wonder if there is something nearby that might be important.

References:

Use the Pan and Zoom tools on the Map Toolbar to adjust the saale and coverage of your map. Once you have found a good coverage, you can set a bookmark tomake it easier to return to this exact extent.

Save your map.

Arranging the Background of your Map's Graphical Hierarchy

The arrangement of information on a map often uses a Layering metaphor. Map layers have an order in terms of which features may be underneath (obscured by) other layers of features. For example, roads usually occur above water. Water bodies usually are visible above areas that are designated as public open space. Etc. This ordering of layers can be accomplished in ArcMap by draggng them up and down in the Table of Contents. Map layers and their features may also be ordered according to their importance that we assign to them. Adjusting the graphical hierarch of the symbols and layers on your map is a very important way for you as an anayst to manage the limited attention of your audience -- to emphasize the most important subjects while at the same time providing references to specific elements of context that are pertinent, and the general background of features that may be undertood with no coscious effort on the part of the audience.

Leaving the emphasis of your information to chance defaults and letting ArcMap label lots of irrelievant features signals to your audience that either you are confused, or not interested in the context of your study.

References

Adjust Layer Order

    • The ArcMap table of contents has several buttons at the top that control how the layers in your map are displayed. You can hover over them and see that the left-most option is List by Drawing Order to-re-order your layers grapincally, your table of contents should be in this mode.
    • Select layers and drag them up and down to make sure that roads appear "on top of" water and opsn-space, and hydrographic features appear aon top of open-space, etc.
    • I'm not going to tell you exactly what to do here but use your judgement.
    • It is helpful to keep grouped layers closed when you are doing this, unless you intend to drag layers out of or into the groups.

Adjusting Symbol Shades for your Background Layers

The background of your map needs to show the important aspects of context that are essential for understanding the natural, administrative and cultural aspects of context, in a way that can be registed in the mind of the user without a lot of effort. It is helpful to select subtle colors to distinquish water and land, open space, and roads. Since the default color pallette in ArcMap does not have a lot of choices, I recommend choosing a general Hue form the default color panel and then choosing More Colors toadjust the Saturation and Value to dial-back the emphasis of your colors. Whan you have this right, the backgrond of your map wil lhave distinct colors, but none will be darker (value) or more vibrant (saturation) than the others.

References

Simplifying Polygon Layers

Sometimes you may have layers, like the MassGIS protected open-space layer that make a lot of distinctions that are not important or distraxcting. You should avoid distracting your users and raising irrelevant questions such as: "Why are some parks yellow, and others pink?" If these distinctions are not important in your decision-makinf context, you might choose to symbolize all of your open-space polygons with a single green shade. It is probably unnecessary and needlessly distracting to show the boundaries of parks, so you can set the line-weights for the park boundaries to 0.

It happens that our MassGIS Hydrography layers have a very nice hierarchy of shades and textures, so you can leave these alone.

Let your land be Pale Yellow

You should avoid using the color white in the detail area of your map. Plain white should be reserved for the background of things like margins, captions, scale-bars, etc. Therefore, to distinquish land from water, it is helpful to have a polygon that represents land, or using the backgrouind property of your data-frame to shade blank areas with a nice pale yellow that might be interpreted as nice dray land on a sunny day. Fo rour sample map, we can use the shading of our Town polygons to stand for land. But make sure that this layer is below the water. If you want to be fancy, you can drag the town boundaries (a line layer) above the wayer to show town boundaries that run down the middle of rivers, and such.

Controling a Hierarchy of Line Weights and Symbols

Our roads layer uses a lot of bright colors and complicated line patterns to make a lot of distinctions among roads which are probably not as important as other things we may want to emphasize. We can keep some of the distinctions between major and minor roads while simplifying the line symbols and colors to convert the MassGIS symbols to a very simple hierarchy of line weights and line symbols.

References

  1. Drag the layers around to adjust their display order. for example, the Roads layer should be above the Open Space and Water Layers. Water layers should be above Open-Space (usually.) Look around for logical layering peoblems and fix them.
  2. Now adjust the line symbols for your streets so that they do not use too much visual band-width, but stil ldistinguish between small roads, larger roads and tunnels. Remember that you can change the properties for all symbols or select groups of symbols to assign the same color , width or line-type to, say all the tunnels.
  3. The automatic labeling for streets creates a lot of information that is distracting. Right-click your roads layer and un-check Label Features
  4. People expect that open space should be green. You may need to fix this layer to avoid confusing people with pink and yellow parks. No need to show hard edges on polygons like parks.

Preview Symbols at 100% Page Size

When adjusting things like line-weights and (next) font sizes, it is important to have a sense of what these will look like when the map is viewed at the size intended. To do this, you can go to the Layout Toolbar and choose 100% from the Zoom t Percent pull-down menu.

Adding Title, Captions and Other Marginalia

We will leave the map now and focus on the title, caption, scalebar, north arrow and attributions. For titles and other text and potentially for custom-made north arrow, we will use tools from the Draw Toolbar. Scale bars and a selection of ready-made north arrows are available form the Insert menu when you are in Layout Mode.

add the Draw Toolbar

To add the Draw Toolbar right-click an empty spot in the ArcMap manu bar, and choose Draw.

References

Titles and Other One-Liners

To add a title, you can use the simple label tool from the Draw Toolbar. Adding a caption is accomplished with the Box Text tool. The image below shows how these tools are found on the Draw toolbar. A couple of very important style-tips for Box text: Change the Justification to Left-Olny justification, and set the Frame properties for your box text to use No Border.

Your Title and Caption will present a hierarchy of concepts in your decision-making scenario. The tile references the most important things and conditions, and the caption should reference a few things and conditions, like street-names or existing facilities that are useful to know about for a discussion of the situation. Later on we will add labels to the map, and adjust their graphical emphasis.

Adding Text in the Margin of the Map

  1. Look for the Draw Tool bar at the bottom of the ArcMap window. If it is not there, go to Customize > Tool bars > Draw to add it.
  2. Use the Text tool ()to add a title to your map layout.
  3. Use the Rectangle Text tool to add a caption. Note 1: The rectangle text tool can be found in the Draw toolbar by pulling down the labeling options unter the text tool. Note that this works best if you set the text options to justify on the left.

Add and Adjust your Scalebar, North Arrow and Projection Declaration

A good context reference map will have a graphical scelae that makes it easy to infer real-world distances from measurements made on the map, and a north-arrow that points north. It is also expected (on maps at a regional or local scale) that East, and West wil lboth be 90 degrees away form North and South. We understand from our discussion of Map Projections that these map properties are only possible when the geometry of the map is transformed with an appropriate projection. Therefore, it is good cartographic style gropup the graphic scale,and north-arrow together with a reference to the projection case that has been used.

References

Insert a Scale Bar

It is easy to add a scale bar to your map that will provide a quick conversion of distances on your map to actual distances on the ground. (If you have chosen an apprpriate projection for your map,) If you aren't careful, however, the scalebar will be divided into lengths that involve whacky decimal places. Even if you adjust the length of your scale-bar by hand, if you do not set the properties of the bar to Adjust Width when resizing the map, the scale's units will change and become absurd fractions again. Of course, you want your scale to be composed of diviisions that are easy to hold in your head and discuss. You definitely don't want your users to be distracted by this sort of questioniable map details.

Insert a North Arrow

It is easy to choose Insert > North Arrow to add one of the ready-made north arrows to your map. If you don;t like any of these, you can create your own using tools fomr the Draw Toolbar

Declare your Projection

A single one-line projection declaration can be added below the scale bar. It is only necessary to declare the projection case. You do not need to include the earth model or the FIPS projection ID. Click this reference for more details about declaring projection parameters.

Grouping Graphical Elements

Like with most drawing tools it is possible to shift-click to select your North Arrow, Scale-Bar and Projection Declaration and then right-click to Group them all together to make it easier to adjust their location.

Attribution of the Map and Sources

One of your goals as ana analyst is to establish credibility for your map. To achieve this, you need to identigfy yourself as the map-maker and the and the institutional context for the map's creation. In the same block of text you can also provide a A short citation for each of the layers in your map.

Developing your Map's Reference Layer

A huge part of the way that your map and your caption communicate is with labels. If there is a place that is important enough to name in your caption, it should be labeled on the map. If you don't name anyu places in the caption, then that is a problem, too. On the other hand, if there are too many places named on the map that are not part of your discussion, this is distracting an annoying to your map user. When cartographers get together over beers, they always talk about the ways that labels can be associated with the features that they are applied to. Label fonts, colors, size, label placement and label stacking and justification are some of the interesting dimensions of labeling, too numerous to cover in detail here.

Most maps that are presented in an analytical setting should include diagrammatic elements, like markers, lines, shapes and arrows that call attention to the specific area of interest and the real or hypothetical things, conditions and changes that you have specified in your description of your Decision-Making Situation.

To make this discussion easier, we will use the term Annotation for labels and diagrammatic graphics. One of the most common pitfalls that seperate professional-looking maps from maps that are created by untrained GIS jockeys can be seen in maps where annotations are allowed to collide with the linework of the map. Each intersection of annotation challenges the user to sort out the text and graphics. Given the tenuous attention of many users, this difficulty may render your map completely useless as a communication device.

Layered Graphical Hierarchy and Multi-layered Symbols

In the conception of a three-layer graphical hierarchy, annotations are used to reference places that have been named in the text, or that a person would be interested in knowing given the things , conditions and relationships that are of concern. These labels and graphical elements are lifted off of the background by the use of a lighter-colored halo or mask that hugs the label or graphic and eliminates collisions with surrounding lines. Groups of labels and graphics can be adjusted in terms of more or less emphasis or By adjusting the color of the masks. Using a brighter, wider mask raises the annotation higher off the background for greate emphasis. Coloring these with a shade that is similar to the ambient background, the labels can be very legible and there for reference, without calling attention away from your subject.

Working with Auto-Labels

If we have the attention of a person and we wish tocommunicate, it is very important to be concise. A map that includes a cacaphony of needless random is similar to a speaker who has no focus. ArcMap has a sophiosticated labeling function, but it does not understand what labels are important. Labes can be sorted, styled and supressed according to SQL filters, but this is a subject for another day. For the current project, we wil experiment with turning the auto-labels on and off.

Explore Label Properties

  1. >To understand the way labels works, take a look at the Attribute table for the layer Towns Shaded. See that there is an attribute named Town. The values for the attribute Town is a string of upper-case characters corresponding with the name of the town.
  2. Now open the layer properties for the Towns Shaded layer and look at the label properties. These properties are set to label each of the polygons the same way, according to an "expression".
  3. If you open the expression box you will see a bit of code that transforms the upper-case town name into a name with proper capitalization. This sort of label sophistication, provided by MassGIS, is further than most ordinary users go.
  4. To get a feel for the ordinary way of configuring auto-labels, uncheck the Advaced option in the Expression Panel and click OK.
  5. Normally, if a label property is set for a layer, the user has simply selected an attribute column to use as label values for each feature.
  6. If you want to preserve the proper-case function on your towns layer, you can Cancel the layer properties without saving.

Supress Needless Auto-Labels

When working on your map hierarchy, it is helpful to zoom to your map layout, and imagine yourself looking at the map for the very first time. What elements of the map grab your attention first? On my map, it is the road labels that demand the most attention. THere are labels all ofver the place and most of these are completely irrelevant to my subject. Lets turn off auto-labeling on roads and any other layers that may be displaying superfluous labels. To do this, right-click the layer in question, and un-check the option to Label Features. We will add labels for specific, pertinant roads and other features after we learn how to add text to the margin of the map.

Turn Off Auto-Labeling for Roads

  1. Right-Click on the MassDOT Roads layer.
  2. Un-Check Label Features

Creating the Reference Framework

The Background, or bottom of our graphical hierarchy takes care of the ambient context. Another thing that the map should do is answer specific questions that the user may have and to put labels on things that are likely to be part of the discussion. These are aspects of the map that we want the reader to notice. So we will use darker colors and may employ a light background behind the line work and text to pull this reference information above the background.

Our descriptive paragraph establishes that the relationship between Union Square with the cities of Boston, Cambridge and Somerville. Since these elements are essential to our discussion we should name them.

References

Pulling Labels Off the Background, up into the Reference Layer

In policy and design, the location of our project with regard to town boundaries matters. It is important for the analyst and the client to know the names of the town involved so that the context can be discussed intelligently. Town boundaries and labels are important reference information. While these may not be emphasized. the ultimate subject of the map, they need to be pulled off the background and into the Reference Layer of our three-level graphical hierarchy.

Lift Town Labels off the Background

The town labels are difficult to find. They are too small and mixed up with the roads. The next several steps wewill make the labels bigger and brighter and raise them off of the background by dropping a halo behind the labels. Halos are a criticalpart od managing the attention of your map users. ArcMap does not make it easy to set halos behind your labels, but it is worth the effort.

  1. Take a look at the attribute table for Towns. Note that the Name attribute holds the name for each town.
  2. Double-click on the layer and look at the Label properties.
  3. Select Name as the label field, and adjust the font size and weight.
  4. Now for the halo, click the Symbol button then click the Properties button, then click the Mask tab. You can now set the color and the width of the halo.
  5. Sorry that is so many clicks. You could probably figure out a better interface for this and send it as a suggestion to ESRI.
  6. Finally you can click OK until you are back at the map and then right click the Towns layer and choose Label Features.
The automated label placement feature of ArcMap is very convenient, but it does not always place them the way we would like. And in some layers it will place many more labels than we want. Remember that we want to be concise and that means labeling just those elements of the map that are part of our description, or that we may expect to come up in a discussion of our argument. Below, in the section on Placing Text on the Map, we will look at a way of controlling labels more precisely in the next section.

Coordinating the graphical hierarchy of Town Boundaries with Town Labels

Having the town labels is great. But you should anticipate that once the user sees the labels, she will be looking for the boundaries that actually say where the actual distinction between towns takes place. The skillful cartographer is always trying to anticipate questions like this. We can help our user out by using a similar color and halo treatment for the town boundaries., as pictured in following slides.

references:


Developing the Foreground of your Graphical Hierarchy

Up until now most of our graphical choices have been made with an eye toward avoiding attention. This should leave a little bit of bandwitdth to call attention to three or four things conditions and relationships that are named in out descriptive text and also labeled on the map. The techniques for lifting these annotations to the top level of the graphical hierarchy are the same as we used to develop our reference layer, above) but the coors of our labels and diagrammatic figures may be of a brighter hue, and with more saturation and value. And the halos fo rfore-ground annotations may be wider and whiter.

Tuning your Hierarchy

You should get into the habit of tuning your graphical hierarchy by pretending to be a tired, overworked bureaucrat who wonders whether your map is worth the effort to understand. What are the first colors or elements of text that attract or distract your attention? YOu can then supress, or dial-back the intensity some elements, and try to tweak or more carefully direct attention to a few places.

Adding Graphics and Text to the Map

The drawing tool bar can be used to add graphics to the map. This is where we will add a few things that will be on the highest -- Foreground -- level of our graphical hierarchy -- such as the red box and label that identifies our area of interest. We will also add labels for the major roads and the landmarks, etc. -- especially all of those things that we mention in our paragraph. The most important thing to remember if you are making graphics that you want to move and scale with the map, you need to double-click in the map frame so that it grows a hatch around the edge that indicates that graphics that you add are added in Map Space.

References

Lifting Lines and Polygons to the Foreground Using Multi-Layered Symbols

Now we are ready to add the icing to the cake. We need to call attention to the primary subject matter of our argument. Where is Union Square? We will add a red box and a label that identifies our area of focus. We want this label and the box to move if we shift or zoom in on the map. To accomplish this we need to change the focus of the drawing tools to Map Space.

  1. Double-click the data frame (map) in the layout window so that the edge of the map frame becomes hatched, This means that you can add graphics that will move with the map.
  2. Use the polygon tool () to make a box that identifies your specific area of interest, and you can double click it to change its properties (to make it a red outline with no fill. Note that if you pull down the polygon tool you can draw lots of different sorts of shapes including a free form polygon. To stop drawing, dobule-click.
  3. A graphical box like the one we just created will block out any labels that overlap with it. To get around this, you can select the graphic box, and use the technique for Creating Features From Graphics to create a shape file for your area of interest box. When you are in the save dialog, make sure to change the File Type Pulldown from geodatabase feature class to shapefile.
  4. If you want to pull your red box off the map you can change its line symbol to incorporate a wider white line behind the thinner red line. To do this, double-click the red box to bring up its properties. Then choose Edit Symbol Then choose Change Symbol. Here you can use the Layers tool to put a wide white line behind the ref outline which will make the s red boundary appear lift off of the background.
  5. Find the Add Text Tools by clicking and holding the A on the Draw Toolbar. You can then add a label identifying this box as Union Square.
  6. Double-click your label to edit its properties. Here is where you can make it red. If you choose Change Symbol then Edit Symbol, under the Mask tab, you can change the Halo settings to put a white halo around your text to make it raise off the map.
  7. When labeling things like streets, you may want to use text halos as discussed above, but these street names should not be emphasized as much as your area of interest box. By changing the brightness of the halo and the darkness of the ext you can fine-tune the amount of attention these elements consume.
  8. Another useful tip for labeling linear features like streets is to rotate the labels or use the Align Labels to Curve tool (with the rest of the text tools in the draw toolbar) to better associate the label with the thing that is being labeled.
  9. Before making a lot of labels that are the same, It can be useful to select Default Symbol Properties from the Draw tool bar menu to set up the kinds of line, text and point symbols that you plan to use. This way you don't have to set the style for each one. Also note that labels can be rotated or even laid along a curvy line.

A legend? In these general context maps it is best to stick with portrayals that follow basic conventions of Symbology. Water should be blue, protected open space should be green, roads should be displayed in a graphical hierarchy. IN this case there is no need for a legend. But since you will use this same framework for thematic maps later, you should leave room for a legend in your layout.

Saving the Map Document

Now we are almost done. We will save our map document -- since this has been a lot of work and you can rest assured that we will want to revise it later. Make sure to save the map document in the docs folder of the data collection. Use the Source view of the table of contents to make sure that all of the data referenced are underneath the same folder that also contains the document.

References

  1. Set your Table of Contents to Source mode and double check that all of your data is in the same folder tree with the data that it references.
  2. Check the File->Document Properties->Data Source options and make sure that you are using relative path names as discussed in the tutorial beginning a GIS Database
  3. Create a folder for yourself within the GIS Tutorial folder. Within this folder make a folder named map_docs. Save your map document to your map_docs folder. Give it a name that ends with _1 so that you can save incremental versions.

Exporting your Map to JPEG or PDF

ArcMap documents are good for exploring data and authoring graphics but not great for sharing graphics. TO do this we will want to be able to save our maps to jpeg files or pdf or other formats that can be opened in Acrobat Reader or desktop publishing applications like illustrator. In this, you should be able to adjust the various options so that you can control your resolutions and avoid common problems with fonts.

References

  1. Look at the File>Export Map options for exporting your map as a jpeg. Notice that you can adjust the DPI.
  2. Export your map as a PDF. Check the export options to see that you can embed your fonts. This is a very important thing to do, otherwise your special map fonts may be converted to gibberish your maps are viewed on a computer without ArcMap installed.
  3. Open your new map in Acrobat Pro. Note that you can use Document>Insert Pages to build a pdf document with multiple pages. You can use Microsoft word to add title pages, and bibliographies, etc.

Bonus Topics

Add An Inset Map?

It can be useful to add a small inset map that reveals the extent of your detail map within a greater region. This can be accomplished by adding a second data frame to your map document and adding it to your layout. You can set the Extent Indicator property of a data frame so that it shows up as a box in the other, as described in the references below.

Once created, additional data frames are added to the layout from the Insert menu.

References