Lab 2: Creating Map Displays

1

Introduction: Choosing how to communicate the meaning of a map may be one of the most important decisions a spatial analyst can make. Composing an effective map requires a component of artistic expression as well as familiarity with proven cartographic norms. A design that is visually pleasing will more easily catch the attention of your audience and give you an opportunity to convey your message. This can be a challenging task. Your goal is to convey concise information about the real world at extremely reduced scales. This can be achieved through the careful use of symbology to represent features on the earth. The table below highlights the various GIS symbol types and their appropriate alterations to aid in effective communication.

For many years cartographers have been studying the science and art of creating effective map layouts. For our purposes, we will focus on a basic set of cartographic principles that includes balance, hierarchy, figure/ground relationship, and visual contrast. Balance is the organization of map elements (data frame, north arrow, scale, etc.) in a fashion that limits the creation of large open spaces on the layout. Hierarchy is the established sequence of importance of the map data elements; care should be taken to assure that the most important elements ‘stand out’ in relation to the others. The figure/ground relationship is the ratio of figure (the to-be studied or important mapped data) to the ground (background or unimportant mapped data); too much of either and the map will begin to lose its meaning. Finally, the visual contrast is set to assure that the elements or objects of your map are distinctly different from the background information. Each of these compositional elements directly affects the legibility, or clarity, of your map. Shape, size, position, hue (color), value (darkness), pattern, and symbology are altered to control the basic design principles. More information about these and other principles of map composition is available online: • The Geographer’s Craft (University of Colorado):

http://www.colorado.edu/geography/gcraft/notes/cartocom/cartocom_f.html Under “Section 4. Basic Elements of Map Composition”

• Introduction to Map Design (ESRI): http://www.esri.com/industries/k-12/education/~/media/files/pdfs/industries/k-12/pdfs/intrcart.pdf

Page 16 - "Map Composition" • Map Design (Borden D. Dent: Cartography – Thematic Map Design, 5th ed. Ch 13)

http://www.geog.nau.edu/courses/rh83/pl431/workbook/MapDesign.PDF Learning Objectives:

ESRI, GIS Day Materials

Lab 2: Creating Map Displays

2

• To understand a set of basic cartographic principles

• To explore the tools within ArcGIS that will help achieve those principles

• To develop an ability to communicate through maps

To be submitted:

1. (10 pts) A write-up answering the questions throughout the lab. Include as many graphics as necessary to illustrate your answers. (500 word maximum, 12pt font, 1.5 spacing)

2. (10 pts) A map layout that adheres to the cartographic principles detailed above. Overview: To explore the concepts of mapping presented in lecture and described above, you will be provided three data sets (roads, land use, & places) for Washtenaw County, Michigan (home to UM). You will prepare a general reference map that displays Land Use and Population Centers (LUPC) in Washtenaw County, following the steps outlined in the lab. The purpose of this map is to provide a general overview of the land-uses in relation to the population centers within Washtenaw County. In addition to providing general reference, you will choose a more specific target audience and purpose for your map. Be sure you are clear about what is to be communicated and adjust the various cartographic elements to achieve this goal. Procedure: 1. Download the lab2 data from Ctools and unzip into your lab2 directory, remember to create

a “lab2” directory within your M:\gss777 drive space. Remember: No spaces in file names. 2. Connect to your working directory via ArcCatalog. 3. Add data to ArcMap: With the skills you have acquired from the previous lab, add the

Roads (roads_utm), Land Use / Land Cover (land_utm), and Washtenaw Places (wash_places) shapefiles to ArcMap.

4. Defining the appropriate symbology The procedure below details how to set the symbology for the polygon layer, land_utm. You will then be instructed to set the symbology for the line and point layers (roads_utm & wash_places) in a similar fashion. • Right-click on the land-use layer (land_utm) from

ArcMap’s table of contents and select ‘Properties’. • Choose the ‘Symbology’ tab; from here you will be able

to alter the display symbology for the associated shapefile.

• From the ‘Show’ box on the left, select ‘Categories’| ‘Unique values’. This will allow a unique color to be displayed for each attribute label.

Lab 2: Creating Map Displays

3

• The ‘Value Field’ selector will allow you to define which attribute you would like the symbology to be displayed upon – choose LAND_USE. Uncheck the <all other values> box and click the ‘Add All Values’ button to fill the

symbol column with the available categories from the Land_Use attribute. Select a Color Ramp that you think best represents each land-use category. Click

‘Apply’ and ‘OK’ to continue. • If, upon display in ArcMap, the colors do not logically match the land-use labels or are not

distinguishable enough from one another, right or left click on the symbol color in the table of contents and adjust accordingly (try both as they allow different options). By selecting ‘more colors’ at the bottom of the color options window, you can access the HSV sliders, which allow you to change hue while holding value and saturation constant, or change value while holding hue constant. You may also want to alter the symbology color ramp again.

• Verify the legibility of your symbology choices in ArcMap. • If you believe there are too many categories or colors being displayed, you have the option to

merge the various categories into aggregated groupings (for instance: forested, agricultural/open, residential, commercial, transportation, and hydrology). To accomplish this, return to the symbology tab in Properties, left-click (while holding down the ctrl key) on the symbol for each of the categories to be aggregated, right-click on one of them while all are still selected, and choose ‘group values’, then adjust the label (e.g., forested) to better represent the newly formed class.

A few useful tools for designing color schemes: • A user-friendly tool specifically designed for mapping: http://www.colorbrewer2.org • Another useful tool for picking color schemes is the Adobe Kuler website:

http://kuler.adobe.com/#themes/rating?time=30 • To see how your colors will be perceived by color blind people:

http://www.internettg.org/newsletter/mar99/color_challenged_table.html Or download a free color-blindness simulator: http://color-oracle.en.softonic.com/download

Question 1 (4 points): Briefly define the three components of color (hue, value, and saturation). In what situations would it be best to hold value constant and vary hue to differentiate map categories? In what situations would it be best to hold hue constant and vary value to differentiate map categories? How did you come up with a color scheme for your land use categories (which components did you choose to vary and which did you choose to hold constant and why? What other considerations affecting your color choices?) (Note: this should reflect your answer to Q3). Repeat the procedure of adjusting symbology for the roads_utm data. Use IGDS_LEVEL as the attribute based on which to display. Choose appropriate colors and line widths for the road network that will help establish location within the county, but not distract the viewer from the main focus of your map.

Set the symbology of the final component of your map, wash_places. For this layer, you are interested in two aspects, location and population; you will need to adjust your symbology to account for both. • Open the ‘Properties’ dialogue for wash_places

point and click the ‘Symbology’ tab.

Lab 2: Creating Map Displays

4

• From the ‘Show’ box, select ‘Quantities’ | ‘Graduated symbols’. This will allow you to increase the symbol size for the cities as the population grows.

• Specify A1990 (Population from 1990) in the ‘Fields Value’ box. • Choose a from/to symbol size for the display. This will set the minimum and maximum size

for the symbol graduation in your layout (it may take several selections, viewings, and reselections to find the symbology you are most comfortable with).

• Classify the data using Natural Breaks, Equal Interval and Quantile methods. To do this, click on the ‘Classify’ button in the ‘Classification’ box. Select up to 5 classes to break up your data. Completing the table below may assist you in describing the differences between the three methods (for your reference only; do not include this table in your write-up).

Classification Method Natural Breaks Equal Interval Quantile Break value 1 Break value 2 Break value 3 Break value 4 Break value 5 • Choose a Classification method and number of Classes that best describes your data. Use

the Help system to decide which of these would be most appropriate for you. Select the number of classes you wish to use to break up your data (again it may take several selections, viewings, and reselections to acquire the symbology you are most comfortable with).

• Once you have selected a classification scheme, it is usually a good idea to round off the values of each category. Round aggressively to avoid a map legend that has too much detail to be easily read. You can change the value ranges manually by left-clicking on a value range (under ‘Range’ under the Symbology tab) and typing in the upper limit of that range. Click OK.

• Adjust the symbol type and color by left-clicking on the symbol in the table of contents. Be sure that the symbol’s type and color make it clearly distinguishable from the other map features. You should also verify that the relative sizes of the cities are reasonable. To accomplish this, check the actual population (try using the “Identify” tool shown on the next page) of, say, Ann Arbor vs. Dexter vs. Ypsilanti. If Ann Arbor is twice as populated as Dexter, the symbology should reasonably represent this. Based on the data you have, the figures will never match exactly; choose a method which best represents the population differences.

Question 2 (3 points): Which classification method, and how many classes did you end up using to display your population data? Why did you select that method? Why does it matter which classification method you select? (Note: this question is independent of Question 3. For example, even if your answer to Question 3 indicates that population is not important to the viewer, for this question you should think about how population would best be represented in a general reference map).

Lab 2: Creating Map Displays

5

Question 3 (3 points): Based on the data provided, choose an audience and purpose or message for your map. Explain who will be viewing your map and what is the most important or interesting thing you want them to learn from it. (It is not enough to say that the viewer will understand the distribution of land covers and location populations – what will they learn about distribution of land covers, population, etc.?). What choices did you make in designing the map that led the map reader to this understanding? (Do steps 5 & 6 with your audience and purpose in mind, and then answer this question after). 5. Adding additional map elements

In this section you will add additional map elements to the page layout, for example: north arrow, scale, legend, title, and sources. • From the ‘View’ pull-down menu in ArcMap, select

‘View’ | ‘Layout View’ or use the icons located at the lower left of the map display.

NOTE: If your Layout View screen “freezes” and you cannot make changes to the page, click off of the layer frame in the blank white space to the side. This will remove the hash mark box around the layer frame and you may begin making changes again. North arrow • From the ‘Insert’ pull-down menu in ArcMap, select ‘Insert’ | ‘North Arrow’. • This will bring up a north arrow selector, choose your favorite one and click ‘OK’ • Move and resize as desired. • It is possible to set a ‘calibration angle’ for the north arrow in the north arrow selector, or in

the north arrow properties (right click an existing north arrow). The calibration angle rotates the north arrow a specified number of degrees, for cases when the north arrow needs to be offset (not in this lab).

Scale bar • From the pull-down menu in ArcMap, select ‘Insert’ | ‘Scale Bar’ • This will bring up a scale bar selector. Choose your favorite one and

click ‘Properties’. • From this menu you will need to define the number of divisions,

subdivisions, and the division units – think about what your map is going to represent (an entire county) and choose the most appropriate units.

• Adjust the length of the scale, so the values are appropriate. It is best to have round numbers at the end (e.g. 1, not 1.2)

• Each of these changes will drastically affect the appearance of your scale; apply the changes, view them in ArcMap, make any alterations you deem necessary by right-clicking the scale and opening ‘Properties’, view changes again, repeat as needed.

• Move the scale to a location that you think is most appropriate.

Scale text • As an option, you have the ability to add a Scale text to your layout as well – the procedure is

similar to above. Go to ‘Insert’ | ‘Scale Text’. Use the “absolute scale” found in ‘Properties’ and select ‘Absolute’ in the ‘Style’ box. After inserting the scale text in your map change the

Data Layout View View

Lab 2: Creating Map Displays

6

map scale pull-down menu (located in the toolbar) to an appropriate round number (i.e. 1:323,222 could be changed to 1:320,000, or better 1:300,000), hit the enter key to commit your changes. Make sure to minimize open space on your layout.

Legend • From the pull-down menu in ArcMap, select ‘Insert’ | ‘Legend’. • The legend wizard will appear. The first window allows you to specify to display only the

legend items that have data visible on the map. This is useful if your focus is on a subset of a large dataset that is void of many of the feature layers contained in your data view. Choose the layers you wish to incorporate into your legend. By default the legend appears as one vertical column. If you would like the legend to be more horizontal you may increase the number of columns. Change the column number to 2 and click the Next button.

• Accept the defaults for the remaining legend wizard windows, but take note of how these windows allow you to manipulate your legend; you will need to use them in the future.

• Later, you can modify the design of your legend and its items (e.g. spaces, columns, titles, legend fonts) by right-clicking on the legend, selecting ‘Properties’, and adjusting the appropriate parameters.

Title • From the pull-down menu in ArcMap, select ‘Insert’ | ‘Title’ • Enter the desired title for your map (be sure to think of the purpose of your map layout) and

click ‘OK’. • Drag the title to the most appropriate location for your layout.

Source information • From the pull-down menu in ArcMap, select ‘Insert’ | ‘Text’ to add a source of information

set to your layout. • The box will appear very small in the middle of the page. • Drag the text box to the desired location. • Right-click on the text box, select ‘Properties’, enter the desired source information (the

source of these data are: Environmental Spatial Analysis Lab, University of Michigan). Be sure to include your name, your section, and the date, as well. Note: The source information and your information should be clearly labeled as separate. Example from the map shown later in this lab: Source: Environmental Spatial Analysis Lab, University of Michigan Layout: Name, sections, date

Labels • Finally, add names of the cities to your layout: • To ask ArcMap to auto-label the cities based upon a field in the attribute table, right-click on

the wash_places in the table of contents and select ‘Properties’. • From the ‘Properties’ menu, select the ‘Labels’ tab; it is from here that you will be able to

specify the type, placement, and any other label rules you would like to set. • Within the labels tab, check the box signifying that you wish to label the features in this

layer. Specify the Label Field as PLACENAME (this is the attribute containing the names of the cities).

• Specify a symbol and label placement option of your choice – Click ‘Apply’ and ‘OK’ to continue. This also may take several tries to feel comfortable with your settings.

• (Challenge: Can you figure out how to put a white halo around your place names?)

Lab 2: Creating Map Displays

7

Basemap (optional) ArcGIS provides a set of themed basemaps accessible through ArcMap. Themes include imagery, street maps, and topography, among others. • To view these basemaps, select ‘File’ | ‘Add data’ | ‘Add Basemap…’ Alternatively, click

the down arrow next to the “Add Data” button on the standard toolbar and select ‘Add Basemap…’

• This opens the Add Basemap window, which displays available basemaps. Be aware that

adding a basemap may slow down the performance of ArcMap, and that adding any of these basemaps will automatically add an ESRI watermark to the dataframe in the map layout.

Final Layout Modifications At this point of the process you need to be concerned with final adjustments of your layout. You should pay attention to the font type, size, and color. Also, this is the point when you should be sure the design principle of balance is achieved. There is a suite of alignment tools to assist in this task as you will see below. The text symbology can be modified for each of the elements (legend, title, text, scale bar, etc.) you have added to your layout. • To do this, right-click on the element and select ‘Properties’. • Within each there should be a ‘Symbol’ or ‘Change Symbol’ button; selecting this will launch

the symbol selector menu. From here you can adjust the size, color, and style of the text. • To further modify the text properties this menu also has an ‘Edit Symbol’ button – From

here you can alter alignments, offsets, as well as several other text properties.

Lab 2: Creating Map Displays

8

Use alignment tools to position layout elements. • Find the rulers, guides, and grid tools by right-clicking in a

blank area of your layout (outside of your layout frame) to get the menu shown to the right.

• Experiment with these tools to understand what each does. • You can change the settings for these tools by clicking on

‘ArcMap Options’ at the bottom of the menu and selecting the ‘Layout View’ tab.

The page orientation can be modified • By going to ‘File’| ‘Page and Print Setup’ and changing the Orientation from “portrait” to

“landscape” or vice-versa. Two basic map layouts are seen below.**

** Layout points of note: In both maps, the data element is and always should be as large as possible. The left example constrains the data element on the east and west; the right is constrained on the north and south. An attempt is made to provide as much balance as possible while minimizing white space. Notice though that the other elements are not enlarged to fill white space. White space is ok if there is no other option. The scale, north arrow, and source should generally be found together. Finally, ensure that the data have high contrast; they are very legible with no blurring or confusion between data sets. The left example is the better choice for displaying the Big Island of Hawaii because it allows a more balanced page layout. These are the types of concepts your maps will be graded on over the semester.

Lab 2: Creating Map Displays

9

6. To submit (3 questions and a map): Map to Submit (10 points): In preparing your map, you will decide what use it will serve and/or what message it should convey given the data provided. The presentation of your map should reflect your answer to Question 3. The map must include general reference information on land-use, population, and roads, but the appearance of each layer and its features is to be determined by you to best serve your purpose. Keep in mind that you must use the full extent of your data layers (e.g. you can’t zoom in to show just one city), and you must show at least six distinct categories of landcover (e.g. you can’t group all the landcover categories together under one symbol). Be sure to adhere to the cartographic principles detailed in the Introduction Section and include the layout elements discussed throughout the lab. Note: map color schemes will appear differently on the computer screen than they will as a printed map. Always be sure to test how your color choices will print if you need to turn in printed materials for a job or future class project. It will benefit you to go over your first map with your instructor prior to turning it in. --End Lab2