10.2 Map Surround Elements & Dynamic Text

10.2 Map Surround Elements & Dynamic Text

A well-designed map relies on marginalia—the surround elements that accompany the map display—to guide the reader's interpretation. Map surround elements provide essential context, quantitative spatial measurement, directional orientation, and authoritative metadata. In ArcGIS Pro, analysts can add, format, and align surround elements such as legends, scale bars, north arrows, titles, graphic callouts, and dynamic text blocks to create clear, self-explanatory cartographic products.

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Legends: Configuration, Formatting, and Filtering

A Legend decodes the cartographic language of a map by relating visual symbols (colors, line weights, point icons, hatch patterns) to their corresponding attribute feature classes and data categories. Inserting a legend from the Insert tab links it directly to a designated Map Frame.

Legend Items & Patch Customization

In the Element pane under the Legend Items tab, analysts can control which feature layers appear in the legend. Layers can be toggled on or off independently of their map view visibility. Customizing legend patches alters the geometric shape used to represent features:

• Patch Shape: Line symbols can be displayed as straight lines, horizontal waves, or zig-zags; polygon symbols can be shown as rectangles, rounded rectangles, or natural flow shapes.
• Patch Size & Spacing: Adjusting patch height, patch width, and item spacing prevents crowded legends and enhances visual legibility.
• Label Formatting: Analysts can show or hide layer headings, group labels, and feature attribute descriptions, customizing font size, style, and text wrapping across multiple columns.

Advanced Legend Filtering Options

ArcGIS Pro includes powerful dynamic filtering capabilities that keep legends relevant and concise:

1. Only show features visible in the map extent: Toggling this setting filters the legend so that legend items only appear if their corresponding feature class categories actually occur within the current spatial extent of the linked map frame. If a map is panned away from a wetland area, the wetland legend entry automatically disappears.
2. Show Feature Counts: Appends the exact count of visible features in the map extent to each legend item (e.g., Bridge [14] or Hospital [3]).
3. Visible Scale Range Filtering: Automatically suppresses legend items for layers that are currently turned off in the map due to scale-dependent visibility settings.

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Scale Bars: Units, Division Values, and Fitting Options

A Scale Bar provides a visual metric for estimating real-world ground distances on a map layout. Because scale bars scale proportionally alongside the map frame graphics, they remain accurate even when printed documents are resized or photocopied.

Units and Divisions

When inserting a scale bar from the Insert tab gallery, analysts specify:

• Map Units: Imperial (Miles, Feet), Metric (Kilometers, Meters), or Nautical Miles.
• Divisions & Subdivisions: Major division values (e.g., 10 miles) dictate primary hash mark intervals; subdivisions break down the first division into smaller units (e.g., 2-mile increments) for fine-grained measurement.

Scale Bar Fitting Options

When a map frame's scale changes, or when the scale bar element is manually resized on the layout canvas, its fitting strategy dictates its resizing behavior:

• Adjust Width (Default): Holds the division value constant (e.g., 5 km) and expands or shrinks the physical length of the scale bar graphics on the page.
• Adjust Division Value: Keeps the overall physical width of the scale bar element on the page fixed and recalculates rounded, clean division numbers (e.g., changing from 5 mi to 10 mi).
• Adjust Number of Divisions: Holds the division value and element height fixed while adding or removing division segments as space permits.

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North Arrows & Directional Declination Standards

A North Arrow indicates the directional orientation of the map. When inserting a north arrow, ArcGIS Pro links it directly to a Map Frame so that if the map view is rotated, the north arrow automatically rotates to reflect the true direction.

North Reference Standards: True, Magnetic, and Grid North

In cartography, "North" can refer to three distinct directional baselines:

• True North: Points along lines of longitude (meridians) directly toward the geographic North Pole (earth's rotational axis). True North is the standard baseline for navigational and topological mapping.
• Magnetic North: Points toward Earth's shifting magnetic north pole, as indicated by a magnetic compass. Magnetic North varies by geographic location and changes over time due to geomagnetic field drift.
• Grid North: Points northward along the vertical grid lines (Y-axis) of a projected coordinate system, such as Universal Transverse Mercator (UTM) or State Plane Coordinate Systems. Except along the central meridian of a projection, Grid North differs slightly from True North due to map projection convergence angle distortion.

Analysts select the appropriate North reference type in the North Arrow properties pane. For navigational charts, showing a magnetic declination diagram (illustrating the angular offset between True, Magnetic, and Grid North) is essential.

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Dynamic Text & Arcade Integration

Static text boxes require manual updates whenever project details change, introducing risks of typographic errors or outdated metadata. Dynamic Text solves this by inserting self-updating text tags that query project properties, map frame parameters, system environment variables, or Spatial Map Series index values.

Standard Dynamic Text Syntax

Dynamic text uses XML-like tag syntax inserted into a text graphic block:

• Map Scale: <dyn type="map" name="Main Map" property="scale" preRef="Scale 1:"/> automatically displays Scale 1:24,000.
• Spatial Reference: <dyn type="map" property="sr"/> populates the projected coordinate system name, datum, ellipsoid, and linear unit details.
• Project & System Info: Tags such as <dyn type="project" property="name"/>, <dyn type="user" property="name"/>, and <dyn type="date" format="MMMM d, yyyy"/> automatically display the project file name, current operating system user, and export date.

Arcade Tags in Dynamic Text

ArcGIS Pro supports inserting ArcGIS Arcade expressions directly inside dynamic text blocks using the <dyn type="arcade" expression="..."/> tag. Arcade allows analysts to format numeric attribute strings, calculate areas dynamically, perform string manipulation, or evaluate logical conditional statements (e.g., displaying APPROVED in green text if a parcel status field equals 1).

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Element Alignment, Grouping, and Layering Tools

Maintaining visual organization across dozens of layout elements requires systematic layout management tools accessible from the Format and Layout tabs or the Contents pane tree view.

Grouping and Z-Order Layering

• Grouping: Multiple selected elements (e.g., a title string, subtitle, and municipal logo graphic) can be combined into a single Group Element (Ctrl + G). Grouping allows analysts to lock relative internal spacing and move or scale the combined assembly across the canvas as a single entity.
• Z-Order Arrangement: Layout elements exist in a vertical stacking order. Analysts control overlapping elements using Bring Forward, Bring to Front, Send Backward, and Send to Back commands, ensuring background color frames remain behind map frames and text overlays remain on top.

Alignment and Spacing Tools

When multiple layout elements are selected, alignment tools ensure precise graphic balance:

• Alignment Commands: Align Left, Align Center, Align Right, Align Top, Align Middle, and Align Bottom align selected element bounding boxes relative to one another or relative to the page margins.
• Distribution Commands: Distribute Horizontally and Distribute Vertically equalize the whitespace gaps between three or more adjacent layout elements.