Contour lines are often represented by many individual line features, which can result in many more labels being placed than necessary. To avoid this problem, line features that represent contours can be treated as special types of line features. The Maplex Label Engine groups the segments of contour features, if the symbology and label match and the features are connected, and treats them as single, long features. This allows labels to be placed for the contour as a whole rather than for each segment. Contour labels can be aligned in ladders where the label will appear to step up and step down the contours in a straight (or curved) path. These ladders can be created with labels from multiple label classes. The contour labels can be aligned to the page, ensuring that the label is never placed upside down, and also aligned to the contour elevations so that the top of the label is always facing uphill.
There are three placement positions for contour features: Centered horizontal, Centered straight, and Centered curved.
You can also set the contour labels to repeat along the length of their feature.
The following index contours have been labeled using the Centered curved placement position and aligned in ladders. The labels have had halos added to mask the underlying contour feature.
- Ensure the Maplex Label Engine is enabled.
- Ensure Labeling is the active way of displaying the Contents pane.
- Select a label class in the Contents pane and click the Labeling tab.
- On the Labeling tab, in the Label Placement group, click Label Placement Properties .
- On the Labeling pane, click Position and click .
- Expand Placement.
- Choose Contour placement from the line label placement style drop-down list.
The label position can change when you choose the Contour placement style. This is because there are three placement positions for contour features: Centered horizontal, Centered straight, and Centered curved.
- Optionally choose a different label placement position for your contour features.
- Optionally choose a Label alignment option. The contour labels can be aligned to the contour elevations so that the top of the label is always placed uphill. This option allows the labels to be placed upside down. The contour labels can also be aligned to the page, ensuring that the label is never placed upside down. The Page label alignment option is the default. When placing labels using page alignment, you can enter a maximum label angle over which a label will not rotate.
- Optionally click Place labels in ladders. Placing labels in ladders will place the label so it appears to step up and step down the contours in a straight (or curved) path. These ladders will run from the top of a hill to the bottom, will not cross each other, will belong to a single slope, and will not cross any other slope. The Place labels in ladders option is on by default.