Creating contours on DEM layers (Defense Mapping)

Contour creation involves several steps that define the way the contours are generated and where the feature class is stored. You must specify a name for the contour feature class that is generated, the interval for the contours, and the database in which the layer is stored.

When the contour feature class is created, some attributes are added and automatically populated based on the fields defined using the Contour Field Options tool. They include the fields that contain the feature code, contour type, and elevation value attributes. The feature code attribute is automatically populated with CA010, and the contour type attribute is populated with a value of 1 for index contours and 2 for intermediate contours.

Remarque :

You must have the Extension ArcGIS Spatial Analyst enabled to perform this task. For information on enabling the Extension ArcGIS Spatial Analyst, see Enabling the ArcGIS Spatial Analyst extension.

Remarque :

The smaller the interval, the longer it takes for the contour feature class to be generated, because more contour lines will be created.

Etapes :

1. Start ArcMap.
2. Load the DEMs files you want to filter.
3. If necessary, load data in the map.
4. On the main menu, click Customize > Toolbars > Production Contouring.
5. Click the Create Contours button on the Production Contouring toolbar.

   The Create Contours dialog box appears.

   Remarque :

   The Applicable Layers list displays the names of the DEMs that will be used to create contours. A contour feature class is created for each DEM listed. Turn off the visibility of any DEM that you do not want to create contours for in the table of contents.

6. If necessary, type a value in the Base Contour text box.

   The base contour value is the height from which all contours are created, both above and below the interval you specify.

7. Type a value in the Contour Interval text box.

   The contour interval is the frequency in which contours are generated from the DEM.

8. Click the button next to the Geodatabase Output field.
9. Navigate to the geodatabase you want to use to save your data and click Open.
10. Cliquez sur OK.

Astuce:

A new contour layer is generated for each DEM layer. The format of the layer name is root name + parent directory + identification number.