Editing GIS Data¶

Various on-screen editing functionalities are available for modifying or adding features.
Basic editing functionalities are described below.

Editing feature geometry¶

Description	Illustration
The geometry of GIS feature classes (vector data) can be edited using on-screen editing functionality. All editing functionality is available through the edit toolstrip which can be enabled in the data view setting setting list.
To edit a feature class first select the “active layer” from the pull-down menu. In the example two feature classes are added to the Map View and the feature class “Countries” are selected as active layer
In order to edit first bring the active layer in “Edit mode” by selecting the Start Editing button.
During editing you may save edits using the “Save edits” button
Once editing is complete the edit process is terminated using the “Stop editing” button. If current edit session has edit, when stop editing user is asked whether to save the edits.
Editing is done on the map by selecting (clicking) and subsequently modifying individual features. To modify existing features click “Edit features” (this is the selected by default when starting to edit)
To edit a feature simply click the feature on the map. This will enable editing of all points on the feature.
Use the edit handlers on the screen for rotating, scaling or moving the entire feature (all points on the feature).
You may zoom in/out and pan during editing using the navigation buttons in the tool bar.
Click and drag to move individual points.
Click on the feature border (line) to add new points.
Press “Stop editing” to save edits and leave Edit mode.

Description	Illustration
Choose “Sketch new feature” to add new features to the feature class.
Sketch the feature by adding individual points and finish by double-clicking.
Press “Stop editing” to save edits and leave Edit mode.

Description	Illustration
Feature class attributes can be edited using a Data table view. To activate the data table right click on a feature and select “Add to data table …”
Attribute values can be edited directly in the data view. Once a field is edited changes are saved using the “Save” button. The table data view contains functionality for undo-redo (until last save) for cutting and pasting and for sorting and printing.
Attribute values can be copied and pasted into the spreadsheets (spreadsheet manager or excel) where data can be manipulated and pasted back into the data table.
Synchronized attribute table and map selection. Multi select by “shift + click”

Description	Illustration
Attributes can be added to a feature class or removed from a feature class attribute table. To edit attributes select a feature class and choose “Edit attributes” from the context menu.
Add or remove attribute fields as desired.

Description	Illustration
Clip features removes everything located outside a user-specified region. To use Clip features select the active layer and select “Edit”
Digitize the region on the map and end by double-clicking.

Description	Illustration
Erase features removes everything located within a user-specified region. To use Erase features select the active layer and press the “Start editing” button.
Digitize the region on the map and end by double-clicking.

Description	Illustration
Split features splits any features along a user defined line. To use Split features select the active layer and press the “Start editing” button.
Digitize the split line on the map. End by double-clicking.

Description	Illustration
Merge features combines two or more selected features into one feature. To use merge features select the active layer and press the “start editing” button.
Select features to be merged using any othe selection methods described previsouly. Multi-select via “shift+click”.
Choose Merge features.
Attributes for one of the selected features will be assigned to the new (merged) feature. Select the feature holding the attributes to be used for the merged feature.

You can delineate catchments and trace rivers using a raster representing elevation values (called a digital elevation map, or DEM).

Description	Illustration
First, add the DEM to the map, and select the DEM layer from the catchment delineation toolbar. Once you have selected the DEM, the catchment delineation engine (program) will be initialized. This can take several minutes for larger DEMs. Once the initialization is complete, two new layers will be added to the map to display the rivers and catchments that will be delineated from the DEM. These are named after the DEM layer with the words “Rivers” and “Catchments” added to them.
Click on the Trace River toolstrip tool.
On the map data view click at the upstream end of the river you want to trace. This will add a river to the river feature class.
Once you have added at least one river, you can delineate catchments by clicking on a river. The catchment flowing down to that point in the river is then delineated. Remember to save the rivers and catchments layers to the database. You can save them to the database at any time. (See the To Database tool in the “GIS Tools for vector data processing” section below.) Tip: You can use the delineated catchment features to calculate zonal statistics of the elevation or other raster in the database. See Zonal statistics tool strip in the “Working with the Map Data View” section.