For this exercise please use QGIS version 2.18.

Various vector layers and tables (OGR, SpatiaLite, PostGIS, MSSQL Spatial or Oracle Spatial) can be edited in QGIS.  Before you start a editing session in QGIS, make sure you set the right snapping options (Snapping Tolerance and Search Radius). In QGIS you can find these options in Settings > Options > Digitizing or in Settings > Snapping Options. This will optimize the editing process of the layers.

3

Make sure you check the Default snap mode to > Vertex and segment.

For Default snapping tolerance and Search radius for vertex edits select a value and from the drop down menu set the values to map units. After you set these parameters you can proceed with your edit process.

In order to start editing a vector layer the next steps are recommended:

  • Select the vector you wish to edit by clicking it.
  • Go to Toggle Editing and start a new edit session.

4

  • Activate the Advanced Digitizing toolbar. Go to View > Toolbars > Advanced Digitizing Toolbar. The new toolbar is opened.

6

7

Using the basic editing tools you can perform operations like:

Icon Purpose Icon Purpose
allEdits Current edits toggleEditing Toggle editing
capturePoint Add Feature: Capture Point captureLine Add Feature: Capture Line
capturePolygon Add Feature: Capture Polygon moveFeature Move Feature
circularStringCurvePoint Add Circular String circularStringRadius Add Circular String By Radius
nodeTool Vertex tool Delete Selected
editCut Cut Features editCopy Copy Features
editPaste Paste Features saveEdits Save layer edits

The Advanced digitizing and editing tools enhance the capabilities of QGIS performing operations lik

Icon Purpose Icon Purpose
cad Enable Advanced Digitizing Tools tracing Enable Tracing
undo Undo redo Redo
rotateFeature Rotate Feature(s) simplifyFeatures Simplify Feature
addRing Add Ring addPart Add Part
fillRing Fill Ring
deleteRing Delete Ring deletePart Delete Part
offsetCurve Offset Curve reshape Reshape Features
splitParts Split Parts splitFeatures Split Features
mergeFeatAttributes Merge Attributes of Selected Features mergeFeatures Merge Selected Features
rotatePointSymbols Rotate Point Symbols offsetPointSymbols Offset Point Symbols

Lets try a few of these tools and see how they work.

For example if we want to split an polygon (in our case an area represented by a protected area), after a certain limit (a administrative unit limit) we will proceed and use the Split Features tool along with Trace tool. The polygon will be split in 3 parts according to the next image.

8

7

Clicking on the Trace and Split Features buttons and having the snapping tolerance set we can proceed and split the polygon according to the administrative limits.

9

With the trace tool activated follow the administrative unit limit.

10

11

12

13

At the end you should have three separated polygons. Each polygon was split according to the administrative area.

Quality training taught by professionals

RECOMMENDED COURSE

QGIS Adavanced Level