Area qgis意思

"Area" in QGIS refers to the measure of the two-dimensional space occupied by a polygon feature. In other words, it is the size of the area enclosed by the polygon's boundary. QGIS provides a tool to calculate the area of features in square units (such as square kilometers or square miles) based on the projection of the map.

To calculate the area of a polygon in QGIS, you can follow these steps:

  1. Open your QGIS project.
  2. Make sure the layer containing the polygon features is visible and selected.
  3. Right-click on the layer in the Layers panel and select "Properties."
  4. Go to the "Fields" tab.
  5. Click on the "Add Field" button.
  6. In the "Add Field" dialog, specify the name of the new field (e.g., "Area"), the field type as "Real" or "Integer" depending on the precision you need, and the unit of measurement (e.g., "m²" for square meters, "km²" for square kilometers, etc.).
  7. Click "OK" to add the field.
  8. Go back to the main QGIS window.
  9. Right-click on the layer again and select "Open Attribute Table."
  10. Right-click on the row of the polygon whose area you want to calculate and select "Calculate Geometry."
  11. In the "Calculate Geometry" dialog, choose the "Area" option from the dropdown menu and specify the unit of measurement.
  12. Click "OK" to calculate the area and populate the new field with the result.

Alternatively, you can use the "Measure tool" in QGIS to manually measure the area of a polygon by tracing its boundary. The area will be displayed in the status bar as you trace.

Please note that the area calculation in QGIS is accurate only if the geometry of the polygon is correct. If the polygon has self-intersections or gaps, the area calculation may not be accurate.