Changing vector extent in QGIS

Question

I've been looking for a manner to change a vector extent in QGIS, but it's unsuccessfull!

I want change extent because in the past, I had problems to convert vector to raster. I try present the problem bellow:

I'm InVEST user. InVEST is a set of models developed by Natural Capital Project to mapping, quantifying and valuing Ecosystem Services. A while ago, I had a problem with the Carbon model. Actual LULC and Future LULC are input datas beside others. When I analysed this datas I perceived different extents. The model uses the extent when converting vector to raster during processing, therefore the Actual LULC pixels and Future LULC pixels did not fit properly. Another model's process is map algebra. When model executing map algebra, the results present a pattern due to LULC datas misalignment. I corrected this problem using the same extent for two LULC data.In ArcGIS the way to acomplish this task is very simple.

I was ArcGIS user. I've been using QGIS recently. ArcGIS and QGIS work with extent in different ways? Are there a manner to change vector extent in QGIS?

Answer 1

It sounds like your vector layers do not share a common extent. Decide on an extent (it can be no larger than your smallest vector layer and must either match or be within the of the extents of each layer you wish to use) then clip all your input vector layers to this common extent.

You can use Extract Layer Extent under Layer tools in the Processing toolbox and use the result to clip your input layers.

Or alternatively can use the extent of the visible map canvas by typing the following in the Python console.

print(iface.mapCanvas().extent())

Or toggling this button in the status bar at the bottom of the screen

You can then use Extract/Clip by Extent, under Vector Overlay in the Processing toolbox, to clip your input vector data to a uniform extent.

Answer 2

The extent of vectors cannot be changed as it is the extent of its features. As I understand Your problem has arisen due to misalignment which was caused due to the different extents of vectors, due to which the rasters also have different extent. The solutions is to align the rasters among themselves by resampling. In the Raster Menu Bar, there is Align Rasters... tools which will resample the rasters to a common extent.