Welcome to QGIS Tutorial. Today, we are going to show you how to clip a vector layer using polygon on QGIS. I am using QGIS version 3.0 on this tutorial. If you still using older version, you can freely upgrade your QGIS installation to version 3.0. In some cases, you may need to clip your existing vector layer against a polygon in another layer. In this article I will demonstrate how to cut or clip a layer using polygon on another layer.
Below is the contour layer with a polygon layer on top of it. I will clip the contour layer using the polygon.
The final result will look like this
First, open both layers (the one that we will clip and the polygon to clip against). Next go to Vector | Geoprocessing Tool | Clip. On the next window, select the input layer, clip layer and clipped layer. See the following example.
Click Run in background to start the clipping process.