Worksheet 3

Question 1

What is Snapping?

Answer 1

Snapping is when your cursor automatically aligns with the nearest vertex on the screen within a set range. It’s helpful for precise placement of cursor over vertices or on top of other features. You can adjust the snapping tolerance, which determines how far the cursor ‘jumps’ to align with a vertex. Snapping can be enabled or disabled in the settings menu under options → digitizing → toggle ‘Enable snapping by default’. Be cautious not to set the snapping tolerance too high, as it may make cursor control difficult by snapping to vertices within the specified distance

Question 2

Splitting Layers in GIS

Answer 2

Breaking up a single layer is a powerful GIS operation, enabling the creation of new information from existing data. This capability will be utilized in the next section when we discuss buffering.

Question 3

Buffer Analysis in GIS

Answer 3

Buffer analysis is used to identify areas surrounding geographic features like points, lines, or polygons. It’s a vector analysis that cannot be performed on raster layers. The process involves creating a buffer zone around existing features and then selecting features based on whether they fall inside or outside the buffer boundary. In the butterfly project, buffer analysis is used to identify areas within 200m of suitable roads for the interpretative center and within 50m of footpaths and butterfly sightings for nature reserve boundary placement.