I am quite new to QGIS and am trying to use QGIS 3.6 to create a raster layer of calculated values of the minimum distance of each cells within a polygon (orange) from a vector (the river channel in blue).

However, I need to limit this distance calculation to just the area within the fully displayed orange polygon and don't want the cells within the polygon calculating their minimum distance to vectors (channels) outside the polygon. I have nearly 200 of these polygons each of which represents the catchment area of a specific point and will need to replicate this raster calculation for all of these polygons. Could anyone help shine a light?

Polygon bound

Raster and Vector (channels)

  • I think you can do this with the Proximity (raster distance) tool. First convert the relevant stream and polygon into a raster. Use rasterize to convert the polygon. Burn stream network into dem might work for adding the stream. Once you find a workflow that works for a single stream and polygon, use the Graphical Modeler to turn that workflow into a model for batch processing. – csk Jul 11 '19 at 21:32

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