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I have the point location of vegetation surveys conducted on a river network. I would like to calculate the area of the contributing drainage basin upstream of each point using a DEM.

This image shows what I would like to do, which is to calculate the area above the red line/upstream of the point.

How can I do this with GRASS GIS, QGIS or SAGA GIS?

enter image description here

Can anyone help?

marked as duplicate by whyzar, Community Nov 12 '18 at 14:23

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