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I have a river outlined: enter image description here

Using QGIS, the Semi-automatic Classification plugin and Landsat 8 images I classified the habitats (blue=water, yellow=sand/rock...,green=vegetation/algae) inside the river polygon across multiple years: enter image description here

I then created 50 sections along the length of the river dividing it equally: enter image description here

How do I derive habitat area statistics in meters (using WGS84 CRS for the layers) for each of these equal sections? enter image description here

I want to relate habitats to river bird abundances, comparing each sample's (river section's) habitat to its birds!

  • Did you consider creating a buffer? As you already have the line sections... – Matte Apr 18 '16 at 12:02
  • @Matte I did consider it however, the buffer tool does not create flat edges (like I need in the last screenshot) but rather the results overlap into adjacent sections? – Rion Lerm Apr 18 '16 at 12:07
  • Understood. How many sections there are? An completly automatic procedure is pretty hard (but possible i think, with quite some math for the directions and straight-segments). Did not know of one for Qgis. If manually is an option i would first move your river with the line displacement tool from the advanced digitizing toolbar. And then you can just digitize with the trace-digitizing tool on the start and end vertex and connect the 3 lines into a polygon ( you can also try to get this to work in python as you have start/end points and all needed segments). Qgis 2.14 would be needed. – Matte Apr 18 '16 at 20:04
  • @Matte there are about 45 sections. I am running 2.14 Essen. I wonder if just splitting the polygon feature at the line segments will work. Gonna take some time though but, wont be too lengthy procedure. – Rion Lerm Apr 19 '16 at 6:29
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    Using the line segment layer I split the vector into 50 different lines and placed in one folder. Secondly, I applied v.buffer to each segment with Batch Processing. Lastly, I merged the 50 buffers again. v.buffer provides for flat end caps! – Rion Lerm Apr 19 '16 at 9:50

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