18.32. Planning a solar farm¶

Module contributed by Paolo Cavallini - Faunalia

First of all, create an aspect map from DTM:

• GRASS ‣ r.aspect [Data type: int; cell size:100]

In GRASS, aspect is calculated in degrees, counterclockwise starting from East. To extract only South facing slopes (270 degrees +- 45), we can reclassify it:

• GRASS ‣ r.reclass

with the following rules:

225 thru 315 = 1 south
* = NULL

You can use the text file reclass_south.txt provided. Note that with these simple text files we can create also very complex reclassifications.

We want to build a large farm, so we select only large (> 100 ha) contiguous areas:

• GRASS ‣ r.reclass.greater

Finally, we convert to a vector:

• GRASS ‣ r.to.vect [Feature type: area; Smooth corners: yes]

Exercise for the reader: repeat the analysis, replacing GRASS commands with analogous from other programs.