I have assigned the elevation and the volume flow to each point at a river (with
v.what.rast). Now I want to calculate the Elevation difference between each pair of points and then calculate the Hydropower between them by using
P=density * Q * delta_h * g.
Here you can see an example of my Attribute Table (I know the differences are too small but it is only an example):
I don't know how to do this. Is there a way in GRASS or how can I realize that?
OK, I know how to Calculate the Hydropower with given Elevation difference (SQL Builder (Update) -> Field Calculator)). It works fine to multiply different rows. But one step is in my opinion not feasible with that: To Calculate the differences between Elevation as shown above (I cannot say something like: Elevation=i+1 - Elevation=i). Is there another Way?
Maybe to calculate it directly in GRASS and not in the Attribute table?