I´m new with the use of PyQGIS and I´m working in a problem applied to a water supply systems modelling, where I need to distribute the water demand in about 5000 nodes (network junctions).
I´m using PyQGIS to calculate the water demand in each node.
Regarding to the working layers:
A. Junctions (Node layer): in this node layer I have to write in the “DEMAND” field, the result of the demand calculation.
B. NodeArea: it is a polygon layer with a Vonoroi polygons with the area on influence of each node (Junction).
C. NodePopulationDensity: it is a polygon layer with the different population densities in the different areas of the network.
The DEMAND result to be written in the Junctions layer will be the result of:
(Junction Demand, in A) = (Junction area, from B) x (Population Density, from C) x (per capita Water Demand, a constant).
Is there any easy way to intersect the A layer with the layers B and C, collect data from them, calculate and write the result in A?