I will get contour lines of electromagnetic field strength around power lines. The contours will be calculated by different agencies using different models. We need to check whether the resulting zones (x meter from power line) around the power lines are similar between models/agencies. There is no 'gold standard' because it is not possible to actually measure the field strength on the ground. Furthermore, the zone is not simply a straight line because in some situations two power lines cross or approach each other and we are most interested in these deviating situations. Is there a way in GIS to compare the modelling results (polylines/contours) among each other?
There are many ways. You could for example compare the ratios of the mutual area and the diffrence. Or you could check the Hausdorff distance of the polygons. Probably you should combine the two.