On the contrary, QM and WT
present points of positive anomaly (up to 30%) on some basins of
the Massif Central. According to WT, the area of positive anomaly
on the Massif Central is larger and also presents some positive
anomalies on the south eastern extreme of the area. WT disagrees
with the other methods on the east part of the region, where it is
dryer. If the stations are compared one to one, there are differences
in sign in some stations and differences in magnitude that can attain
30%. These uncertainties are important.