  This Note is concerned with the asymptotic behavior of the minimal KPP speed
of propagation for reaction- advection-diffusion equations with a large drift
Mq (where q is the advection). We first give the limit of the speed as
M\rightarrow+\infty in any space dimension N. Then, we give the necessary and
sufficient condition that the advection field should satisfy so that the speed
acts as O(M) as M \rightarrow+\infty.
