The applicability of detailed soil surveys limited to small reference areas
to larger regions should be assessed using easily available data. This is
done in this paper by computing at each site of the large region a mathemat
ical distance between local soilscapes and those in the reference area. Soi
lscapes are represented by a cover frequency vector of elementary landscape
classes (combinations of soil-forming factor classes) calculated within an
area defined around the site under consideration, The application of this
technique to four reference areas located in the Herault-Libron-Orb valleys
in the south of France demonstrated that: (1) the proposed soilscape dista
nce was in good agreement with the degree of representativity of a referenc
e area (i.e. percentage of soil classes already encountered in the referenc
e area), (2) representative areas of different size and purity can be delin
eated from a soilscape distance map by applying a distance threshold, (3) e
xpertise in delineating a reference area has a strong influence on its perf
ormances, i.e, size vs. purity of representative area. This suggests that t
he soilscape distance tested in this paper could be integrated in a classif
ication procedure defining the optimal size and location of future referenc
e areas. (C) 2001 Elsevier Science B.V. All rights reserved.