| Abstract: | A major problem in soil classification for soil survey is the lack, or uncertainty, of correspondence between mapping units in different localities. The problem is examined using multivariate soil data recorded at short regular intervals along transects in Oxfordshire and Aberdeenshire. The data for each transect were transformed to canonical variates, the first two of which were then used to locate soil boundaries and to show the relationships among the sampling points in that projection of the character space. With few exceptions, the sampling points in adjacent segments on all three transects lay in different parts of the canonical variate (CV) plane, showing that the boundaries were well defined. On the transect near Witney, Oxfordshire, distant segments either occupied distinct parts of the CV plane, or were superimposed on it. For the other two transects the portions of the CV plane occupied by some segments overlapped only partially the space occupied by one or more other segments that were not contiguous on the transects. The results show that on two of the three examples, lack of correspondence between mapping classes in different localities is already present in small tracts of country. |
