Undulating to D Mod. well coinciding, 5c, 7b Moderately well coinciding 
rolling on diorite on ERTS-1 map schists units are more generalized 
and schists are included; compa- in soil map of Bad&joz 
rison difficult 
IS s-l 
o S 
a g 
- 213 - 
For the Mérida Region, Spain, independent interpretations on colour composite 
enlargements of ERTS-1 imagery (scale 1 : 250,000) show a better coincidence 
with existing soil maps than interpretations on the standard 9 inch format, scale 
1:1, 000, 000. This may be explained by the fact that a lot of information stored 
on the ERTS image is better retrieved on enlargements. However, the amount of 
observations also plays an important role. It should be noted that the 1 : 1, 000, 000 
scale ERTS interpretation map for a generalized soil survey was done with a mi 
nimum of field check and that a considerably longer period was spent on verifi 
cation for the Physiographic Soil Map scale 1 : 250, 000 based on ERTS imagery. 
2 
Experiments with the I S Colour Additive Viewer have revealed a better discrimi 
nation of some landforms in other band, filter, and illumination combinations 
than the simulated false colour image (4-blue, 5-green, 6-red). A methodology 
should be developed for further study. The best combination probably depends 
highly on the physiography of the area and the season in which the imagery was 
taken, apart from the quality (resolution, contrast) of the original products. 
REFERENCES 
1. BURINGH, P. 
1960 
2. F AO 
1966 
3. GOOSEN, D. 
1967 
4. GOOSEN, D. et. al. 
1973 
5. GUERRA DELGADO, A. et. al. 
1968 
6. GUERRA DELGADO, A. , y 
MONTURIOL, F. 
1968 
7. INST. GEOL. y MINERO 
DE ESPAÑA 
1965 
The application of aerial photographs in 
soil surveys. Manual of photographic 
interpretation. Amer. Soc. Photogr. , 
Washington, D. C. , pp. 633-666. 
Guidelines for soil profile description. 
Soil survey & fertility branch, Land and 
water development division, FAO, Rome. 
Aerial photo-interpretation in soil survey. 
Soil Bull. 6, FAO, Rome. 
Soil survey and photo-interpretation in the 
Guadiana Valley, Spain, ITC Journal, 
1973-3, pp. 449-463. 
Mapa de Suelos de España, Peninsula y 
Baleares, Escala 1:1, 000, 000. Inst. Nac. 
Edaf. y Agro. , Madrid. 
Mapa y explicación del Mapa Provincial 
de Suelos, Escala 1:250, 000. Diputación 
Prov. de Badajoz. Inst. Nac. Edaf. y Agro. , 
Madrid. 
Mapa Geológico de España y Portugal, 
Peninsula y Baleares, Escala 1:1,250, 000, 
la edición, Madrid.