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5.3 Evaluation of the Result and Discussion 
The four training areas were classified correctly by the 
computer. It also showed a large area as expansive soil. 
The area has been left open by the city authorities as 
unsuitable for construction purposes due to presence of 
expansive soil. Thus the classification looks correct. In 
addition, site investigation at a few additional places 
confirm the accuracy of the classification. However this 
cannot be taken as a satisfactory ground check which 
will need elaborate and expensive drilling. The authors 
do not have a clue on how this can be done. By applying 
several band combinations involving different satellites 
and using different classification routes it is hoped a 
satisfactory and stable solution at the remote sensing 
stage can be achieved. The results from different sources 
and through different techniques are to be combined for 
which a satisfactory algorithm has to be developed like 
the one in Wang and Civco (1994). Elaborate site 
investigation will then be attempted to establish 
reliability of application of the remote sensing technique 
to mapping of expansive soils in the arid environment of 
Oman. A final point is relevant: remote sensing is 
basically a surface investigation technique. Also it 
employs almost exclusively the only criterion , tone, 
whereas human pattern recognition could involve about 
nine parameters (Lucas and Frans, 1994). Expectation 
from remote sensing as a tool for solving the present 
problem should therefore be tempered with reality till we 
come across any smart system which will be able to 
incorporate other criteria in the pattern recognition 
process. 
6. ACKNOWLEDGMENT 
Laboratory reflectance studies of a few expansive 
materials specimens were done in Boston University 
under the guidance of Dr. Farouk El-Baz. This is 
acknowledged. 
7. REFERENCES 
Ali, M.M.A., (1995). Mapping of expansive soil using 
remote sensing technique. B.Sc. Project Report 
(unpublished), Civil Engineering Department, Sultan 
Qaboos University, Al-Khod, Sultanate of Oman. 
Al-Rawas, A.A. and Woodrow, LK.R., 1992. The 
Distribution of expansive soils in Oman. Proceedings of 
the Seventh International Conference on Expansive 
Soils, Dallas, Vol. 1, pp. 432-437. 
Al-Rawas, A.A., McGown, A., Woodrow, L.K.R. and 
Sivakugan, N., (1995). The expansive soils and rocks of 
Oman. Proceedings of the Eleventh European 
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