چكيده لاتين :
During recent years several attempts have been made to
incorporate environmental and natural resources degradation into
national accounts. GNP as measured by the traditional system of
national accounts does not consider environmental degradation
caused by inefficient exploitation of natural resources. While the
complete omission of environmental impacts is not possible, there
could be an optimal level of environmental degradation. However,
environmental degradation cannot be quantified easily. Therefore,
there is a need for a different approach to estimate the level of
environmental degradation so that it can be accounted for in the
GNP. In such cases where sufficient data are not available,
especially for the past, the fuzzy logic method is practical. This
paper applies the fuzzy set theory to estimate the trends of
environmental degradation in Iran in the period 1959-1998.
